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1.01

THINkS: A Novel Tool for M ultiscale CFD Calculations of

Human Blood Circulation

Dr. P. George Huang Professor and Chair

Department of Mechanical and Materials Engineering

Wright State University

Dayton, OH 45435

Ph: +1 937 775 5043; Email: George.huang@wright.edu

Abstract

Computational Fluid Dynamics (CFD) is emerging as a tool for better assessment and management of cerebral

aneurysms. CFD calculations are often restricted to a small arterial zone and the solution is sensitive to boundary

conditions prescribed. A 1D simulation of the complete vessel network, THINkS (Total Human Intravascular NetworK

Simulation), is introduced to better describe the boundary conditions and to provide an overall flow information of the

complex vessel network.

As the governing equations for the blood flow in human vessel system can be casted in the same form as the gas dynamic

equations, the traditional shock capturing scheme can be modified to solve the hemodynamic equations. In this talk

we will discuss an in-house computer program - THINkS. THINkS consists of a simulation of 85 major arteries, 158

major veins, 43 arterial and 77 venous junctions. Blood flow in arterioles, capillaries and venules is modeled using

lumped parameter models, or the 0D models, which are modeled using the connection of a number of capacitors,

resistors and inductors to represent the real physics. The model used a simple 0D model for 20 one-artery-to-one-vein

micro circulations and 4 other 0D models for 7 complex arteries-to-veins micro circulations. Moreover, a 4-chamber 0D

model for the heart is used to allow blood to pump from superior vena cava I and inferior vena cava I veins, through

the pulmonary system, and discharge back to the ascending aorta artery. In addition to the 4 valves inside the heart,

there are also 15 venous valves used in the venous system.

THINkS calculations indicated usefulness of the model in predicting the trends of cerebral flow patterns. THINkS

solutions were validated with a number of in vivo experimental data and the agreement was excellent. A comparison

with experiments for the impact of incomplete circle of Willis (CoW) to the flow patterns was also made and the trend

shows an excellent agreement with reported data. THINkS allows for more accurate boundary conditions for 3D zonal-

based CFD calculations. THINkS has been validated against available experimental data and shown to respond correctly

to the flow pattern change caused by the variation in CoW. It provides the detailed flow information of the entire

human body including cerebral vessel network. Our aim is to use THINkS to generate accurate flow assessments, guide

treatment plans, and more reliably predict risks associated with vascular lesions.

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1.02

M easurement and Observation of Elementary Transition Boiling

Process after Sudden Contact of Liquid with Hot Surface

Yuichi MITSUTAKEa, Suhaimi ILLIASb, Koutarou TSUBAKIb,

Mohammad Nasim Hasanc, Masanori MONDEd aInstitute of Ocean Energy, Saga University, 1 Honjo-machi, Saga-shi, Saga Japan

bDepartment of Mechanical Engineering, Saga University, 1 Honjo-machi, Saga-shi, Saga Japan

cDepartment of Mechanical Engineering, Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh

dReserch Cemeter for Hydrogen Industrial Use and Storagey,Kyusyu University, 744 Motooka,Nishi-ku, Fukuoka-shi, Fukuoka Japan

Abstract

A Fast response surface temperature measurement technique has been developed to investigate transient transition

boiling phenomena after ethanol droplet impact on a nickel hot surface. Our motivation is to make clear the mechanism

of boiling transition between nucleate and film boiling which is closely related the recovery of wetting on the hot surface

being higher than the Leidenfrost temperature. In this study transient boiling phenomena during sudden contact of an

ethanol sessile droplet on a hot solid surface has been investigated to understand what governs whether the solid surface

keeps wet or not. The droplet impact boiling system is very simple and easier to observe but it includes the elementary

transition boiling process. Since the transient transition took place within a couple ten milliseconds, observation with

high speed video system and fast response surface temperature measurement technique are essential for better

understanding of the transition boiling phenomena.

The experiments were conducted for single and multiple droplet impacts. The multiple droplet impacts simulates liquid

and solid contact situations on a hot surface during spray or laminar jet quench. The nickel disk of 50 mm in diameter

and 5 mm in thickness was used as the hot surface. The hot surface was inclined from 0 deg (horizontal) to 40 deg. The

fast-response film thermocouple with a typical minimum response time of 80 microseconds was developed and fabricated

on the nickel disk at the depth of 3 micrometers from the surface. The temperature histories just beneath the surface

were recorded at the sampling frequency of 200 kHz. The boiling phenomena beneath a sessile droplet impacted on the

hot surface were observed by using a microscope equipped with the high speed video camera at the maximum frame

rate of 22.5 kfps. The surface temperature and surface heat flux were estimated with 1D inverse heat conduction

analysis. Histories of local surface temperature and local heat flux were compared with the boiling video image. The

experiments were done for different initial wall temperatures up to 250 oC, different liquid subcoolings from 33 to 53

K. The multiple impact frequency was changed from 280 to 840 Hz.

In case of the single droplet impact tests, the observation results showed that wetting situation was maintained for very

short time even though the surface temperature was beyond the liquid superheat limit temperature. We defined the

vapor film generation time as the characteristic boiling transition time scale from wetted nucleation boiling regime to

dry film boiling regime. The film generation time were measured for the extensive initial surface temperature range,

different subcoolings and different impact velocities. As the initial surface temperature increased, the film generation

time decreased to order of microsecond and film boiling situation seemed to be established via spontaneous nucleation

(vapor explosion) process. In case of the multiple droplets impact tests, film generation times were evaluated every

droplet impact during continuous cooling from the initial solid temperature. As long as the generation time was less

than 1 millisecond and much shorter than the impact period, stable film boiling was observed. Then the film generation

time increased with the droplet impact times and approached to the droplet impact period as the cooling time elapsed.

This region was recognized as the transition boiling region. After the generation time reached to the droplet impact

period and then stable wetted situation, namely nucleate boiling was observed. As compared with the single impact

tests, the generation time for the multiple impact became shorter than that for the single droplet impact at same initial

surface temperature and the lower limit surface temperature observed vapor film generation was reduced. This fact may

imply the effect of transient heat conduction on the wetting temperature shifts to higher wall superheat temperature

beyond liquid superheat limit temperature during quenching with jets or sprays.

Keywords: Fast-response temperature measurement; Transient transition boiling; Droplet; Wetting phenomenon

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1.03

The Advanced Technology and Future Prospect of OTEC in

Japan and the World - for Stable Energy &Sustainable Water

Resource Yasuyuki Ikegami, Saga University, Japan

Abstract

Europe and America and Korea have been promoted the practical use of the marine renewable energy forward on a

large scale project by the strong leadership of these governments while an energy problem and an environmental problem

of the 21st century on a global scale have been increasing in the acuteness and emergency degrees. The renewable ocean

energy (ROE) is strongly expected worldwide at practical use to be next to photovoltaic power generation, wind power

generation as enormous energy resources and a point of the job creation.. The activity of Japan on ROE has been

evaluated as world top-level at the laboratory level, by the way, Japan is delayed in the actual large proof R&D in the

sea area in the other countries more than ten years. Recently, Japan with a few resources has begun to be aimed at the

innovation of the ROE development full-scale as the sixth useful area in world, so-called exclusive economic zone (EEZ).

This year, the NEDO announced the technical road map toward 2030 of ROE including ocean thermal energy

conversion(OTEC) and the wave power generation.

Saga University has investigated on REO as only COE on REO in the whole country. Especially, OTEC has been

researched as aim at the practical use for about 40 years. OTEC is a system generating electricity with temperature

difference between warm sea water of the ocean surface and the cold sea water from depths 600m to 1,000m. The 30kW

OTEC device which Saga University has is evaluated on as the device that performance is the highest now in the world.

The characteristic of OTEC is stable and multi-purpose, not only the electricity but also seawater water conversion,

hydrogen production, lithium collection, the fishing ground reproduction is possible. Saga university has contributed to

the development of sustainable energy and water resources that these Japanese technology is asset to the project in

U.S.A., France, India, Taiwan now In this session, the current status and future prospect are presented on ROE, mainly

on OTEC.

