Download Research Projects List 0405

Postgraduate Opportunities
at M.Eng.Sc. & Ph.D. level
2004/2005
Department of Mechanical Engineering
Applicants should contact the relevant supervisor (contact details given
inside) before proceeding further with their application.
Application forms for both M.Eng.Sc. and Ph.D. projects can be obtained
from the department office or downloaded from the departmental website
(www.ucd.ie/~mecheng).
Department of Mechanical Engineering
Room 226
Engineering Building
University College Dublin
Belfield
Dublin 4
Tel: ++353 (0) 1 716 1884/1787
Fax: ++353 (0) 1 283 0534
Email: [email protected]
Web: www.ucd.ie/~mecheng
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Supervisor:
Eamonn Ambrose
(National Institute of Technology Management)
Modeling and Simulation of the Supply Chain
While simulation of manufacturing operations has received a lot of academic and
industry attention, the modelling of supply chains has, up until recently, been
relatively neglected. With the advent of globally distributed operations with
substantial outsourcing, the understanding and management of complex supply
chains and networks is becoming increasingly important. This area is of
particular interest to Irish industry, as we attempt to replace our manufacturing
industries by ‘moving up the value chain’ to higher added value operations. The
NITM are currently working with a number of indigenous and multinational
companies on the application of modelling and simulation software to the
complete supply chain. A number of opportunities exist at MSc level and
possibly at PhD level. These include both technology-oriented studies of the
tools used for modelling and simulation, and management-oriented work on
business process improvement strategy and implementation.
No funding is available at present, but applications are under consideration.
Contact Details:
Room 205, Engineering Building
Ph: ++353 1 716 1741
Email: [email protected]
Supervisor:
Dr. David Browne
Controlled Flow and Nucleation in Terrestrial Alloy Solidification
Metallic solidification microstructure is determined by the nucleation, growth and
advection of crystals during freezing of the alloy. Suppression of the influential
natural liquid convection can be achieved in microgravity conditions. However,
such microgravity studies have to date been limited to 1D directional
solidification. It is proposed to develop a unique universal 3D solidification
device, in which shaped components can be cast under controlled convective
conditions, on earth. The project will inspire a future experimental campaign in
space. The project, if funded, will support a full 3-year PhD studentship plus the
requisite equipment and materials for the experiments.
Contact Details:
26th March 2004
Room 306, Engineering Building,
Ph: ++353 1 716 1901
Email: [email protected]
2
Supervisor:
Professor Gerald Byrne
1. Chemical Mechanical Planarisation Study
This program investigates chemo-mechanical surface modification processes for
the
manufacture
of
future
miniaturized
microelectronics
and
microelectromechanical (MEMS) devices. The goal of the research is to
generate a set of process and machine design rules, and process monitoring and
control strategies, that enable the implementation of high productivity processes
to meet the requirements of the microelectronics and MEMs industries for the
next two decades as they scale further into nano-scale dimensions. The
methodology includes:
 a theory and modelling activity that will provide a fundamental understanding
of the surface modification processes
 an experimental activity to test novel consumable tool performance on a
range of important materials and structures, and
 a process monitoring and control activity to develop process and tool
sensitive sensors and understand how they can be best integrated into the
manufacturing process.
The work will place an emphasis on fixed abrasive pads but other novel
techniques will be investigated. This programme will provide opportunities for
graduates who wish to pursue a masters or PhD qualification by research into
the core manufacturing processes of the semiconductor industry. This project
will involve networking with international centres of excellence and global
manufacturing organisations. The project is sponsored by Intel with a decision
on other sources of funding pending.
2. Surface Generation Mechanisms in Ultra-Precision Finishing of Silicon
In the production of integrated circuits, the surface of the silicon substrate
must conform with a planarity specification of sub-micron order ( over a
die area of 27*27 mm ) and surface finish of less than one nanometer Ra
( roughness arithmetic average ). Other surface finish requirements also apply
relating to sub-surface damage and material parameters. With developments
such as higher component densities and increasing diameters of silicon substrate
(200 to 300 mm), the specified tolerance ranges are reducing and demands on
the capability of current production processes are increasing. The process of
interest here is the so called “ultrprecision process” consisting of micro and nano
surface grinding operations followed by polishing.
