5965_48_40_a Study of Turbulence Induced Forces Acting on the Blobe Valve_2005

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A Study of Turbulence Induced Forces Acting on a Globe

Control Valve Operating at Small Opening

A. Hassan1. and A. Sharara2

Abstract - Under certain opening conditions and partial opening of control valves, the piping

systems occasionally suffer large vibrations. To understand the valve instability that is responsible for such vibrations, experiments and CFD simulations were performed. As a result of the study of

the turbulence flow through a single seat globe valve operating at small openings, it was found

that a complex three-dimensional flow structure (valve attached flow) sets up in the valve regionleading to high pressure variations in the valve trim region. CFD calculations showed how a jet

may impinge on the roof of the valve body and cause a large-scale recirculation region in the pipedownstream of the valve. Moreover, it was found that the smaller valve opening, the larger the

exciting force acting on the valve stem. The harmful effect of the fluid flow forces (exciting forces)

is very much pronounced at relatively smaller valve opening. The simulation results for turbulent

flow with k model were more accurate than the k model. In addition, k model was

simpler and faster in convergence than the k model.

Keywords: Control valves – Turbulent – Simulation – Computational fluid dynamics.

I. Introduction

Control valves are used to control volumetric flow

rates and keep the regulated process variable as closeas possible to the desired set point. One of the most

common types of control valves is the single seat globe

valve. It consists of three main components: body, trim(which made up of the plug and seat), and actuator.

The trim of the control valve is responsible for theinherent valve flow characteristics. Different flow

conditions require different shapes of the plug and seat

to achieve optimum flow control. In severe serviceapplications; control valves are equally crucial for

safely dissipating high process fluid energy levels toavoid valve and piping damage from acoustic noise,

vibration, cavitations and erosion. To varying degrees,all of these potentially damaging phenomena scale with

flow velocities in the valve and valve trim, leading

some valve manufactures to recommended specific

limits to fluid kinetic energy )EK ( in the valve trim.

More recently, designers of fluid handling equipments

are using CFD simulation for product development

and optimization. In the present study, CFD has beencombined with experimental work to analyze the flowthrough globe control valve with a flat-faced plug,

operating at small opening.

II. Literature Review

Despite of the importance of control valves, a little

research work has been published on control valvedesign, especially for the globe control valves. In an

attempt to avoid a host of valve problems, Miller [1]

proposed applying valve trim maximum EK criteria

including component vibration, breaking parts,excessive aerodynamic noise, trim and/or valve pitting

and erosion caused by liquid cavitations or flashing andsurface erosion by solid particulate. Based on

operational experience, Miller and Stratton [2]

presented an allowable trim EK limit for a given

control valve application that depends on theapplication service conditions. The criterion involves

limits on the fluid EK existing from the valve’s trim.

They advocate a kPa485 limit to a clean flowing

process fluid, but suggested a kPa275 limit for

cavitating and multiphase trim flows. Hardin et al [3]studied three different plug design cut off, concave and

hybrid to eliminate the flow-induced instability of steam turbine control valves. They used a steady state

CFD model and found that the hybrid plug design is

the most convenient shape for the presented case.Wojtkowiak and Oleśkowicz-Popiel [4] carried out

numerical and experimental investigation on the flow

characteristics of butterfly valves. Flow patterns and pressure distribution in the disk vicinity were obtained.

The computational results, obtained from the standard

k-ε turbulence model, agree qualitatively with the

results of the experimental study. It is likely that moresophisticated turbulence model will yield quantitatively

more accurate values. Using the FLUENT code, Kim

[5] investigated a three dimensional numericalsimulation to analyze an incompressible flow through

the partially-opened thin-flap disk butterfly valve.



Chern and Wang [6], conducted a 3D numerical

simulations and experiments were conducted toobserve the flow patterns and to measure performance

coefficients when V-ports with various angles were

used in a piping system. Three V-ports with angles 30deg, 60 deg, and 90 deg were studied. It was found that

V-ports with angles 30 deg and 60 deg make the flowrate proportional to the valve opening. However, V-

ports increase the pressure loss between the inlet and

the exit of a ball valve. Davis and Stewart [7] studiedthe performance of a single seated globe valve by

applying Fluent CFD code. They showed that the

valve characteristics could be accurately predictedusing axisymetric flow models over most of the plug

travel. Hong et al [8] performed a numerical simulationfor the cavitating flow in hydraulic conical valves. The

structure of the valve was simplified as two

dimensional axisymmetric model. They found that the

cone shape have a considerable effect on the intensityof the cavitation. Amirant et al [9] studied theoretically

flow forces on an open center directional control valve.