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1.04

CFD, In vivo and In vitro Studies for Biofluid Circulations

Dr. Ing. Suh, Sang-Ho Dept. of Mechanical Engineering, Soongsil University, Seoul, Korea

Abstract

Arterial diseases are being increased and the pathogenesis of hemodynamic mechanism of the development and

progression of vascular disorders such as atherosclerosis and aneurysm are being investigated. Development of clinical

diagnostic techniques has been so limited to define the pathobiological role of atherosclerosis. FSI (Fluid Structure

Interaction) and flow visualization is a good tool to analyze the vascular flow patterns. CFD, FSI and In vitro experiment

can helps to predict pathogenesis of the biofluid circulation problems and also applied to development of clinical

diagnostics technique. Atherosclerosis is a progressive disease characterized by inflammation and lipid accumulation in

the vascular wall, Obstructive sleep apnea (OSA) is a syndrome characterized by repetitive episodic collapse of the

upper airway, and ureter obstruction occurs when urine flows in parallel in the bore and in the surrounding annulus of

a stent. The purpose of this study is to analyze flow patterns in the left coronary artery, upper airway, and ureter using

numerical and experimental techniques. Here we analyzed flow patterns and hemodynamic factors using numerical

techniques. We analyzed FSI (Fluid Structure Interaction) simulations in the left coronary artery, upper airway, and

ureter double J-stent 3D models which were carried out from CT scanned images and meshing done by CFD. The inflow

and outflow boundary conditions were applied from CT data for flow analysis. A Navier-Stokes governing equations

were discretized by finite volume method for numerical simulations. FSI analysis were performed of left coronary artery

to get the hemodynamic factors and flow visualization done by rapid prototype model, obstructive sleep apnea performed

flow characteristics in the upper airway to emerging concepts of ventilator control mechanisms in the normal sleep

apnea versus sleep disordered breathing, and ureter obstruction flow analysis of the effects of the ureteral wall

compliance, the pressure difference between the ureteral inlet and outlet. In the coronary RP model, Youngs modulus and movement of coronary artery which affect hemodynamic and accordingly has an effect on atherosclerosis, and The

magnitude of the pressure gradient is regarded as the pressure effort required for breathing and extent the reduction of

pressure effort in the upper airway. These all results can be used to develop of clinical diagnostics techniques.

1.05

A new approach to anisotropy in wall-turbulent shear flow, and

with application to organised disturbances, when these are

present

P. K . Sen, Srinivas V. Veeravalli, S. Hegde and Ganapat i Josh i Department of Applied Mechanics, Indian Institute of Technology Delhi,

New Delhi 110-016, India

.

ABSTRACT

This paper takes a re-look at anisotropy in wall-turbulent shear flow, from the viewpoint of the primitive equations for

turbulence, i.e. without considering averages. The paper attempts to develop some simple rules for the anisotropic part,

and arrives at a logical definition of eddy viscosity and the turbulent shear stress tensor. The results are extended to

the constitutive equation for organised disturbances in turbulent shear flows, when such disturbances are present. The

model of Sen and Veeravalli (Sadhana 1998, 2000, 2007), for organised disturbances, seems to be vindicated.

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1.06

A M icro Industry with Closed Energy and Water Cycles for

Sustainable Rural Development

Padma Vasudevan Sena, P.K. Sena, S. Hegdea, S.N. Singha, A. Mukhopadhyayb,

Prahalad Singhc, Philip Daviesd, R. Berryd, P. K. Deyd and Cyrus Engineere aDepartment of Applied Mechanics, Indian Institute of Technology, Delhi, India

bDepartment of Science and Technology, Delhi, India

cSchool of Desert Sciences, Jodhpur, Rajasthan, India

dAston University, Birmingham, U.K.

eIB Turbo Limited, New Delhi, India

Abstract

Sustainable development requires combining economic viability with energy and environment conservation and ensuring

social benefits. It is conceptualized that for designing a micro industry for sustainable rural industrialization, all these

aspects should be integrated right up front. The concept includes; (a) utilization of local produce for value addition in

a cluster of villages and enhancing income of the target population; (b) use of renewable energy and total utilization of

energy generated by co and trigeneration (combining electric power production with heat utilization for heating and

cooling); (c) conservation of water and complete recycling of effluents; (d) total utilization of all wastes for achieving

closure towards a zero waste system. Enhanced economic viability and sustainability is achieved by integration of

appropriate technologies into the industrial complex.

To prove the concept, a model Micro Industrial Complex (MIC) has been set up in a semi arid desert region in Rajasthan,

India at village Malunga in Jodhpur district. A biomass powered boiler and steam turbine system is used to generate

100-200 KVA of electric power and high energy steam for heating and cooling processes downstream. The unique feature

of the equipment is a 100-150 kW back-pressure steam turbine, utilizing 3-4 tph (tonnes per hour) steam, developed by

M/s IB Turbo. The biomass boiler raises steam at about 20 barg 3 tph, which is passed through a turbine to yield

about 150 kW of electrical power. The steam let out at a back pressure of 1-3 barg has high exergy and this is passed

on as thermal energy (about 2 MW), for use in various applications depending on the local produce and resources. The

biomass fuel requirement for the boiler is 0.5-0.75 tph depending on its calorific value. In the current model, the

electricity produced is used for running an oil expeller to extract castor oil and the castor cake is used as fuel in the

boiler. The steam is used in a Multi Effect Distillation (MED) unit for drinking water production and in a Vapour

Absorption Machine (VAM) for cooling, for banana ripening application. Additional steam is available for extraction

of herbs such as mint and processing local vegetables.

In this paper, we discuss the financial and economic viability of the system and show how the energy, water and

materials are completely recycled and how the benefits are directed to the weaker sections of the community.

Keywords: Trigeneration; Micro-industry; Sustainable development.

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2.01

Experimental Study on Heat Transfer and Friction Factor in

Laminar Forced Convection over Flat Tube in Channel Flow

Tahseen Ahmad Tahseena,c, M.M. Rahmana,b,* and M. Ishaka a Faculty of Mechanical Engineering, University Malaysia Pahang

26600 Pekan, Pahang, MALAYSIA

Phone : +609-424-2246; Fax : +609-424-2202

bAutomotive Engineering Centre, Universiti Malaysia Pahang

26600 Pekan, Pahang, MALAYSIA

c Department of Mechanical Engineering, College of Engineering

Tikrit University, Tikrit, IRAQ

Abstract

The heat transfer and fluid flow over a flat tube in the channel with laminar forced convection is experimentally

investigated. The experiments were conducted at a flat tube in the flow direction, the five air velocity between 0.2

and1.0 m/s, and Reynolds number based on the hydraulic diameter (ReDh) was considered from 124.5 to 622.5. The

uniform heat flux supplies are at the surface of the tube are 354.9, 1016.3 and 1935.8 W/m2 respectively. The

experimental results indicate that the average Nusselt numbers ( ) for the flat tube increased with increase of ReDh

at fixed of the heat flux supply. The increased with an increase of heat flux supply at fixed ReDh. On the other

hand, the friction factor decreased with increases of the front free stream velocity. The relationship with ReDh in

the power law, the ReDh correlation was found to be = (). The correlation achieved good

predictions of the measured data with the minimum root mean square value is 99.70%.

Keywords: Laminar forced convection; heat transfer; fluid flow; Reynolds number; heat flux; Nusselt number.

2.02

M HD Free Convection and M ass Transfer Flow through a

Vertical Oscillatory Porous Plate with Hall, Ion -slip Currents and

Heat Source in a Rotating System

Md. Delowar Hossain, Md. Abdus Samad and Md. Mahmud Alam Department of Mathematics,University of Dhaka, Dhaka-1000, Bangladesh

*Mathematics Discipline, Khulna University, Khulna-9208, Bangladesh

Abstract

Unsteady MHD free convection and mass transfer flow through a vertical oscillatory porous plate with hall, ion-slip

currents and heat source in a rotating system are studied. The governing equations of the problem contain a system of

non-linear coupled partial differential equations. The coupled non-linear partial differential equations are solved by

explicit finite difference method and the numerical results have been calculated by Compaq Visual 6.6a. For good

accuracy, stability and convergence analysis have been analyzed. The results of this investigation are discussed for the

different values of the well-known parameters and are shown graphically.

Keywords: MHD flow, Hall current, Ion-slip current, Suction parameter, Heat source parameter.

Page | 37

2.03

Two-phase frictional multiplier correlation for the prediction of

condensation pressure drop inside smooth horizontal tube

Md. Anowar Hossaina,, Hasan MM Afroza, Akio Miyarab aDepartment of Mechanical Engineering, Dhaka University of Engineering & Technology, Gazipur,

Bangladesh

bDepartment of Mechanical Engineering, Saga University, Saga shi 840-8502, Japan

Abstract

In the present work, a two-phase frictional multiplier (v) correlation for the prediction of condensation pressure drop

inside smooth horizontal tube has been proposed incorporating the effect of mass velocity, tube geometry and surface

tension. Other existing correlations and the newly proposed correlation of two-phase frictional multiplier have been used

to predict the condensation pressure drop of R1234ze(E), R32, R410A, dimethyl ether (DME) and

R1234ze(E)/R32mixtures (30/70 and 45/55 weight %) inside a horizontal smooth tube. The predicted results have been

compared with the available experimental data which is done inside a water heated double tube heat exchanger. The

test section is a horizontally installed smooth tube with effective length of 3.6m and inner diameter of 4.35mm. The

experiment has been carried out under the conditions of mass flux varying from 147 to 403 kgm-2s-1 and the saturation

temperatures ranging between 30 and 45 C, over the vapor quality range 0.0065 to 0.9724. From the results of

comparison, proposed correlation shows better performance for all refrigerants. Proposed v correlation can predict all

the experimental data within 11%.

Keywords: Condensation; R1234ze(E); frictional multiplier; R1234ze(E)/R32 mixture.