The proposed programme will consider recent research into the fundamental
phenomena in fixed abrasive finishing (grinding) of silicon with particular reference
to the effect of process parameters on the ductile-brittle transition. Recent
technological developments in relation to the total machine system will also be
appraised including: high loop stiffness, machine structures with high dynamic
damping and ultra-precision control systems. The grinding tool parameters are
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also to be considered with a view to developing and testing ultra-precision
specifications in collaboration with the sponsor. The ultimate objective is to define
a practicable process, tool and machine specification to extend the performance
limits of current technology. Improvement in surface finish will reduce the
required level of subsequent polishing or potentially eliminate this operation.
This programme will provide opportunities for graduates who wish to pursue a
masters or PhD qualification by research in the core manufacturing technologies of
the semiconductor industry. A decision on funding of this project is pending.
3. Coating deposition using atmospheric plasmas
Surface Engineering involves the use of plasma treatments for coating deposition
and surface activation. With these treatments, the properties of surfaces can be
tailored or engineered for a given application. This technology has become a
standard tool for the engineering of a wide range of surfaces, including those of
medical devices, tooling electronic and optical components. The Surface
Engineering Research activity together with Dow Corning Plasma Solutions have
set up a joint research project which has been funded under the Innovation
Partnership Program. The project will investigate the deposition of hydrophobic
and hydrophilic coatings on polymer sheets using the atmospheric pressure
plasma systems being developed by the company. Specifically the company is
interested in enhancing the barrier properties of its coatings. Barrier properties
are critically important in packaging, for example for foodstuffs and
pharmaceuticals, there are also developing applications in electronics and
flexible displays. Barrier to oxygen and water vapour are critical needs in these
applications. The research work will involve a study of the influence of deposition
conditions on coating properties. The deposited coatings will be characterised by
measuring their surface energy (contact angle measurement), morphology
(optical profilometry, SEM), wear resistance, friction and adhesion. Dow Corning
will assist the research work by carrying out XPS and gas barrier measurements
at its plant in Cork. This funded project is suitable for candidates who wish to
pursue a M.Eng.Sc. degree.
Co: Supervisor: Dr. Denis Dowling
4. Examination of the influence of implant surfaces on cellular response
The study of cell-biomaterial interactions is primarily centred around two
inextricably linked areas of investigation: the nature of the biomaterial surface
and the biological response to contact with the material. Biomaterials interact
with the biological environment at their surface, making accurate biophysical
characterisation of the surface crucially important for understanding subsequent
biological effects. In this project the surfaces of silicone and polyurethane, will be
systematically modified using plasma treatments / coatings to achieve water
contact angles in the range 10° to 160°. The properties of the treated surfaces
will be examined to determine their surface energy (contact angle), roughness
and morphology. The interaction of cells with the treated surfaces will also be
examined using DNA microarray-based gene expression profiling techniques, in
conjunction with cellular phenotypic analysis. The latter study will be carried out
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in conjunction will colleagues in the Conway Centre. This research should
provide a fundamental understanding of the influence of implant surface
properties on human cell adhesion and associated cellular responses. It will be
the first study of this type involving a full range of surface energies. This
programme will provide the opportunity for a graduate who wishes to pursue a
PhD qualification by research in an import area for the biomaterials industry. A
decision on funding is pending under the Basic Research Grant Programme.
Co: Supervisor: Dr. Denis Dowling
5. Fine Grinding Technology
Grinding is a key enabling technology for a range of manufacturing industries in
Ireland, including precision engineering, aerospace, medical devices, crystal
glassware and electronics. For these industries achieving a high surface finish
makes an enormous difference to properties, which are application dependent,
but range from enhanced mechanical performance and energy efficiency to
visual appearance and reduced component wear. Lapping is one of the most
commonly used grinding techniques applied in these industries. The alternative
employs a tool with a solid matrix of diamond or cubic boron nitride (CBN)
abrasive particles in a metal, ceramic (vitrified) or resin bond. This grinding
process uses very little oil, is very reproducible due to the low wear rate and
hardness of the super abrasives and is generally 10 times faster than lapping.