The results showed that the flow force increases with

increasing the flow rate. Oza et al [10] presented aCFD model for a globe valve in oxygen applications.

They used both k and k models of turbulence

through the numerical computations. The simplifiedaxisymmetric model was used to predict the inherent

valve characteristic. Their results showed that the

k turbulent model is more suitable for boundary

level flow.

In the present study, the fluid flow around a single

seat globe valve will be treated as a three-dimensional

flow to focus on the details of the flow variations in the

valve region. An experimental study and CFDsimulation are conducted to understand the cause of the

fluctuations. The fluid flow force acting on the valvestem is measured and compared with the obtained

values from the numerical study to verify the numericalmodel.

III. Experimental Facility

An experimental test rig was designed on the basisof closed loop flow system. The test setup in Fig.1 is

driven by a 7.5 hp centrifugal pump and is capable of

providing hr m48 3 of water flow. The test rig

generates 400 kPa (4 bar) across the test valve at flow

rates up to 30 m³/hr. the rotational speed of the pump

may be adjusted via a frequency inverter to obtain adesired value of the water flow rate. The test section is

situated at the fully developed flow area and the back pressure can be controlled using a butterfly valve

downstream of the test section. A calibrated orifice

flow meter is used to measure the flow rate during the

experiments. Pressure transducers, which candistinguish millisecond fluctuations, are mountedupstream and downstream the globe valve to measure

the pressure fluctuations caused by the valve. The

upstream pressure 1P and downstream pressure 2P are

measured from static wall tapings located 5 pipediameter upstream and 11 pipe diameter downstream

of the valve. The mounting of the pressure transducersneeded special attention to avoid an influence to the

flow field [11]. The bonnet of the tested valve was

modified from a standard type (Fig.2-a) to an extendedtype (Fig.2-b) which included an S-type load cell tomeasure the flow net force acting on the valve and to

transmit it to the valve body. The sensing elements of the load cell, those subjected to bending moments.

Bending elements offer high strain level at relatively

low force, which makes them ideal for low capacityload cells. In the proposed design of the load cell, there

are two surfaces subjected to equal strains of oppositesign. This offers convenient means for implementing a

full bridge circuit, while temperature compensation is

relatively easy. Bending as a measuring principle offersexcellent linearity of the S-type load cell, which was

used in the experiments to measure the flow net force.Using CIO-EXP-GP signal conditioning board, the

time history signals have been collected and

transformed to DAS08-AO data acquisition card via a

37 pin connector cable.

III.1. Test Conditions

The hydraulic test and measurements have been

made at room temperature with flow rate up to

hr /m403 and a valve opening up to 40%. The

opening of the control valve was set using a dial gauge

indicator, which has a resolution of 0.01 mm. Thevalve’s opening was 5, 10, 20, 30, and 40 %;

respectively, and the maximum valve travel was 23

mm. The maximum pump outlet pressure was 5.7 bar,while the minimum back pressure of the valve was 0.3

bar.

III.2. Valve Characteristics

There are two important control valve parameters,

the overall flow coefficient vC and the relative valve

capacity dC . The flow coefficient vC is a measure of

valve capacity. It is given by the ISA standard S75.01

[12] for incompressible, fully turbulent, noncavitating

and nonflashing flow as

P

GQ6.11C f

v (1)

where f G is the specific gravity of the fluid. In the SI

system of units, the units of vC are

))kPa/()hr /m(( 5.03 . Equation (1) is applicable to fully

turbulent flow field for which valve parameters becomes independent of the Reynolds number. The

relative valve capacity factor dC is a measure of the



Entrance Pipe

Tested

GlobeValve

Butterfly

Valve

WaterTank

Isolation Ball ValveFilter

Isolation Ball Valve

Long

RadiusBend

Pump

Flexible

Joint

OrificeMeter

Upstream

PressureTransducer

DownstreamPressure

Transducer

FlexibleJoint

(a) Outline of experimental apparatus

(b) Overhead view of the test loop

Fig. 1. The experimental test rig.