2.04

Geometric effect on magnetohydrodynamic convection in a half -

moon shaped cavity filled with water having semi-circular bottom

heater

Khan. Md. Rabbi, Towkir Ahmad, Satyajit Mojumder, Sourav Saha, Md. Zobayer

Hossain Department of Mechanical Engineering, Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh

Abstract

Magneto-hydrodynamic convection has been gaining attention due to its wide range of application. In this paper

magneto-hydrodynamic convection in a half-moon (semi-circular) shaped cavity has been analysed. The cavity has two

semi-circular bottom heaters and effect of distance between this two heaters has been thoroughly investigated for two

different cases ( = 0.1, 0.4). Numerical simulation has been carried out for a wide range of Rayleigh number (Ra = 103 ~ 107) and for Hartmann number (Ha = 0 ~ 100) to understand the flow and thermal field. Galerkin weighted

residual method of finite element analysis has been adopted for numerical solution along with code validation and grid

independency test to ensure the numerical accuracy. It has been found that strengthening of magnetic field tries to

reduce the heat transfer rate, whereas increment of heater distance augments the heat transfer rate. Results analysed

on the basis of Nusselt number and average fluid temperatures are shown by related contours, plots and graphical

analysis. Therefore, higher heat transfer rate has been achieved for = 0.4.

Keywords: MHD convection; Bottom heater; Rayleigh Number; Hartmann Number; Magnetic Field.

Page | 38

2.05

The Enhancement of Heat Transfer in a Circular Tube with

Insert and without Insert by using the Finite Element Method

Sabbir Hossaina, Ujjwal Kumar Debb, Kazi Afzalur Rahmana aMechanical Engneering Department, Chittagong University of Engineering and Technology

bDepartment of Mathematics, Chittagong University of Engineering and Technology

Abstract

This paper presents a Finite Element based model of the heat transfer problem. The Enhancement of heat transfer with

mass in a tube has been investigated without insert and with insert i.e. combination of horizontally and vertically

arranged rectangular boxes of 5 mm thickness are being fitted perpendicular to the flow direction respectively at equal

distance from each other along the length. The combinations are composed of without insert, two inserts, four inserts,

six inserts, eight inserts and ten inserts. The purpose of using inserts is to scatter the fluid particles in the laminar flow

which increases the heat transfer. An 800 mm long pipe with 26 mm inner diameter and 5 mm thickness is considered

in our simulation. The simulations have been completed for both stationary and time dependent conditions with

Reynolds number 1600~2400. A constant heat flux is generated at the boundary layer of the tube close to the flowing

fluid around the boundary layer. We also have shown the comparisons of heat transfer rate among different combinations

of inserts to understand the heat transfer phenomenon for the computational domain.

Keywords: CFD Analysis, Mass transfer, FEM Analysis, Boundary heat flux, Boundary element

20.6

Effect of Corner Radius of a T- Junction M ini-Square Channel on

Fluid Flow and Heat Transfer in the Developing Region: A Three

Dimensional Numerical Simulation.

Abhik Majumdera, Sambit Majumderb

aNational Institute of Technology, Agartala, 799055, India

bNational Institute of Technology, Agartala, 799055, India

Abstract

In recent years, there is a trend of miniaturization of devices like heat exchangers, microfluidic devices, MEMS and

electronic chip devices. The study of fluid flow in these devices is of great significance nowadays. Due to small

dimensions, the entrance design is a matter of concern and importance. In this work, the effect of variation of corner

radius, on thermo- hydrodynamic characteristics of a three dimensional model of T-junction square mini-channel duct

of 2 mm sides is studied under constant heat flux applied (H2 type) on the horizontal part. The length of horizontal

section is 300 mm. The T junction is placed at the middle of 60 mm long vertical section. The numerical simulation

was done in general purpose CFD package FLUENT. The simulation is performed for two Reynolds number, one in

laminar flow range (Re 1000) and the other in turbulent flow range (Re 3200). It is observed that incorporation of fillets

at T-junction changed the nature of the fluid flow and heat transfer locally. Variations in velocity and Nusselt number

have been observed in both the laminar and turbulent flow regime. Within developing region local velocity is found to

be increasing with increase in corner radii towards downstream of the channel in laminar and turbulent flow. Whereas

the local Nusselt numbers are less as compared to base model for all heating conditions and corner radii, resulting in

local wall temperature rise. Hence, such incorporation of corner radii may accelerate the uniform flow velocity growth.

Vortices are observed to be diminishing near the junction with increase in corner radii.

Keywords:T junction; corner radius; heat transfer; fluid flow; local Nusselt number.

Page | 39

2.07

Natural convection of fluid with viscous dissipation and variable

viscosity from a heated vertical wavy surface

Nazma Parveen and Md. Abdul Alim Department of Mathematics, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh

Abstract

A numerical analysis used to simulate the effects of the viscous dissipation and variable viscosity on natural convection

heat transfer boundary layer flow along a vertical wavy surface has been investigated. A simple coordinate

transformation is employed to transform the wavy surface into a flat plate. The boundary layer equations and the

boundary conditions are discretized and solved numerically using by the finite difference scheme known as the Keller-

box method. Effects of the viscous dissipation and variable viscosity parameter on the skin friction coefficients, the local

Nusselt number, the streamlines as well as the isotherms are presented and discussed in detail. The results of this

investigation illustrate that the skin friction coefficient increases with an increase of the variable viscosity and viscous

dissipation parameter, while the local Nusselt number at the heated surface decreases with increasing variable viscosity

and viscous dissipation parameter.

Keywords: Viscous dissipation; variable viscosity; natural convection; uniform surface temperature; Keller-box method;

wavy surface

2.08

Effect of magnetic field on natural convection in a C -shaped

cavity filled with ferrofluid

Satyajit Mojumder, Sourav Saha, Sumon Saha, M.A.H. Mamun Department of Mechanical Engineering , Bangladesh University of Engineering and Technology,Dhaka-1000.

Abstract

In this paper, natural convection heat transfer has been analyzed for a C-shaped cavity filled with ferrofluid. Cobalt-

kerosene ferrofluid is selected here for different solid volume fractions ( = 0 ~ 0.15). Galerkin weighted residual method is applied to obtain the numerical solution. Simulations are carried out for a wide range of Rayleigh (Ra = 103 ~ 107)

and Hartmann (Ha = 0 ~ 100) numbers for both the ferrofluid and the plain fluid. From this work, it is found that

higher Rayleigh number enhances the heat transfer rate significantly, whereas presence of magnetic field tries to retard

convection. Moreover, addition of 15% solid volume fraction of nanoparticle can augment the heat transfer rate up to

52.65% at moderate Rayleigh number compared to the base fluid. By an optimization of these parameters, effective

heat transfer control equipment can be developed. Results are interpreted on the basis of streamline and isotherm

patterns, and average Nusselt number of the heated wall and average fluid temperature of the cavity.

Keywords: Ferrofluid; C-shaped cavity; Magnetic field; Natural convection.

Page | 40

2.09

Soret and Dufour effects in an M HD flow over a porous rotating

disk using HAM

Navid Freidoonimehra, Mohammad Mehdi Rashidib,c, Mohammad Shakhaoath

Khand, Mohammad Ferdowse aYoung Researchers & Elite Club, Hamedan Branch, Islamic Azad University, Hamedan, Iran

bMechanical Engineering Department, Engineering Faculty of Bu-Ali Sina University, Hamedan, Iran

cMechanical Engineering Department, University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University,

Shanghai, Peoples Republic of China

dDepartment of Chemical Engineering, University of Newcastle, NSW 2308, AUSTRALIA

eDepartment of Mathematics, University of Dhaka, Dhaka-1000, Bangladesh

Abstract

The main concern of the present article is to study the steady MHD flow past a porous rotating disk using a semi

numerical/analytical method named Homotopy analysis method (HAM). The von-Karman transformations are

employed to transform the governing equations into system of nonlinear ordinary differential equations (ODEs). The

results of the present study are compared with numerical quadrature solutions employing a shooting technique with

excellent correlation in an especial case. The effects of flow physical parameters such as magnetic interaction parameter,

suction parameter, Prandtl number, Schmidt number, Soret and Dufour number on the fluid velocity, temperature and

concentration distributions are presented graphically and discussed in details. Results show that the effect of increasing

Soret number or decreasing Dufour number tends to decrease the temperature distribution while enhances the

concentration distribution.

Keywords: Heat and mass transfer; MHD flow; Rotating disk; HAM; Soret effect; Dufour effect

2.10

Effect of fin and insert on the performance characteristics of

Open Loop Pulsating Heat Pipe (OLPHP)

M Lutfor Rahmana , Fariha Mira*, Sumaiya Nawrina, R A Sultana, and

Mohammad Alib aDepartment of Mechanical Engineering, MIST, Mirpur, Dhaka, Bangladesh

bDepartment of Mechanical Engg., BUET, Dhaka, Bangladesh

Abstract

The pulsating heat pipe, a serpentine tube of capillary dimension with many turns, has great impact on todays successful thermal management. It is an ascending technology to satisfy present requirement of increasing thermal

performance. Focusing on this, an experiment has been done on the open loop pulsating heat pipes (OLPHP) to observe

their performance characteristics by using two types of working fluid by varying inclination angles. The experiment is

performed on 2.5 mm inner diameter and 3 mm outer diameter OLPHP with an insert of copper wire of 1 mm diameter

and fins are added on the condensation section. This investigation is done using methanol and ethanol with 50% filling

ratio in OLPHP with 8 loops. In this experiment the effects on the performance of using fins with insert with two

different fluids (methanol and ethanol) and the variation of inclination angles are investigated. The results show that

the performance characteristics in all the circumstances are better for setup with fin and insert than the normal setup.