This project will focus on developing the fixed super abrasive grinding process
and will examine issues influencing grinding efficiency e.g. super abrasive
particle size, metal bond composition and strength etc. Grinding tests will be
carried out on steel and glass substrates. These tests will initially be carried out
in the laboratory and subsequently in conjunction with end users in the crystal
glass and tool making industries. This project is suitable for candidates who wish
to pursue a M.Eng.Sc. degree. A decision on funding is pending under the
Commercialisation Fund.
Co: Supervisor: Dr. Denis Dowling
Contact Details:
Room 225, Engineering Building
Ph: ++353 1 716 1883
Email: [email protected]
Supervisor:
Dr. Donal Finn
Design Optimisation of Thermo-Electric/Thermo-Acoustic/Magnetic/Stirling
Refrigeration Technologies in Water Cooler Systems
As the twin issues of ozone depletion and global warming continue to influence
global policy makers, refrigeration manufacturers are beginning to show interest
in alternative refrigeration technologies to the vapour compression cycle.
Emerging technologies of interest are based on concepts such as thermoelectric
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cooling, thermo-acoustic cooling, thermomagnetic refrigeration and stirling cycle
refrigeration. The aim of this project, which is sponsored by Oasis, a
manufacturer of office water coolers, is to design and optimise a refrigeration
system for an office water cooling device (100W) using one of these emerging
technologies. The specific objectives are (i) design and construction of a
prototype system, (ii) development of a simple thermodynamic model, (iii) testing
and optimisation, (iv) production cost analysis. this project will be funded, is both
innovative and practical, and by being closely linked with an industrial company
will provide good exposure to a variety of practical engineering issues.
Industrial Link: Oasis Ltd (www.oasiswatercoolers.com)
Contact Details:
Room 311, Engineering Building
Ph: ++353 1 716 1947
Email: [email protected]
Supervisor: Dr. David FitzPatrick
1. Biomechanics of the Intervertebral Disc (PhD)
The intervertebral disc (IVD) has been implicated in the initiation and progression
of adolescent scoliotic deformity. Current research has developed an analytical
model that suggests a mechanism that is responsible for this initiation and
progression. Additional work is required to fully characterise and analyse the
performance of the IVD in terms of its structure, composition and mechanical
function. While significant work has been carried out in this field by international
researchers, the specific approach taken by this project is highly novel and,
potentially, of great clinical significance. The project will be carried on in
collaboration with local orthopaedic surgeons and other medical/life science
specialists.
Funding: Grant application pending.
2. Application of Shape Analysis Methods to Scoliosis Curvature
Monitoring (MEngSc/PhD)
Previous research has attempted to correlate the surface form of a deformed
spine, as measure by light based scanning techniques, with the severity of the
underlying deformity. The proposed project will attempt to provide a more robust
analysis of the same problem through the application of highly novel shape
analysis tools to the surface scanned data. It is anticipated that this will provide a
level of detail and quality of information that is significantly better than anything
previously proposed and will result in a clinically useful and applicable tool.
Funding: Grant application pending.
3. Other Project Areas:
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Other candidate projects exist in the field of veterinary biomechanics, spinal
biomechanics and shape analysis methods. If interested, please contact Dr.
FitzPatrick directly.
Contact Details:
Room 220, Engineering Building
Ph: ++353 1 716 1829
Email: [email protected]
Supervisor: Professor Michael Gilchrist
1.
Development of Traumatic Brain Impact Injury Criteria
The objective of this funded PhD project is to quantify the mechanical strains and
stresses that are induced in brain tissue by the action of linear and rotational
accelerations associated with different impact events.