valve capacity relative to its nominal pipe size pD , it is

given by

2 p

vd

)D0394.0(

CC (2)

and has units of )mm/()kPa/()hr /m( 25.03 . Values of

dC do not normally exceed 11, see [7]. The inherent

valve characteristic is a plot of vC versus percent

opening of the valve, which represents an indication

for how the flow rate will change with a change in

percent opening of the valve. The percent opening of the valve is a measure of how far the plug is stroked

relative to its maximum stroke length. The flow

coefficient vC is experimentally determined for

different valve openings or positions. For a constant

valve opening, ten test runs were made for turbulent

flows at high Reynolds numbers such that the flow

coefficient should remain constant, 5e 101R . Runs

were made at levels of heavy cavitation were avoided

because of the effect of cavitation on vC . The flow

coefficient was then calculated from the average of the

test runs at a constant valve opening, after excludingthe largest and smallest values. Valve position is

expressed in terms of percentage of full opening



(a) Standard (b) Modified

Fig. 2. Bonnet design of tested valve

)mm23( . For the purpose of test repeatability, valve

opening was always set and measured by opening the

valve to a given position. The experimental results

illustrated in Fig.3 show the inherent valve

1- Valve Body

2- Seat3- Plug

4- Stem

5- Bonnet6- Side Rod

7- Load Cell8- Lower Square Plate

9- Rigid Spacer 10- Nut

11- Side Guide12- Upper Square Plate

13- Handle

14- Dial Gauge



characteristic for the valve under investigation.

Accordingly, the test-valve was found to be of quick-opening type.

Fig. 3. Inherent valve characteristics

IV. Dimensional Analysis

The flow force acting on the valve stem 'F' depends

upon the volume flow rate 'Q', the valve opening or position 'l' , the valve diameter 'D', the upstream

pressure' 1P ', the pressure drop across the valve ' P ',

the viscosity of the fluid ' ', and mass density ' '. By

applying the Buckingham’s -theorem, a

dimensionless expression for the flow force acting onthe valve stem may be obtained as follows,

)D/(PD

Qf

DP

F32

1

(3)

where2

1 DP

Fis defined as the dimensionless exciting

force dF and )D/(PD

Q3

is defined as the

dimensionless volume flow rate dQ . The experimental

results shown in Fig.4 show the variation of the

dimensionless exciting force with the dimensionless

volume flow rate. The test runs were made at highReynolds numbers and turbulent flow at different flow

rates and pressure drops. The dimensionless force ' dF '

and the dimensionless volume flow rates were

calculated as the average of the test runs at a constantvalve position. The results show that the dimensionless

exciting force decreases as the valve opening increases,

see Fig.5. For small valve opening values, a littlechange in the plug position yields to a significant

variation in the value of the exciting force whichmeans that the effectiveness of valve position becomes

very much pronounced for small values of valveopening. Based on the experimental results an

approximating equation may be obtained as follows,

41356.1Qlog109049.0F dd (4)

Formula (4) was established with the least-square-error technique of fit using the experimental data, and

automated curve fitting software.

Fig. 4. The variation of the dimensionless exciting

force with the dimensionless volume flow rate

V. Experimental Uncertainty

Experimental uncertainty in the present work has

several sources. The most obvious and easiest toquantify is the error associated with the

instrumentation. This includes the pressure transducers,the orifice flow meter, and load cell. The uncertainty

for pressure measurements was 1.0 percent. The

flow meter had an error of one percent of the reading.

The load cell had an error of 5.0 percent. Other

sources of error in the study included the plug percentopening and the errors caused by plug centering. The plug percent opening error was investigated

experimentally using repeated measurements and

applying statistical arguments. The measurements weretaken using a dial indicator that gave an error of one

percent of the valve percent opening. The uncertainty

associated with plug percent opening error wasnegligibly small. Centering the plug with equally

spaced was investigated. This was verifiedexperimentally by rotating the valve stem after the

setting of the valve opening, while takingmeasurements in the load cell. The results showed that

the flow force acting on the plug (valve stem) couldvary by a maximum of 4 percent depending on the

valve opening percentage and the plug's rotation. The

experimental uncertainty changed with valve opening.

When calculated as a percent of the measured vC , the

experimental uncertainty ranged from a minimumvalue of 1.66 percent error to a maximum value of 7.21

percent error.