As higher thermal resistance indicates better performance, so we can say that setup with methanol performs better than

ethanol. This performance is best at 45 inclination angle. It can be seen that, higher the inclination angle, better the

performance and this performance is best at 45 inclination angle for this experiment.

Keywords: Open loop closed end pulsating heat pipe; evaporation; condensation; inclination angle; thermal conductance.

Page | 41

2.11

Experimental investigation on heat transfer characteristics of an

Open Loop Pulsating Heat Pipe(OLPHP) with fin

Md Lutfor Rahmana, Pijush Kanti Sahaa,*, Fariha Mira, Asfia Tanjim Totinia,

Sumaiya Nawrina and Mohammad Alib aDepartment of Mechanical Engineering, MIST, Mirpur, Dhaka, Bangladesh

bDepartment of Mechanical Engineering, BUET, Dhaka, Bangladesh

Abstract

This paper presents an experimental investigation of an open loop pulsating heat pipe of 2 mm inner diameter and 2.5

mm outer di0061meter with fin in condenser section to study the heat transfer performance. The setup is an open loop

closed end pulsating heat pipe creating a total of 8 loops with total length of 25 cm. The performance characterization

will be done for methanol as working fluid with 50% filling ratio. The evaporator section is 5 cm in length and the

condensation section is of 8 cm with an adiabatic section of 12 cm. The evaporator section is heated by electrical input

using Ni-Chrome wire and the condenser section is cooled by fan. The effects of fin in PHP for open loop will be analyzed

for heat transfer characteristics and the results are compared with that of without fin keeping constant the other

parameters. The results explore the possibility of using the open loop pulsating heat pipe as an integrated structure to

achieve higher thermal conductance to the host substrate. Effect of gravity, pressure differential in the system,

temperature, heat input etc. may have influence in this fact due to which 45 inclined position of finned structure shows the best performance.

Keywords: Open loop closed end pulsating heat pipe; evaporation; condensation; inclination angle; thermal conductance.

2.12

Study of Thermal Conductivity and M echanical Property of

Insulating Firebrick Produced by Local Clay and Petroleum Coal

Dust As Raw M aterials

Md. Hamidur Rahmana,*, Md.Tariqul Islama, Tamzid Ibn Minhaja, M.A.K.

Azada, Md.Mehedi Hasana and A.A.Md. Rezaul Haquea

aDepartment of Materials and Metallurgical Engineering

Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh

Abstract

Thermal insulation is one of the major requirements for various industrial applications. In this study the evaluation of

thermal conductivity and mechanical property of an insulating refractory was carried out at elevated temperature. As

additive, coal dust and 4-5wt% water were mixed with local clay. After forming the bricks by conventional uniaxial

pressing method, the samples were first air dried for 2 hours at ambient temperature of 30C, then oven dried for 8-10

hours at 110C and finally fired in furnace for 6 hours at 1050C. The combustion of fully combustible coal incorporated

extra porosity in the final products resulting in enhanced thermal insulation. As experimental variables, three different

sets of coal particle size range (coarse: 100-500 m, medium 20-100 m, fine: less than 20m) and four different coal

percentages were used. The results thus obtained showed that increased fineness of coal dust for a fixed coal percentage

improved crushing strength and porosity and decreased thermal conductivity. In contrast, for a fixed coal particle size

range, crushing strength and thermal conductivity decrease and the percentage of porosity increases with the increase

of coal percentage.

Keywords: Thermal Insulation; Fireclay; Coal dust; Insulating Refractory; Porosity; Thermal Conductivity.

Page | 42

2.13

Effect of fin and insert on the performance characteristics of close

loop pulsating heat pipe (CLPHP)

M Lutfor Rahman1, Sumaiya Nawrin1,, Rasel A Sultan1, Fariha Mir1,

Mohammad Ali2

1Military Institute of Science and Technology, Mirpur Cantonment, Dhaka-1216, Bangladesh

2Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh

Abstract

The pulsating heat pipe, a serpentine tube of capillary dimension with many turns, has great impact on todays successful thermal management. It is an ascending technology to satisfy present requirement of increasing thermal

performance. Focusing on this, an experiment has been done on the close loop pulsating heat pipes (CLPHP) to observe

their performance characteristics by using two working fluids with varying inclination angles of 0 (vertical), 30 and

45. The experiment is performed on 2.5 mm inner diameter and 3 mm outer diameter CLPHP with an insert of copper

wire of 1 mm diameter and fins are added on the condensation section where the evaporation section is 50 mm, adiabatic

section is 120 mm and condensation section is 80 mm.This investigation is done using ethanol and methanol with 50%

filling ratio in CLPHP with 8 loops. Methanol shows better performance at 45inclination than ethanol due to their

physiochemical properties at different conditions.In this experiment the effects on the performance of using fins with

insert and the variation of inclination angles are investigated. The results show the better performance characteristics

and enhancement of heat transfer in the present experimental set-up because of using fin and insert.

Keywords: Pulsating heat pipe; Thermal performance; Close loop pulsating heat pipe (CLPHP); Insert of Copper wire;

fin on condensation section

2.14

An experimental investigation on the effect of fin in the

performance of closed loop pulsating heat pipe (CLPHP)

M Lutfor Rahman1, Rasel A Sultan1,, T Islam1, Noor M Hasan1, Mohammad Ali2

1Military Institute of Science and Technology, Mirpur Cantonment, Dhaka-1216, Bangladesh

2Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh

Abstract

Pulsating heat pipes (PHP) have created a newer arena and promising possibilities as passive devices for heat transfer

applications, especially suited for thermal management of electronics. A closed loop pulsating heat pipe (CLPHP) made

of copper with 2 mm ID and 2.5 mm OD with fin in the condenser section is used in the present work to evaluate the

heat transfer performances where the evaporation section is 50 mm, adiabatic section is 120 mm and condensation

section is 80 mm. The attempt is to analyze and compare the effects on the heat transfer performances of CLPHP with

finned and un-finned condenser section with inclination angle of 0 (vertical), 30 and 45. Methanol is used as working

fluid with 50% filling ratio in CLPHP with 8 loops during the experimentation. The experimental results indicate a

strong influence of gravity and thermo physical properties of the working fluid on the performance of the CLPHP

studied with different orientation and heat load. The results demonstrate the effect of fin used in condenser section, the

input heat flux, inclination angle orientation and physiochemical properties of the working fluid on the thermal

performance of the device. The finned CLPHP at 45 inclination exhibits the considerable enhancement of heat transfer

compared with that of CLPHP without fin.

Keywords: Electronic Cooling; Pulsating heat pipe (PHP); Close loop pulsating heat pipe (CLPHP); Thermal

performance

Page | 43

2.15

Effect of Waste Heat Recovery on Drying Characteristics of

Sliced Ginger in a Natural Convection Dryer

Jnyana R. Patia , Santosh K. Hottaa, , P. Mahantab a Centre for Energy, Indian Institute of Technology, Guwahati- 781039

b Department of Mechanical Engineering, Indian Institute of Technology, Guwahati- 781039

Abstract

In the present work, quality drying characteristics of sliced ginger were studied utilizing the concept of waste heat

recovery in a biomass operated natural convection dryer with sensible heat storage material (SHSM) and phase change

material (PCM). Ginger slices (2 and 4 mm thickness) were dried from initial moisture content (MC) 88-90 % (w.b.) to

final moisture content 11-12% (w.b.) with hot air maintained at temperature 600C, air velocity 0.2 m/sec, atmospheric

average relative humidity 74% and ambient temperature 250C It was observed that the biomass consumption and

melting time of PCM were significantly reduced due to the use of waste heat. The optimum drying time was found to

be 5.5 h for 2 mm thick ginger slices. Color, texture and aroma were found better in treated sample.

Keywords: Waste heat recovery; Natural convection dryer; Phase change material; Quality drying

2.16

Ground source heat pump system controlled by refrigerant

average density

Koutaro Tsubakia*, Yuichi Mitsutakea aSaga University, Honjo 1, Saga, 840-8502, Japan.

Abstract

A ground source heat exists in a ground shallower than about 100 m in depth. The ground source heat was applied for

heat pump for air conditioning and snow melting, etc. However it is not popular in South area of Japan. We focus on

the ground source heat application in warm region, especially for air cooling. The ground temperature at isothermal

layer, about under 5m depth, is constant at about 18 C in Saga, Japan. This temperature is lower than the temperature

required for air cooling. Then a heat pipe with ground source heat can be used instead of a heat pump with atmosphere

heat source, usually used for air cooling. Heat pipe could operate with smaller energy consumption than heat pump.