3D computational
mechanics techniques will be used to model a parallel set of clinical impact tests
(separate project). The overall aim of this collaborative research is to use both
biochemical and mechanical measures of tissue damage resulting from specific
levels of impact to develop threshold injury criteria, which can be used to
establish whether particular brain injury lesions (e.g., contusion, diffuse axonal
injury, or haematoma) would or would not occur because of a particular impact
event. These results will be uniquely important for the clinical treatment and
management of head injured patients, and for the engineering design of
protective devices.
2.
Anthropometric Finite Element Head Models: Automated Generation
and Use of Patient-Specific 3D Finite Element Meshes
The objective of this funded PhD project is to develop a novel method for
automatically constructing three-dimensional finite element models of the human
head. Such a methodology could ultimately be used to construct models of other
biological organs, limbs and structures for subsequent bioengineering analysis.
The challenge of this particular project lies in the need to accurately represent
appropriate geometric and material irregularities in various biological entities: this
involves distinguishing between different materials (e.g., fluid, tissue, bone, etc.)
and in representing these differences in a numerically efficient finite element
model. The method to be developed must identify suitable anthropometric
markers, which will form the basis of morphing a generic finite element model.
The models that are so generated in this project will be used to analyse patientspecific head impact accidents and to predict the associated injuries. This project
will involve collaborative interaction with other research groups in Europe and
USA.
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Contact Details:
Room 310, Engineering Building
Ph: ++353 1 716 1890
Email: [email protected]
Supervisor:
1.
Donal Hughes
Industrial Technological Requirements for the Design and
Production of Micro-scale Miniaturised Components
The use of micro products and components has increased significantly in the
past decade and is now a major global industry. Engineering systems in general
are reducing in weight and in many cases in physical size. This trend is being
driven by the necessity to reduce energy utilisation levels and new applications,
for example in IT components and medical and biomedical products. Apart from
the development of new and innovative applications such developments will have
a significant contribution towards the achievement of the KYOTO protocol
objectives. In the Irish context, the success of internationally trading SMEs will
depend on their ability to deal with the geographic and infrastructure boundary
conditions prevailing in Ireland. A number of issues which can be identified
include: increased level of design, high value added components/systems, small
physical sized components, agility in design and manufacture, components which
can be easily packaged and exported. Hence high value-added, innovative,
microengineered products are of high economic importance. An analysis of the
sectoral technological requirements for indigenous industry and how those
requirements can best be meet forms the core of this project. The successful
student will be operate as part of a recently established PREMI team within the
AMT/MI Research Centre and will be expected to network with indigenous
industry and our European partners. Funding for this project has been secured
via the European Union INTERREG III B program under the project ‘Partnership
in Sustainable Development through Product Recyclability, Miniaturisation, and
Production Waste Reduction’.
2.
Manufacturing Technologies for the Production of Miniaturised
Components for the Medical Devices Industry
The use of new engineering materials coupled with the reduction in component
physical dimension places entirely new demands on the manufacturing
processes. New manufacturing systems have to be developed for each stage of
the process and a higher level of understanding of the underlying fundamental
mechanisms through modelling and simulation is required. The surface
properties have to be engineered and not just left to dictation by the
manufacturing process and its variables. This work will examine the state of the
art in manufacturing technologies for the production of miniaturised components
for the Medical Devices industry in Ireland. The successful student will be
operate as part of a recently established PREMI team within the AMT/MI
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Research Centre and will be expected to network with indigenous industry and
our European partners. Funding for this project has been secured via the
European Union INTERREG III B program under the project ‘Partnership in
Sustainable Development through Product Recyclability, Miniaturisation, and
Production Waste Reduction’.
Contact Details:
Room 209, Engineering Building
Ph: ++353 1 716 1725
Email: [email protected]
Supervisor:
1.
Professor Alojz Ivankovic
Characterisation of CZM Properties in PE (M.Eng.Sc.)
The failure of the craze structure ahead of the crack tip controls the onset of the
slow crack growth process in tough pipe grades polyethylene. An experimental
procedure has been developed to analyse this craze structure employing a
circumferentially deep-notched tensile (CDNT) specimen. Cohesive zone model
or traction separation (TS) curve is used to explain the fracture process.