VI. Computational Fluid Dynamics (CFD)

Using FLUENT 6.3, a three dimensional model of the valve body and connecting pipes shown in Fig.6 is

created to investigate the flow. The valve was modeledwith the plug positioned at different percent openings.

The converged flow field was used with Equation (1)

to calculate the valve vC . Also, the converged pressure

was used to calculate the flow net force acting on the

valve stem.

Geometry: The fully dimensioned valve was modeledand the plug and seat region was well represented.

Upstream of the seat, the inlet pipe length divided by

the valve diameter

D

Lwas 5, and downstream of the

seat, the outlet pipe length divided by the valve

diameter was 11.

Grid: The grid used in the numerical study was made

up of tetrahedral cells, the nodes of grid were clusteredin the plug and a seat region since this was the area of

largest flow gradients. In addition, an effort was madeto reduce the grid distortion. Fig 5-a shows an extendedview of the grid and Fig.5-b shows the expanded view

of the grid.

Boundary conditions: All solid boundaries wererepresented as walls with no slip velocity conditions

and log well turbulence conditions. Inlet conditionswere represented by a uniform total pressure. The

treatment of pressure inlet boundary condition can bedescribed as a loss-free transition from stagnation

conditions to the inlet conditions. For incompressibleflows, this is accomplished by application of the

Bernoulli equation at the inlet boundary. The outlet

boundary conditions were set as a uniform static

pressure. The boundary conditions at inlet and outletsections of the domain of solution were obtained fromthe laboratory experiments. Turbulence intensity and

turbulence length scale at the entrance cross section

were set as 81eR 16.0I and hd0175.0L [13],

where hd is the hydraulic diameter. Test cases were

run with 10 and 20 percent turbulence intensity, nosignificant change in the predictions was observed.

Selection of turbulence model: The choice of turbulent model depends on consideration such as the

physics encompassed in the flow, the established practice for a specific class of problem, the level of

accuracy required, the available computational

resources, and the time available for the simulation.Two equation turbulence models have become the

most popular, since they are relatively simple to program and place much lower requirements on

computer resources than other more complex models

(Algebraic and Reynolds stress models). The k

model relates the turbulence viscosity, )sPa(t , the

turbulence kinetic energy, )sm(k 22 , and the

turbulence dissipation rate, )sm( 32 . The k

turbulence model is similar to the low Reynolds

number k model, with replacing , which

represents the specific dissipation rate )s( 1 .

Researchers have developed many turbulence models

provided results with major differences andcontradictions in some cases. The model used in this

study was the two-equation k model. The Standard,

RNG, and Realizable k models are investigated.

Other turbulence models (Standard and Shear Stress

Transport, SST k ) were used in an attempt to

obtain the best convenient model for the present study.

All turbulence models were used with the standard parameters.

Numerical accuracy: All conservation equations are

discretized in FLUENT using a finite volumeformulation with second order spatial accuracy. Thecontinuity is satisfied using a SIMPLE (semi-implicit

pressure linked equations) algorithm. Normalized

residuals were used for the convergence criteria, which

was set at three orders of magnitude.

The numerically tested valve was geometricallysimilar to that applied in the experimental

investigations. It was assumed that the flow is three-dimensional, steady, isothermal, turbulent, Newtonian

and incompressible. However, body forces have beenneglected. Water, at the room temperature, was applied

as the fluid passing through the valve. The flow wasgoverned by the system of mass and momentumconservation equations. In turbulent flow region the

system of equations RANS (Reynolds Averaged

Navier-Stokes equations) was closed by theintroduction of the turbulence model.

Fig. 5. Generated mesh for investigated geometry

(a) Extended view

(b) Close up view of grid



VII. Results and Discussions

The flow field was examined through theinterpretation of the post process data resulting from

the model solution. The results of the numerical studyare shown in Fig.6 through 11, and Fig.13 shows the

comparison of numerical and experimental results of the inherent valve characteristics.