Nevertheless the cycle operated like heat pipe is not used for ground heat source application. The novel ground source

heat application cycle, which could operate as heat pump and heat pipe, suit for an air cooling was investigated in this

research. The cycle operation condition is controlled by the average density. The cycle simulation of this cycle is

investigated. From the calculation results, heat transfer rate and exergy loss of cycle changed with refrigerant average

density. And also the best density condition was changed with the heat source temperature. Heat pipe operation could

operate as 1.32 times (R410A) and 1.34 times (R407C) higher the heat transfer rate per unit the total irreversible loss

compared with heat pump operation (P = 0.1 MPa). And heat pump operation (P = 0.1 MPa) could increase a heat

transfer rate 1.23 times (R410A) and 1.29 times (R407C) compared with heat pipe operation.

Keywords: Ground source heat; Heat pump; Heat pipe; Air conditioning

Page | 44

2.17

Thermal Diffusion Effect on Unsteady Viscous M HD M icropolar

Fluid Flow through an Infinite Vertical Plate with Hall and Ion -

slip Current

Nisat Nowroz Anikaa, Md. Mainul Hoqueb, Sheikh Imamul Hossainc

and Md. Mahmud Alamc

aDepartment of Mechanical Engineering, The University of Newcastle, Callaghan, NSW 2308, Australia

b*Department of Chemical Engineering, The University of Newcastle, Callaghan, NSW 2308, Australia

cMathematics Discipline, Khulna University, Khulna-9208, Bangladesh

Abstract

An analysis is carried out to study the effect of Hall and Ion-slip current and heat transfer characteristics over an

infinite vertical plate for micropolar fluid in the presence of magnetic field. The governing boundary layer equation first

transformed into non-dimensional form and resulting non-linear system of partial differential equations are then solved

numerically by using the robust implicit finite difference technique. Also the unconditional stability and convergence

test has been carried out to establish the effect of shear stresses, couple stress, Nusselt number and Sherwood number

on the flow field. Finally, the effects of various parameters are separately discussed and shown graphically.

Keywords: Micropolar fluid; Hall current; Ion-slip current ; Thermal diffusion.

2.18

Effects of geometric parameters on the flow characteristics for

turbulent flow in a wavy finned-tube heat exchanger: CFD

modeling

Arafat A. Bhuiyan1,3, , M.Ruhul Amin2 and A K M Sadrul Islam3 1Faculty of Science, Engineering and Technology, Swinburne University of Technology, VIC-3122, Australia.

2Department of Mechanical Engineering, Montana State University, Bozeman, Montana,MT 59717-3800, USA

3Department of Mechanical Engineering, Islamic University of Technology (IUT), Gazipur-1704, Bangladesh.nt

Abstract

In this study, the effects of thermal and hydraulic characteristics of wavy fin and tube heat exchanger are investigated.

Simulation has been carried out by a commercial computational fluid dynamics code, ANSYS CFX12.0. The main

objective of this study is to investigate the flow characteristics in turbulent flow. Results are predicted for the turbulent

flow regime (2100Re7000) and compared with authors previous work for laminar (400Re1200) and transitional (1300Re2000) flow regime. Regarding turbulence, the k- model was used to predict the turbulent flow characteristics with 5% turbulence intensity. Predicted results were compared with the experimental data for the purpose of validation

and the discrepancy is found within 10% in error range. Parametric study was conducted for different pitches and wavy

angles. Flow characteristics obtained for the turbulent range is in line with the pattern observed in laminar and

transitional ranges. This study demonstrates a clear understanding and relationship of among different flow ranges and

the effects of different geometric parameters on the performance of heat exchanger.

Keywords: Wavy fin tube heat exchanger, CFD modelling, Friction factor, Colburn factor, Efficiency index, Reynolds

number.

Page | 45

2.19

Experimental investigation of transient heat transfer on a solid

surface, with fire retardant fabric under hot air impinging jet

A.K.M. Nazrul Islama, , Md. Ashraful Islama, Manabendra Sahab aDepartment of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh

bCentre for Energy Technology, School of Mechanical Engineering, The University of Adelaide, SA 5005, Australia

Abstract

This paper represents an experimental investigation of the transient heat transfer on a solid base plate (mimic to skin)

covered by fire retardant fabric (Kevlar 49), under hot air jet impingement. The study was carried out by a fabricated

attachment with an axial flow wind tunnel for horizontal hot air jet impingement. The hot air jet was impinged on a

vertical base plate at different velocities and temperatures. A set of experimental conditions was considered to

understand the various heat transfer phenomenon. The hot air jet temperatures were 115 and 125 oC respectively and

jet velocities were 12, 15, and 19 ms-1 respectively at the exit point of the nozzle. The surface temperatures of the solid

base plate are used to calculate the heat flux, local heat transfer coefficient, and Nusselt numbers. The maximum heat

transfer is found on base plate, whilst the maximum decrease of heat flux is observed on fire retardant fabric. This

experimental model can enhance the understanding and insights of the heat transfer process through permeable fabric.

Keywords: Heat transfer; jet impingement; fire retarding fabric; Nusselt number.

2.20

Natural Convection Flow and Heat Transfer in an Enclosure

Containing Staggered Arrangement of Blockages

Draco Iyia and Reaz Hasanb

aDepartment of Mechanical Engineering, School of Engineering Robert Gordon University, Aberdeen, AB10 7GJ, United Kingdom

bDepartment of Mechanical and Construction Engineering, Northumbria University at Newcastle upon Tyne, NE1 8ST, United Kingdom

Abstract

The work reported in this paper is a numerical study of airflow and heat transfer for low turbulence buoyancy-driven

flow in a rectangular cavity partially filled with solid objects. The two vertical walls were maintained at constant

temperatures giving a temperature differential of 42.2 C resulting in a characteristic Rayleigh number of 1.45109. Two

different types of blockage arrangements were considered for analysis, and these consist of In-line and Staggered

arrangements of 126 and 123 objects. In all cases, steady state flow and wall heat transfer data at the mid-height

and mid-width of the cavity are presented. The flow domain displayed a stable core region and the average core

temperature was found to be strongly influenced by different stacking arrangement of solid objects. In general, the

staggered arrangement resulted in lower heat transfer through the surfaces which is linked with the suppression of

turbulence within the boundary layers close to the surfaces.

Keywords: Low turbulenc, Natural convection, Heat transfer, CFD, Product stacking and arrangement

Page | 46

2.21

Thermal and hydraulic performance analysis of rectangular fin

arrays with perforation size and number

Mehedi Ehteshum, Mohammad Ali, Md. Quamrul Islam, Muhsia Tabassum Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh

Abstract

Enhancement of heat removal and reduction of fin size become a major concern in designing heat exchanger equipment.

The present paper reports an experimental analysis to investigate the turbulent heat transfer performance of rectangular

fin arrays, both solid and circular perforations along the length of the fins. The size and number of circular perforation

have been varied. Tests have been conducted in a horizontal wind tunnel equipped with forced draft fan. The data are

obtained by varying flow velocities while maintaining constant heat input and taken over a period of time. The Reynolds

number is varied between 6104 through 25104. The heat loss due to radiation and convection is taken into account

during calculation. Thermal performances and effectiveness of perforation and equivalent surface solid fin arrays have

been evaluated and compared. Results show remarkable heat transfer enhancement, lower thermal resistances, pressure

drop and higher efficiencies, effectiveness for perforated fins with increasing number of perforations in addition to the

considerable reduction in weight in comparison with solid fin arrays.

Keywords: Perforated fins; Turbulent flow; Fin effectiveness; Heat transfer; Heat transfer enhancement; Perforation

size; Perforation number;

2.22

Analysis of Heat Transfer in Channel Flow Subject to Sine -Bump

Heating

Umera Sarjanaa, M. Zakir Hossainb, AKM Monjur Morsheda aDepartment of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka.

bDepartment of Mechanical and Materials Engineering, University of Western Ontario, Ontario, Canada.

umera.sarjana@gmail.coma zakir92@yahoo.comb mmmsumon@gmail.coma

Abstract

Convection in a channel subject to a distributed sinusoidal bump like heating applied at the lower wall has been studied.

It is found that small wave number heating provides large plumes whereas large wave number heating provides a

uniform temperature distribution at the upper part of the channel. Heat transfer is more efficient at low Reynolds

number with small wave number heating.

Keywords: Convection; Heating; Reynolds number; sinusoidal bump;

Page | 47

2.23

Effect of a DC Field on Temperature Distribution in a Thin FGM

M etal Line Subjected to Distributed Local Heating Sources

Abhishek Kumar Ghosh, Md. Rejaul Haque and S. Reaz Ahmed Bangladesh University of Engineering and Technology, Dhaka- 1000, Bangladesh

Abstract

The effect of a direct-current field on the temperature distribution in a thin, non-uniform functionally graded metal line

subjected to distributed local heat sources is investigated. The material properties of the metal line are assumed to vary

over the span following a linear functional relationship. Bump-like heat sources of different profiles are considered to

simulate the condition of distributed local heating of the metal line. The governing differential equations associated

with the electrical and thermal problems are derived in terms of variable thermal and electrical conductivity of the

material. The solution of the coupled boundary-value problem is then obtained using a finite-difference computational

scheme. The temperature distributions in the FGM line are determined for different environmental conditions as a

function of intensity of the DC field.