Measurements over a wide range of loading speeds with different geometries
have been performed. It has been showed that the parameters governing the TS
curve are both rate and constraint dependent.
Here, experimental work will be extended to examine the effect of constraint on
the TS behaviour. In particular, recently developed ‘stop-section’ technique will
be employed, where the test is stopped at a pre-determined load. The specimen
is then sectioned and the craze analysed using SEM. This allows the
examination of the damage evolution.
Aims
1)
To conduct stop-section CDNT tests under varying constraint conditions.
2)
To examine the evolution and craze structure under different constraint
conditions.
3)
To compare findings for different PE grades.
The project will appeal to a student with an interest in material properties taking
Polymers, Stress Analysis, Fracture or equivalent courses, and with practical
engineering skills.
Associate Supervisor: Neal Murphy
2.
Construction of a Surrogate human lung (M.Eng.Sc.)
Blunt injuries to the upper torso or thorax are a major cause of overall mortality
and morbidity following injury. Blunt injury to the thorax can be caused by a
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number of physical forces, the most common of which follow automobile
accidents.
Physical models are used in impact experiments in order to better understand the
human body dynamic response to various impact loads and also to measure the
injury risk to various body regions. These models are either used to test for
crashworthiness of a component or vehicle; but also in the tests used to check
the integrity of blast armour protection suits used by the military and police.
An area of particular interest has been in developing a model of the dynamic
response of the human lungs to high rate impacts since they are more
susceptible to damage than the other organs in the human thoracic region.
The current methods include the use of a combination of lungs from live animals
and artificial models. In order to reduce or possibly eliminate the use of live
animals for such experiments the development of a surrogate artificial lung is
required. The human lung is viewed to exhibit the mechanical properties similar
to that of a soft ‘spongy’ polymeric material (foam). A range of concepts have
been proposed for the construction of this surrogate lung ranging from the use of
simple polymeric foams to plastic ‘bubble wrap’, but the use of fluid filled microspheres embedded into a foam matrix seems most encouraging.
Aim
The main aim is to develop a physical human lung model that will describe its
dynamic response (motion, deformation, damage, …) under various loading
conditions more so under high impact rates. This model must fulfil the following
criteria:
1. The model should exhibit similar stress wave properties as that of a real
lung;
2. It should be able to reproduce in a qualitative manner the damage
resulting from impact.
The project will appeal to a student with an interest in material properties taking
Polymers, Stress Analysis, Fracture or equivalent courses, and with practical
engineering skills.
Associate Supervisor: Dr. A. J. Carr
3.
High Rate impact: gas-gun development and testing (M.Eng.Sc.)
There is a large and ever growing interest in the behaviour of materials under
impact loading ranging from tens to hundreds of metres per second. Various
industries, such as transport, space, military, medical, etc., are interested in the
high-rate impact (including ballistic) studies. We have expertise in high rate
testing and modelling of polymers, composites, adhesives, metals, etc.
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Our existing gas-gun is in need of modernisation. It can currently ‘fire’ large
projectiles (of the order of a kg in mass) at a maximum speed of 20 m/s. This
max. speed can be increased by reducing the mass (or redesigning) the
projectile and/or by redesigning the rig.
The proposed project is of a practical nature and much of the work is required to
improve the existing rig. Also, some initial experiments will be conducted on a
range of materials at a range of impact speeds.
Aims
1)
To improve/redesign the gas-gun in order to increase the projectile speed
from current 20 m/s to ~200 m/s.
2)
To improve/redesign pressure control system.
3)
To improve/redesign projectile speed measuring device.
4)
To conduct high impact pilot tests on a number of materials and at a range
of speeds.
The project will appeal to a student with an interest in materials and with practical
engineering skills.
Associate Supervisors: Professor D. Moore, Professor M. Gilchrist
4.
Towards Early Diagnosis of Atherosclerosis (Ph.D).
