Fluid Mechanics Projects

A NOTE ON THESE PROJECTS

Most projects I offer involve one (or sometimes more) of

1. Computational Fluid Dynamics (CFD) 2. Some level of programming in either

MATLAB or a proper programming language

3. Use of the Linux operating system In the past, none of my projects has been too difficult for the students that have taken them, so do NOT be put off if you don’t currently have these skills. However be prepared to have to put a concerted effort into learning them during the early part of the project. All projects do assume some knowledge of fluid mechanics, a good mathematical ability, a degree of physical intuition and a strong desire to learn and apply new skills. They are all 12 Credit Point projects and some have 2 titles – the first is the application, the second is the underlying fluid mechanics that are involved.

1)   Wave   damping   using   porous   plates                              (OR  Flow  through  an  orifice  plate)  

(1 project, 12 CP)

The flow through an isolated hole in a plate (usually termed an orifice plate) has applications in a wide range of industrial situations. The study here is motivated by the use of porous plates as partial wave barriers to reduce the impact of waves on coastal infrastructure. When flow impacts a porous plate the pressure drop (and energy required to drive the flow) have been studied previously and can be related to the porosity and Reynolds number of the pore size. However, how the nature of the upstream flow (laminar or turbulent) affects this pressure drop (and flow structure) has not been studied in any detail previously.

In this project, CFD (in particular the SEM code semtex developed by Prof Hugh

Blackburn) will be used to simulate the 3D flow of fluid through a single hole in a solid plate to investigate the effect of orifice plate size and upstream flow type. This project will be an adjunct to the work started by an FYP student in 2016. This project would best suit a student who has some experience with CFD and mesh generation already (although it is not essential).

2)  Jet  turbine  blade  cooling              (OR  Vorticity  in  the  Jet  in  Cross-­‐Flow)  

(1 student 12 CP)

The jet in Cross-Flow is a problem that has received significant attention over the last 20 years. It is utilized in dilution or primary air jet injection in gas turbine combustors, to accomplish mixture ratio and NOx control as well as turbine hot section cooling; in film cooling of turbine blades; in primary fuel injection in high speed air breathing engines; and in thrust vector control for missiles and other high speed vehicles.

Figure: Experimental image of a JICF showing details of unsteady structure arising in the flow.

In this project we will utilise CFD to investigate the evolution of vorticity in this flow that occurs as the vortex rings that make up the incoming jet interact with the vortex lines that are advected downstream in the cross flow boundary layer. We aim to answer the question, “Is the horseshoe vortex seen in experiments real or just an artefact of flow visualisation”. This project will continue on from a successful FYP in 2016-17 and would

Fluid Mechanics Projects

suit a student with a good background in fluid mechanics and numerical methods. Experience with the Linux operating system is an advantage and if not a current skill, a willingness to learn is essential.

3)  Mining  waste  disposal  1              (Particle  settling  in  sheared  fluids)  

(1 project 12 CP)

Non-Newtonian fluids are one in which the stress in a flow is not equal to a constant viscosity multiplied by the fluid strain rate. Non-Newtonian fluids abound in nature and in some important applications, these fluids contain large solid particles that are able to settle. The question of how fast particles are able to settle is complicated by the fact that the viscosity depends on the fluid shear. In this project, the student will build on the research of a Ph.D. student and investigate how applied shear modifies the settling rate of spherical particles in both Newtonian and non-Newtonian fluids. Determining the onset of flow separation and transition to unsteady flow will be a key part of this study.

Figure: Streamlines around a spinning particle in a power-law fluid

This project would suit a student with a good background in fluid mechanics and numerical methods. It will be undertaken using the CFD package OpenFOAM. Experience with the Linux operating system is an advantage and if not a current skill, a willingness to learn is essential.

4) Turbulence structure in a swirling container

(1 student, 12 Credit Points)

The swirling flow in a cylindrical container has application in a very wide range of industrial processes including mixing vessels, hydrocyclones, precipitators and in vessels used in brewing beer. This project is motivated by the last application in which the “whirlpool” process is used to separate fine particulate matter from the brew kettle prior to fermentation.

In modelling currently being undertaken in an FYP, a question arose regarding when this flow transitions from laminar to turbulent. This is the question we hope to answer in this project using the SEM code semtex. This project would suit a student with a good background in fluid mechanics and numerical methods. Experience with the Linux operating system is an advantage and if not a current skill, a willingness to learn is essential.

Figure: Schematic of the whirlpool flow (left) and photo of the trub cone (right) in a kettle.

Fluid Mechanics Projects

FLUID CHAOS PROJECTS Chaos is a term commonly viewed as equivalent to disorder or randomness. However, in fluids the common understanding is often incorrect! Chaotic advection produces structures in fluids that can be highly ordered – but not simple. Chaos in fluids is pervasive and generates the template on which all heat, mass and reactive transport occurs. One of the fascinating aspects of fluid chaos is that it can occur in flows that are known exactly in space and time.

5) A novel reactor design (Chaos in Taylor-Couette Flow)

(1 student, 12 Credit Points)

The flow between two rotating cylinders is known as Taylor-Couette flow. On first sight this flow might seem rather bland, but over twenty different flow types have been categorised, each with unique properties. Couette, Taylor-vortex, wavy vortex, modulated vortex, twist vortex, wavy-inflow, wavy-outflow, turbulent vortex, featureless turbulence ..... the list goes on.

Figure: Non-mixing vortex cores in wavy vortex flow (green and blue structures), encircled by inclined non-mixing rings (yellow structures).

In this project, the student will use an advanced CFD code to study some of these Taylor-Couette flow regimes in detail and apply Lagrangian particle tracking to understand which might give rise to chaotic fluid flow. In particular, “twist”, “wavy inflow” and “wavy outflow” flow regimes hold promise for

dividing the flow into “reaction units” that do not mix with each other, but which mix well internally. The students will develop an appreciation for supercomputing and the use of sophisticated computer codes to understand the real world.

The project is computationally based, and will suit students with a strong interest in fluid mechanics and numerical methods. It will continue a project started in 2016.

6) Experimental chaos

(1 student, 12 Credit Points)

Visualisation of chaotic flows has produced many beautiful flow images that also offer detailed insight into flow structure and mixing processes.

In this project, a new experimental apparatus that has been designed and partially built in the Monash Engineering workshop will be completed and commissioned with significant input from the student. Once operational, a series of flow visualisations will be undertaken. It will follow on (and potentially overlap) with a current FYP project and would suit a student with good mechanical skills and an interest in experimental fluid mechanics. A knowledge of electronics would be an advantage, but is not essential.

Figure: Mixing/segregation in a stirred tank. Top is the attractor vortex that draws particles into a torus near the impellor and bottom is a visualization of invariant surfaces and manifolds.