Keywords: Functionally-graded metal line; distributed heat source; temperature distribution; direct-current field.

2.24

Dean-Taylor Flow with Convective Heat Transfer through a

Coiled Duct with Strong Curvature

Rabindra Nath Mondala , Raju Royb and Md. Zohurul Islamb a Department of Mathematics, Jagannath University, Dhaka-1100, Bangladesh

b Department of Mathematics and Statistics, jessore University of Science and Technology , Jessore-7408, Bangladesh.

Abstract

The present study addresses numerical prediction of Dean-Taylor flow through a coiled rectangular duct of curvature

0.5. Spectral method is used as a basic tool to solve the system of non-linear partial differential equation. The emerging

parameters controlling the flow characteristics are the rotation parameter i.e. , (incorporating Coriolis force), Grashof

number , Prandtl number , aspect ratio , and pressure-driven parameter i.e. Dean number Dn (incorporating

centrifugal force). The flow structures are examined for the effects of rotation parameter and pressure-driven parameter.

We investigated unsteady flow characteristics for two cases of the duct rotation, Case I: Positive rotation and Case II:

Negative rotation. For positive rotation, we investigate the unsteady flow for the Dean numbers Dn = 1000 and 2000

over the Taylor number , and it is found that the chaotic flow turns into steady-state flow through periodic or multi-

periodic flows, if Tr is increased in the positive direction. For negative rotation, however, unsteady flow characteristics

are investigated over the Taylor number , and it is found that the unsteady flow undergoes through various flow

instabilities, if Tr is increased in the negative direction. Contours of secondary flow patterns and temperature profiles

are obtained at several values of Tr, and it is found that the unsteady flow consists of two-, three-, four-, five-, six-,

seven- and eight-vortex solutions. Convective heat transfer is also investigated, and it is found that the chaotic flow

enhances heat transfer more significantly than the steady-state or periodic solutions.

Page | 48

2.25

M HD free convection fluid flow through parallel plates with hall

current in a rotating system

Rina Perven, Md. Mahmud Alam

Mathematics Discuipline,Science, Engineering and Technology School, Khulna University, Khulna-9208, Bangladesh

Abstract

An attempt has been made to study the influence of inclined magnetic field with hall current of a viscous incompressible

electrically conducting free convection fluid flow through the parallel plates in a rotating system. The channel is rotating

with uniform angular velocity about an axis normal to the plates. For numerical solution, the problems have been

transferred into dimensionless form and then the explicit finite difference technique has been used. The stability

conditions and convergence criteria of the explicit finite difference scheme are established for finding the restriction of

the values of various parameters to get more accuracy. The effects of Rotation parameter R , Hall parameter m ,

Magnetic parameter 2( )M and Angle of inclination on primary and secondary velocities have been shown in

graphical representations. Finally the effects of these parameters have been analyzed by the figures of local shear stress

and average current density at the moving plates of channel.

Keywords: Hartmann number; Rotating system; MHD free convection; Inclined magnetic field; Finite difference

technique

2.26

Effects of viscous dissipation on natural convection flow over a

sphere with temperature dependent thermal conductivity in

presence of heat generation

Md. Raihanul Haquea, Md. M. Alama, Mohammad Mokaddes Alib, Rehayet Karimc, a Department of Mathematics, Dhaka University of Engineering and Technology, Gazipur-1700,Bangladesh

b Department of Mathematics, Mawlana Bhashani Science and Tech. University, Tangail-1902, Bangladesh

c Department of Mathematics, Chittagong University of Engineering and Technology, Chittagong-4349, Bangladesh

Abstract

In this paper, the steady two-dimensional laminar incompressible flow over a sphere in the presence of viscous dissipation

and heat generation is considered. Thermal conductivity is assumed as a linear function of temperature. The governing

equations are solved numerically by numerical solution strategy as per requirement and suitability. The obtained self

similar equations are then solved numerically by an implicit, tri-diagonal, finite-difference method with Keller Box

scheme. Favorable comparison with previously published work is performed. Computations are performed for a wide

range of the governing flow parameters such as thermal conductivity variation parameter , heat generation parameter

Q, Prandtl number Pr and Eckert number Ec. The computational findings for the dimensionless velocity, temperature

profiles as well as for the skin-friction coefficient and heat transfer rate are presented in tabular form and graphically.

Keywords: Variable thermal conductivity; Heat generation; Eckert number

Page | 49

Page | 50

3.01

Transient Analysis of 3-Lobe Bearings Considering Surface

Roughness Effect For A Gas Turbine

Nabarun Biswasa,Prasun Chakrabortib

a*Department of NIT Agartala,Jirania,Tripura-799046,India

bDepartment of NIT Agartala,Jirania,Tripura-799046,India

Abstract

The performance of a 3-lobe bearing is investigated by means of three-dimensional computational fluid dynamics

analysis. Surface roughness effects were included in the computation of unsteady transient analysis of 3-lobe bearing,

taking into account gravity. Each of the lobes is placed at a distance of 120 degree. In this paper K-Epsilon turbulence

model is used. The 3-lobe bearing is designed in Gambit software, the journal is modeled as a moving wall with an absolute rotational speed of 6000 rpm. Design parameters like L/D ratio, total pressure distribution, surface roughness

and lubricant flow properties like turbulent viscosity and velocity magnitude are considered for the analysis The flow

is simulated using Ansys Fluent software.

Keywords: 3-lobe; viscosity; pressure; wall shear stress; surface roughness.

3.02

Experimental investigation on the performance of NACA 4412

aerofoil with curved leading edge planform

M. Nazmul Haquea*, Mohammad Alia , Ismat Araa

aDepartment of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh.

Abstract

Aircraft wings are the lifting surfaces with the chosen aerofoil sections. The efficiency as well as the performance of an

aircraft mostly depends on the aerodynamic characteristics e.g. lift, drag, lift to drag ratio, etc of wings. Besides many

factors, the effects of wing shape are also crucial to aircraft performance. This paper represents the experimental

investigation to explore better aerodynamic performance by incorporating curvature at the leading edge of a wing. A

wooden model with straight leading and trailing edge i.e. rectangular planform and another model with curved leading

edge and straight trailing edge are prepared with NACA 4412 aerofoil in equal length (span) and surface area. Both the

models are tested in a closed circuit wind tunnel at air speed of 85.35 kph (0.07 Mach) i.e. at Reynolds number 1.82 x

105. The static pressure at different angles of attack (-4, 0, 4, 8, 12, 16, 20 & 24) are measured from both

upper and lower surfaces of the wing models through different pressure tapings by using a multi-tube water manometer.

From the static pressure distribution, lift coefficient, drag coefficient and lift to drag ratio of both the models are

analyzed. After analyzing the data, it is found that the curved leading edge wing planform is having higher lift coefficient

and lower drag coefficient than the rectangular wing planform. Thus, the curved leading edge planform is having higher

lift to drag ratio than the rectangular planform.

Keywords: Aerofoil; aerodynamic performance ; coefficient of lift; coefficient of drag; lift to drag ratio; Reynolds number.

Page | 51

3.03

Experimental Study of Unsteady Flow in a Shock Tube for

Needle-Free Drug Delivery

Guang Zhang1, Yun Sung Kim2, Gyu Wan Kim3, Toshiaki Setoguchi4 and Heuy

Dong Kim1,2,3* 1. 2. 3. Department of Mechanical Engineering, Andong National University, Andong 760-749, Korea

Zhang1@anuis.andong.ac.kr1, kimhd@andong.ac.kr1*

4. Department of Mechanical Engineering, Saga University, Saga, Japan

setoguci@me.saga-u.ac.jp

Abstract

Recently, the needle-free delivery system has been widely used in medical fields due to its convenience in delivering

drug particles into human body without any external needles. In order to penetrate through the outer layer of the skin,

drug particles need to obtain enough momentum, which is achieved by accelerating drug particles in a Contoured Shock

Tube (CST). The CST consists of a micro shock tube with two diaphragms and an expanded supersonic nozzle. In the

present study, experimental studies were carried out by pressure measurement. Six high sensitive pressure transducers

were used for recording pressure changes as the shock wave moved through different locations along walls in the test

section. From which, data on shock wave propagation could be obtained. Different diaphragm pressure ratios were

conducted to demonstrate effects of initial diaphragm pressure ratios on shock wave propagation. Shilieren visualization

was also performed to observe shock wave propagation and shock wave structure in the present experimental shock

tube model. The characteristic of the internal flow and shock wave system have been studied and analyzed in details

in the present shock tube model.

Keywords: Shock tube, Supersonic nozzle, Needle-free drug delivery, Shock wave propagation, Unsteady flow.