Atherosclerosis is a disease of the large arteries involving local accumulation of
lipids, calcium and proliferating cells within arterial walls. These lesions can lead
to a blockage of an artery and a failure of perfusion; in coronary arteries it causes
heart attacks, in cerebral arteries, stroke.
Risk factors such as gender, obesity, smoking, cholesterol, and family history,
affect the whole cardiovascular system but cannot explain the highly local nature
of atherosclerotic lesions. The 'low shear' hypothesis postulates that lesions form
at locations where the wall shear stress is low. This hypothesis is supported by a
wide range of studies correlating the locations of lesions and the distribution of
wall shear stress. Virtually every function of the cells is affected by the shear
stress caused by flow of blood. It affects cell shape, gene expression, the
functioning of membrane receptors and channels, etc.
The search for in vivo mechanisms relating wall shear stress and atherogenesis
is severely hampered by the impossibility of measuring wall shear stress directly.
Our knowledge about the distribution of wall shear stress is based upon the
extrapolation of measurements in in vitro models, computed from theoretical
calculations in model arteries, or, more recently, from CFD calculations based
upon in vivo measurements made with MR or ultrasound. With very few
exceptions, the in vitro and theoretical models have been for rigid walls. Since
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arteries are elastic, the extrapolation of experimental or computational results to
the arteries is still very problematic.
Aims
We propose to develop solid-fluid interaction model based on Finite Volume
discretisation for predicting behaviour of distensible tubing under pulsatile
pressure. Experimental rigs will be built from single and branched rubber tubes.
Tubes will be connected to water tanks and pumps and subjected to steady and
unsteady driving pressures. To simulate the initial stages of atherosclerosis
regions of tubings will be stiffened by applying an additional layer of the same
material. The deformation of the tubes and water flow will be measured. The
numerical model will simulate the experiments with particular emphasis on
predicting the deformations around the thickened regions.
Our main aim is to explore a novel approach for diagnosing the signs of early
atherosclerosis. Instead of concentrating on flow patterns, as the majority of
workers in the area do, we propose to concentrate on wall deformation patterns.
The reason being that the flow is noticeably affected only at very late stages in
the development of atherosclerosis, when more than 50% of arterial cross
section is blocked by fatty deposition (plaque), forming a stenosis. As a result of
the complex interaction between the flowing blood and the deforming arteries,
the presence of a stiffened region in the arterial wall, which is believed to be the
first key stage in the development of the disease, was found to have a
pronounced effect on the deformation profile.
Associate Supervisor: Dr. Malachy O’Rourke
5.
Characterisation of CZM Properties in Adhesives (M.Eng.Sc.)
The Cohesive Zone Model gives the relationship between the tractions holding
the two separating fracture surfaces and the separation distance between them.
In most published work however, the parameters of this traction – separation
curve, i.e. the strength of cohesion, the area under the curve representing the
fracture toughness, and indeed the shape of the curve, were assumed. Only in
limited number of studies the calibration of the CZM parameters was achieved by
fitting the numerical predictions to fracture experiment results, or by direct
measurements.
The proposed project aims to examine the validity of employing an experimental
procedure for measurement of CZM curves in structural adhesives. The same
method was successfully used for other polymers such as PE.
DNT test: Circumferentially deep-notched tensile specimens will be employed for
measuring CZM of the adhesive. The idea is that damage and separation
processes will uniformly develop across and be confined within a highly
constrained region of the notch ligament. The geometry of the notch, its depth
and the tip radius, are the most important factors in controlling the test.
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The project will appeal to a student with an interest in material properties taking
Polymers, Metal Technology, Stress Analysis, Fracture or equivalent courses,
and with practical engineering skills
Associate Supervisor: Mr. Neal Murphy
Contact Details:
Room 228, Engineering Building
Ph: ++353 1 716 1994
Email: [email protected]
Supervisor:
1.