Flow field: The numerically obtained path line patternsin a partially opened valve on the longitudinal mid

plane for 5, 10, 20, 30 and 40 percent openings are

illustrated in Fig.6. On the upstream surface of the plugdisk a stagnation region forms and outside of this

region, the flow direction is towards the edge of the

disk. In each case, the flow initially accelerates throughthe plug and seat region and then flows downstream in

the form of a wall jet at the side of the valve body, andat the open valve side. For valve opening up to

approximately 30%, flow separation from the plug witha second recirculation zone occurs between the wall jet

and the plug surface. At valve opening greater than30%, the results show that the flow remaining attached

to the plug surface, Fig.6-e. In addition, a largerecirculation region develops on the downstream sideof the plug at the closed valve body. As the valve

opening increases, flow separation from the valve body

with a recirculation zone between the jet and valve body at outlet path of the flow occurs. A vena contracta

phenomenon and a hydrodynamic minimum flow areadown stream of the plug are observed. The jet flows

interact and mix downstream of the trim area andsufficiently far from it the flow again occupies the

available flow area and approaches a fully developed pipe flow.

Pressure contours: Fig.7 displays the numerically

modeled contours of the static pressure in a plane

placed close to the upstream surface of the plug. Atsmall opening value, the results show that the pressurecontours are radial relative to valve centerline, which

implies that the pressure field is primarily one

dimensional with the axial (stem) direction. As thevalve percent opening increases, the static pressure

contours become two dimensional and the gradients areless confined to the gap between the plug and seat. In

each case, the pressure decreases in the downstreamdirection with the largest pressure gradients occurring

in the plug and seat region. No significant pressurechanges are observed upstream of the seat and onlyminor changes are observed downstream of the seat.

Fig.8 shows the variation of the static pressure along a

line in a longitudinal mid-plane placed close toupstream surface of the plug. The pressure has a

maximum value corresponding to zero total velocity at

stagnant point, see Fig.9. At the plug edge the static

pressure has a minimum value while the velocity of thefluid has a maximum value.

Fig. 6. Numerically obtained path line patterns

in a partially open valve.



(a)

(b)

(c)

Fig. 7. Pressure contours at upstream plug surface.

(a) 5% opening

(b) 20% opening

(c) 40% opening

(a)

(b)

(c)

Fig. 8. Pressure distributions at upstream plug surface

(a) 5% opening

(b) 20% opening

(c) 40% opening



(a)

(b)

(c)

Fig. 9. Velocity distributions at upstream plugsurface.

(a) 5% opening , (b) 20% opening

(c) 40% opening

Fig. 11. Comparison of flow forces for different

turbulent models.

(a)

(b)

(c)

Fig. 10. Turbulent Kinetic Energy contours.( K-ω Turbulence Model.)

(a) 5% opening, (b) 20 % opening

(c) 40% opening

Fig. 12. Comparison between experimental an

theoretical (CFD) values of flow force.



Turbulent kinetic energy: The constant contours for

turbulence energy are shown in Fig.10. The separatedregions of the flow where shear layers exist have the

highest magnitudes of the turbulence kinetic energy 'k'.

The magnitude of the turbulence kinetic energy in the plug and seat region of the valve is high, this is due to

creation of large shear layer as the flow is squeezedthrough this region.

Exciting force: The fluid flow forces acting on the

valve stem were obtained using different turbulentmodels, as shown in Fig.11. It was noticed that no odd

discrepancy neither in the pattern nor the values of theflow forces, for all investigated openings. Moreover,

the flow forces, computed by the k (SST) model

for different valve's openings (5-40 %), have the less

percent of deviation with experimental results,compared with other turbulent models. Fig.12 shows

the comparison between the experimental results andthe numerical results. The maximum percentage of

deviation was 12.81% at 40% valve opening.

VII. Conclusions

Under completion of the study, the followingconclusions are withdrawn,

1- The flow field was examined and the results showthat the valve geometry has a significant impact on

the turbulent flow passing through the valve. The

results are in good agreement with those obtained

by many researchers as pointed in [7] and [15].2- Under the partial opening (greater than 5 %)

condition, a complex three-dimensional (3D) flow

structure set up in the valve region leading to high pressure variations in the valve trim region.

3- The fluid flow forces that acting on the plug and

stem depends on the valve opening percentage. It

was found that the smaller valve opening, the larger the exciting force acting on the valve stem. Theharmful effect of the fluid flow forces (exciting

forces) is very much pronounced at relativelysmaller valve opening.

4- The simulation results for turbulent flow with

k model were more accurate than the k

model. Moreover, k model was simpler and

faster in convergence than the k model. These

results are in agreement with those obtained by [10].