3.04

An Empirical M odel for Annular Flow in Gas Wells

Aziz Rahman Assistant Professor, Department of Process Engineering, St Johns, NL, Canada

E-mail: marahman@mun.ca

Abstract

In annular flow of a natural gas well, liquid may be present in entrained droplets as well as in the film near to the well

wall. A number of models have been proposed over the past 50 years to predict film thickness in pipes with vertical

two-phase annular flow. Earlier models are based on correlations from the limited range of experimental data. The

proposed modified film thickness model developed from a range of experimental data. The experimental data covers

conditions of superficial liquid velocities ranging from 0.610-3 to 0.39 m/s; superficial gas velocities ranging from 13.4

to 110.6 m/s; and diameters ranging from 12 to 51 mm. The proposed model is compared with the available experimental

data in the literature. Model predictions are in good agreement with the available experimental data set. The modified

film thickness model helps to explain the fundamentals of annular flow, which in turn is beneficial to the natural gas

production industry as it further develops the understanding of production mechanics.

Keywords: annular flow; two phase flow; flim thickness; pressure gradeint; entranment; gas well;

Page | 52

3.05

W inglet Type Dielectric Barrier Discharge Plasma Actuators:

Performance Characterization and Numerical Comparison

A.N.M. Mominul Islam Mukuta, Hiroshi Mizunumab, Obara Hiromichib and

Takehiko Segawac aDhaka University of Engineering & Technology (DUET), Gazipur-1700, Bangladesh

bTokyo Metropolitan University, Tokyo 192-0397, Japan cNational Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan

Abstract

Winglet type dielectric barrier discharge plasma actuator (PA) with two exposed electrodes have been investigated

experimentally in a quiescent air and numerically modeled. Three arrangement of electrode positions are used: leading

edge type (here after L PA), middle edge type (here after M PA), and trailing edge type (here after T PA) to investigate

the effect of electrode position on induced flow. When the electrodes are located at the leading edge of the winglet PA,

the stream wise flow is effectively enhanced on the covered electrode; on the other hand when the electrodes are located

at the trailing edge, the friction loss is minimized for the near-wall high shear flow over the winglet and thus the highest

momentum integral is obtained for the downstream jet-like flow. As all three type of PAs have two exposed electrodes,

hence two separate jet flows are induced which are unified to a single jet after the winglet trailing edge. The electrode

location also influences the unification velocity at downstream. The longer distance between trailing edge and embedded

electrode reduces the downstream unified velocity. Particle image velocimetry (PIV) technique has been implemented

to investigate the flow field. Simulation results are found to be consistent and in good agreement with experimental

data.

Keywords: dielectric barrier discharge plasma actuator; velocity profile; flow control; PIV; jet; CFD

3.06

U ltra Compact Heat Exchanger W ith Geometry Induced Wall

Jet

A K M M. Morshed Morshed (Bangladesh), Fazlul Bari (Bangladesh), Aashique

Alam Rezwan Rezwan (Bangladesh)

Abstract:

Heat Exchanger (HX) is common but crucial equipment found in almost every engineering application which comes in

different types, sizes and shapes. Performance of the HX is directly related with the overall system performance.

Compactness of the HX is a good indication of its performance, usually the higher the compactness the higher the

effectiveness. Increasing compactness of the HX by reducing the channel dimension is fairly a simple but highly effective

technique. Although heat exchanger comprising of very small channel can achieve very high heat flux, its pumping

requirement for circulating liquid increases very sharply. The pumping requirement can be reduced by increasing the

number of channels either by vertical or horizontal stacking; the flow velocity through each channel is reduced for the

same total mass flow rate of the liquid. In this study a novel technique called geometry induced wall jet is proposed to

further enhance the performance of this heat exchanger comprising of small channels. The cross-flow from the wall jet

disrupts the boundary layer of the channel flow enhancing the heat removal capacity of the heat exchanger. A CFD

model has been developed using commercially available software package FLUENT to evaluate the overall thermal

performance of this new design heat exchanger. A parametric study of the flow rates and the effect of the jet locations

have been performed. Significant reduction in thermal resistance has been observed for proposed design.

Keywords: Heat Exchanger, Wall Jet, Heat Transfer Enhancemen

Page | 53

3.07

Numerical Study of Sub-Nozzle Flows for the Weft Transmission

in an Air Jet Loom

Jin Hyeon Kim1, Toshiaki Setoguchi2 and Heuy Dong Kim1* 1. Department of Mechanical Engineering, Andong National University, Andong 760-749, Korea

Kimjh1@anuis.andong.ac.kr1, kimhd@andong.ac.kr1*

2. Department of Mechanical Engineering, Saga University, Saga, Japan

setoguci@me.saga-u.ac.jp

Corresponding author: Prof. Kim, Heuy Dong (kimhd@andong.ac.kr)

Abstract

The air jet loom is widely applied in the textile industry due to its high productivity, convenient controllability, high

filling insertion rate, low noise and low vibration levels. High-Speed air jet weaves the weft yarn, and transports it

through the weft passage. In the present study, a computational fluid dynamics method is applied to solve the

incompressible NavierStokes equations with one-equation Spalart-Allmaras turbulence model. Which is used to solve the flow filed in a weft passage. The aim of this analysis is to determine the distribution of the flow velocity along the

weft passage. Results revealed the strong relationship between air jet velocity and forces on the weft.

Key words: Air Jet Weft Insertion, Main Nozzle, Sub Nozzle, Air Jet Loom, Profile Reed

3.08

A study on multistage centrifugal pump performance

characteristics for variable speed drive system

Rakibuzzamana, Sang-Ho Suha , Kim Kyung-Wuka, Hyung-Ho Kima, Min Tae

Chob, In Sik Yoonb aDept.of mechanical Engineering, Soongsil University, Seoul, 156-743, South Korea

bDooch Co., 295 Sagok-ri, Jangan-Myeon, Hwaseong-si, Gyeonggi-do, 445-942, South Korea

Abstract

Nowadays centrifugal pumps are being widely used in the commercial, industrial and power plant applications and most

of pumps operated by constant speed drive system. Therefore, pump consumes a huge energy of each nations total energy. But it could be operated in variable speed drive system which would be provided energy saving. The purpose

of this study is to investigate the pump performance characteristics of the multistage centrifugal pump with the variable

drive system. For this study an experimental set up of the system was constructed to achieve the centrifugal pump

performances such as H-Q, -Q, P-Q curves and operating points which interact between performance and system curves. In the variable speed drive system, a vector controlled inverter driving (variable voltage variable frequency) was

installed in the experimental system. A numerical investigation also applied for getting the pump performances for the

validation and reliability of the pump design development and also the pressure and velocity effects in internal flows of

the pump are analyzed. For the numerical analysis, the Navier-Stokes equations were discretized by the finite volume

method and two equations transport turbulence (SST) model accounts for three dimensional steady flows. In the

experiment system, we also carried out system head performance of the three pumps in parallel to compare with one

pump system head for its validation. In order to get the energy saving rate using the inverter control variable speed

drive system instead of the constant speed drive system, it is necessary to identify the specific duty cycle of the pump

operation cycle and operating system curve of the pump. Hopefully, this paper will be useful as a guide for identifying

a method of implementing a variable speed drive system with inverter control in the variable flow and pressure system.

Keywords: Multistage centrifugal pump; Variable speed drive system; Inverter; Performance analysis; System curve;

SST turbulence model;

Page | 54

Page | 55

4.01

Velocity and temperature distributions of laminar and transition

boundary layer flows along a heated vertical flat plate

Mohammad Zoynal Abedina,*, Mohammed Moinul Islama, Mashud Ranaa, Jinho

Leeb aDepartment of Mechanical Engineering, Dhaka University of Engineering & Technology, Gazipur-1700, Bangladesh

bSchool of Mechanical Engineering, Yonsei University, Seoul 120-749, Republic of Korea

Abstract

Time-developing direct numerical simulation (DNS) has been performed for the laminar and transition boundary layer

flows in the natural-convection and mixed-convection with aiding and opposing flows both in air and water along a

heated vertical flat plate. The results reveal that the velocity profile of water in the laminar natural-convection boundary

layer shows lower peak value compared to that in air and the temperature profile in water within the boundary layer

becomes ambient at a shorter distance perpendicular to the heated wall compared to that in air due to the effects of

higher Prandtl number of water. For laminar mixed-convection boundary layer, the velocity profile of water exhibits

lower values throughout the boundary layer compared to that in air. In the case of opposing flows both in air and water,

the velocity profiles show a sharp drop to a constant negative value in the outer boundary layer region. Furthermore,

for transitional natural-convection boundary layer in air, the magnitude of the velocity profile increases with an increase

in Grashof number due to the increasing trend in the boundary layer thickness. It is also found that the predicted heat

transfer rates in the natural-convection boundary layer both in air and water correspond quantitatively well with the

existing observations.

Keywords: Laminar flow; Transitional flow; Boundary layer, Freestream velocity, Prandtl number, Natural convection,

Mixed convection.

4.02

M odified NorrisReynolds OneEquation M odel M. M. Rahman1, A. K. M. Sadrul Islam2, M. J. Lampinen1 and T. Siikonen1

1Aalto University School of Engineering, P.O. Box 14400, FI00076 AALTO, Finland

2Department of Mechanical & Chemical Engineering,

Islamic University of Technology, Board Bazar, Gazipur 1704, Bangladesh

1E-mail: Mizanur.Rahman@aalto.fi

Abstract

A modified version of NorrisReynolds (NR) kequation turbulence model is proposed to account for the distinct effects

of lowReynolds number (LRN) and wall proximity. The turbulent kinetic energy k and the dissipation rate are evaluated using the ktransport equation in conjunction with the Bradshaw and other empirical relations. The eddyviscosity formulation maintains the positivity of normal Reynolds stresses and preserves the anisotropic characteristics

of turbulence in the sense that they are sensitized to rotational and nonequilibrium flows. The modified NR (MNR) model is validated against welldocumented flow cases yielding predictions in good agreement with the direct numerical simulation (DNS) and experimental data. Comparisons indicate that the MNR model offers some improvement over

the original NR model and competitiveness with the SpalartAllmaras oneequation model.

Keywords: Oneequation model, turbulence anisotropy, twolayer model, nonequilibrium flow.

Page | 56

4.03

Unsteady M HD Casson Fluid Flow through a Parallel Plate with

Hall Current

Md. Afikuzzaman, M. Ferdows and Md. Mahmud Alam Mathematics Discipline, Khulna University, Khulna-9208, Bangladesh

**Mathematics Department, Dhaka University, Dhaka-1000, Bangladesh

Abstract

Unsteady MHD Casson fluid flow through a parallel plate with hall current is investigated. The uniform magnetic field

is applied perpendicular to the plates and the fluid motion is subjected to a uniform suction and injection. The lower

plate is stationary and the upper plate is moving. Explicit Finite Difference technique has been used to solve the

momentum and energy equations. The effect of pressure gradient, the Hall parameter and other parameters describing

in the equations are shown graphically. Effect of decaying parameter with different Casson number on primary velocity,

secondary velocity and temperature distributions are illustrated in the form of the graph.

Keywords: MHD; Heat Transfer; Hall Current; Finite Difference Techniques.

4.04

Unsteady M HD viscous incompressible Bingham fluid flow with

hall current

Afroja Parvin*, Tanni Alam Dola** and Md. Mahmud Alam ** *The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34151 Trieste, Italy

**Department Civil Engineering, Bangladesh University of Engineering and Technology(BUET), Dhaka-1000, Bangladesh

***Mathematics Discipline, Science, Engineering and Technology School, Khulna University, Khulna-9208, Bangladesh

Abstract

An electrically conducting viscous incompressible Bingham fluid bounded by two parallel non-conducting plates has

been investigated in the presence of Hall current. The fluid motion is uniform at the upper plate and the uniform

magnetic field is applied perpendicular to the plate. The lower plate is fixed while upper plate moves with a constant

velocity. The governing equations have been non-dimensionalzed by using usual transformations. The obtained

governing non-linear coupled partial differential equations have been solved by using explicit finite difference technique.

The numerical solutions are obtained for momentum and energy equations. The influence of various interesting

parameters on the flow has been analyzed and discussed through graph in details. The values of Local Nusselt number,

Average Nusselt number, local Skin- Friction, Average Skin- Friction for different physical parameters are also

illustrated in the form of graph.

Keywords: MHD Flow; Hall parameter; Explicit finite difference technique; Stability analysis

Page | 57

4.05

Physics of supersonic mixing in parallel and non -parallel streams

passing over base thickness

Mohammad Ali , TAGMZN Jubery, Sanchita Amin, M Quamrul Islam Department of Mechanical Engineering, Bangladesh University of Engg. and Technology, Dhaka 1000, Bangladesh

Abstract

The mixing flow field of two-parallel and non parallel gaseous streams has been studied numerically. The streams are

of air and hydrogen and come into contact after passing over a finite thickness base. The two gas streams are delivered

from a high-pressure reservoir and entering into the domain with atmospheric pressure. The two-dimensional unsteady

Navier-Stokes equations, energy, mass diffusion and species continuity equations are numerically simulated to analyze

the mixing layer in supersonic flow field. An explicit Harten-Yee Non-MUSCL Modified flux-type TVD (total variation

diminishing) scheme is used to solve the system of equations. An algebraic turbulence model is used to calculate the

eddy viscosity coefficient. Keeping constant the inlet pressure and velocity of the streams, the merging angle is varied

to observe the physics of flow fields, mixing of two-streams and mixing efficiency. The results show that the increase of

merging angle causes stronger interactions between two streams, high momentum exchange and eventually enhancement

of mixing between two streams.

Keywords: Supersonic combustor, mixing, shear layers, merging angle;

4.06

Numerical investigation of effect of M ach number over backward

facing step

Konica Sarker *a , Mohammad Ali b , Quamrul Islam b a Bangladesh Power Development Board, Dhaka, Bangladesh.

b Department of Mechanical Engineering, BUET, Dhaka-1000, Bangladesh

Abstract

A numerical study has been carried out to investigate the flow field characteristics of a transonic compressible flow over

a flat plate with backward facing step. The study has been performed by solving Two-Dimensional Navier-Stokes

equations. The system of governing equations has been solved, using an explicit Harten-Yee Non- MUSCL Modified

flux type TVD scheme and a zero-equation algebraic turbulence model to calculate the eddy viscosity coefficient. The

results presented in this paper are computed for fixed step height, h=7.5 mm and for different Mach numbers, M= 0.8,

1.0 1nd 1.2. The details on pressure, temperature and velocity field, together with recirculation length, expansion shock,

reattached shock, interaction of shock wave are reported. The variations of flow field characteristics due to change of

Mach number are also presented.

Keywords:Mach number; backward step;recirculation;

Page | 58

Page | 59

5.01

Effects of Thermal Diffusion on Viscoelastic Fluid

Flow through a Vertical Flat Plate Sheikh Imamul Hossain and Md. Mahmud Alam1

Mathematics Discipline, Khulna University, Khulna-9208, Bangladesh

Abstract

Viscoelastic fluid flow through a semi-infinite vertical rigid plate with diffusion-thermo and thermal-diffusion has been

studied. To obtain the non-dimensional, coupled non-linear momentum, energy and concentration equations, the usual

transformations have been used. The obtained non-dimensional equations have been solved by implicit finite difference

technique. The stability and convergence analysis have been analyzed. From the above analysis, parameters restriction

have been obtained to calculate the converge results. The effects of the various parameters entering into the problem

on the velocity, temperature and concentration are shown graphically. Finally, a qualitative comparison with the

published results is shown in tabular form.

Keywords: Viscoelastic fluid, diffusion-thermo, thermal-diffusion, implicit finite difference method;

5.02

Aerodynamic study of FIFA-approved footballs

Firoz Alam, Harun Chowdhury*, Israt Mustary and Bavin Loganathan School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, 3083, Australia

Abstract

The game of football is worlds most viewed, played and loved sport. Due to increasing technological advancements and demand for performance, the ball manufacturers have been developing new designs progressively since its inception over

100 years ago. A traditional spherical football made of 32 leather panels stitched together in 1970s has become 14

synthetic curved panels thermally bonded without stitches in 2006 and more recently 8 panels thermally bonded in

2010, and again some new designed balls in 2013. Despite being most popular game in the world, no data is available

on aerodynamic properties of recently FIFA approved Adidas Cafusa (thermally bonded 32 panels), Nike Maxim

(stitched 32 panels), Umbro Neo 2 Pro (stitched 14 panels, and Mitre Ultimax (stitched 26 panels) footballs. Hence the

primary objectives of this study are to evaluate aerodynamic performance of these recently introduced balls and compare

their aerodynamic properties. The aerodynamic forces and moments are measured experimentally for a range of wind

speeds in wind tunnel. A field trial using professional players has also been undertaken. The aerodynamic forces and

their non-dimensional coefficients were determined and compared. The players perception was also discussed.

Keywords: football; FIFA; drag; wind tunnel; field trial; flow visualisation.

Page | 60

5.03

Bio-inspired design: aerodynamics of boxfish

Andrei Kozlov, Harun Chowdhury*, Israt Mustary and Bavin Loganathan and

Firoz Alam School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, 3083, Australia

Abstract

This paper investigates the aerodynamic behavior of a boxfish using both experimental and computational methods. A

scaled up model boxfish was manufactured and tested in RMIT Industrial Wind Tunnel under a range of Reynolds

numbers and yaw angles. The drag, lift and side forces and their corresponding moments were measured simultaneously.

A CAD model of the boxfish was used in CFX FLUENT Computational Fluid Dynamics (CFD) modeling. The CFD

modeling data were validated using the experimental findings. The results indicate that the drag coefficient of a boxfish

is around 0.10 which is significantly lower than current drag coefficient of a passenger car. Hence, a boxfish shape can

be adapted for achieving low drag and energy efficient motor vehicle design.

Keywords:0020 Passenger car; aerodynamic drag; box fish; wind tunnel; yaw angle; CFD.

5.04

Numerical investigation on the delay of boundary layer

separation by suction for NACA 4412

R.