References

[1] Miller,H.,1998, "Control Valve Applications", Chapter12,

Control Valves: Practical Guides for Measurement and control.G.Bordon, Editor, ISA Press, Research Triangle, North

Carolina

[2] Miller H., and Stratton L., 1997, " Fluid Kinetic Enrgy as a

Selecti on Criteri a for Control Valves", ASME Fluids

Engineering Division Summer Meeting.

[3] Hardin J., Kushner F. and Koester F., 2003, "Elimination of

Flow-Induced Instability From Steam Turbine ControlValves", Proceeding of the Thirty-Two Turbomachinery

Symposium.

[4] Wojtkowiak J., and Oleśkowicz-Popiel C,.2006,"Investi gations

of Butterlfly Control Valve Characteristics", Foundations of

Civil and Environmental Engineering, V.7, ISSN 1642-9303

[5] Kim R. H., and Huang C., 1993, "3-D Analysis Butterfly

Valve Fluid Flow", Proceeding of the Korean Fluent User's

Group Meeting, Seoul, pp 43-57.

[6] Chern M., and Wang C., 2004, " Control of Volumetric Flow-

Rate of Ball Valve Using V-Port", Trans ASME J. of Fluids

Engineering, Vol. 126, pp: 471-481.

[7] Davis J., and Stewart M., 2002," Predic ting Control Valve

Performance-Part I: CFD Modeling", Trans ASME J. of Fluids

Engineering, Vol. 124, pp: 772-777.[8] Hong G., Xin F., and Huayong Y., 2000, "Numerical

Simulation Of Cavitating Flow In Hydraulic Conical Valve" ,

A project supported by SRF for ROCS, SEM and National Natural Science Foundation of China (59835160).

[9] Amirante R., Del Vescovo G., and Lippolis A., 2006, "

Evaluation of the Flow Forces on an open Center DirectionalControl Valve by means of a Computational Fluid Dynamic

Analysis", Journal of Energy Conservation & Management,

Vol. 47,pp:1748-1760.

[10] Oza, A., Ghosh, S., and Chowdhury, K.,2007," CFD Modelingof Globe Valves for Oxygen Application", Proceeding of the

16th Australasian Fluid Mechanics Conference.

[11] Au-Yang MK, Jordan KB, Nucl Eng Dec.1980,"Dynamic pressure inside a PWR-a study based on laboratory and field

test data", Vol. 58, pp:113-125.

[12] Research Triangle Park, North Carolina: Instrument Society of America., ISA-S75.01-1997, "Control Valve Sizing

Equations",

[13] Fluent 6.3 User's Guide, Fluent Inc. 2005.

[14] Launder B. E. and Spalding D. B., 1972,"Mathematical

Models of Turbulence", London, Academic Press.

[15] Bernard, S., Muntean, S., Susan-Resiga, R. and Anton, L.,

2005, " Vorticity in Hydraulic Power Equipment", Proceedings

of the Workshop on Vortex Dominated Flows, Achievements

and Open Problems, Timisora-Romania.

Acknowledgements

The authors want to express their great thanks and sincere gratitude

for both Prof. Zakria Ghoneim (Mechanical Engineering Department,

Faculty of Engineering, Ain Shams University) and Prof. El-Sayed

Saber (Mechanical Engineering Department, College of Engineering,

AASTMT) for their continuous guidance and help during theexecution of the present research work.

Authors’ information 1Amr Hassan was birthed on 21-07-1966. A

master degree in mechanical engineering was

obtained in 1994 from faculty of engineering,Alexandria University – Egypt. A PhD was

obtained in 2002 from School of Mechanical,

Materials, Manufacturing Engineering andManagement, University of Nottingham,

Nottingham, UK.

He conducted previous research studies in the fields of windshield

defrosting and demisting in automotive. He is now interested in the

using computational fluid dynamics in flow simulation.

Dr. Amr is member of Society of Automotive Engineers, SAE and

IMarEST (The Institute of Marine Engineering, Science and

Technology)

2Ashraf Sharara was birthed on 05-01-1970.

A master degree in mechanical engineering

was obtained in 1997 from faculty of

engineering, Alexandria University – Egypt.

Currently , a PhD student at faculty of

engineering, Ain Shams University – Egypt.

He conducted previous research studies in the fields of applied

mechanics. He is now interested in studying the phenomenon of flow

induced vibration in fluid valves.

Documents

5965_48_40_a Study of Turbulence Induced Forces Acting on the Blobe Valve_2005