Neal Murphy
Dynamic fracture characterisation of PMMA (M.Eng.Sc. only)
Previous work has shown that when SENT specimens of PMMA are loaded to a
critical level, the resulting dynamic fracture behaviour at room temperature
depends on the length of the initial notch and the molecular weight of the
material. Initially, the crack tip accelerates up to an approximately constant mean
terminal velocity, well below the theoretical upper limit as determined from linear
elastic fracture mechanics. The subsequent crack growth is accompanied by
increasing fracture surface roughness, the formation of microbranches and
occasionally macroscopic branching, resulting in fragmentation of the specimens.
In order to characterise the dynamic fracture behaviour of the material, it is
necessary to accurately measure the crack velocity for the duration of the test. It
has been found that the development of subsurface damage is accompanied by
high frequency fluctuations in the crack velocity. It is important to accurately
capture these oscillations to gain insight into the fracture processes taking place
at a microscopic level.
This project aims to set up such an experimental facility in the Department. Initial
investigations have found that an electrical resistance method may be used to
measure the crack velocity, which may exceed 800 m/sec in PMMA. A gold
coating is deposited onto the surface of the specimen and connected to a
potential divider circuit. As the crack propagates, the resistance of the strip
increases and output voltage may be related to the crack length. Suitable
differentiation of the data leads to a crack velocity history.
Aims
1) To design an improved electronic circuit to enable the accurate
determination of the velocity history. This would be undertaken with the
cooperation of the Electronic Engineering Department at UCD and the
Mechanical Engineering Department at Imperial College, London, who
have been performing these tests for several years.
2) To systematically examine the effects of notch length and molecular
weight on the dynamic fracture behaviour.
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3) It may be possible to utilise Acoustic Emission Analysis to characterise the
high frequency fluctuations associated with the subsurface damage.
4) In addition, the behaviour of these materials under impact loading
conditions may be examined.
Co-Supervisor: Professor Alojz Ivankovic
Contact Details:
Room 313, Engineering Building
Ph: ++353 1 716 1940
Email: [email protected]
Supervisor:
1.
Dr. William O’Connor
Waves on Computer
A simple and elegant way of modelling waves on computer has been developed
and is now being extended to a range of interesting problems. Waves come
about when a "disturbance" of some kind can travel, whether on a string, on a
membrane, in water, on air, or even in a vacuum. Many waves obey a standard
wave equation. These are "linear" and are modelled perfectly by the existing
technique. But sometimes the physical nature of the travelling disturbance (such
as a surface wave on water) makes the wave "non-linear" in some way. The
simple model should then be modified to capture this physical effect. The main
aim of this postgraduate project is to get the computer model to mimic the
Physics correctly.
2.
Control of flexible mechanical systems
How do you control the position of a load mass at the far end of a flexible system,
such as a long, light robot arm? If you manage to get the load to the right
position, will it still be shaking? Or, if you manage to stop the vibrations, will the
load have ended up in the right place? (otherwise further movement restarts the
vibration). An approach based on mechanical waves is proving very effective in
combining these two requirements.
Launching a wave does the initial movement, and wave absorption does the
vibration control, but in such a way that everything ends up stationary where you
want it to be. The project would take this work further, using computer simulation
and/or experimental work.
3.
Sensor research
There are a number of on-going projects to develop special-purpose sensors,
including sensors to measure the relative humidity of exhaled air, the density of
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fermenting wine, surface vibration, and counting people.
Contact Details: Room 213, Engineering Building
Ph: ++353 1 716 1887
Email: [email protected]
Supervisor:
Dr. Malachy O’Rourke
The Abdominal Aortic Aneurysm (AAA) is a balloon like bulge that may develop
in the aorta between the renal arteries and the iliac bifurcation. If left untreated
the aneurysm will continue to grow and eventual rupture leads to death in over
90% of patients. The initiation, growth and rupture of the aneurysm are related to
hemodynamic factors, and in particular the interaction of the blood flow with the
inner arterial wall. Blood pressure, coupled with local variations in wall shear
stress and wall shear stress gradient have been cited as important factors in this
regard.
The flow field within the AAA is extremely complex. The flow is pulsatile and may
be in transition depending on the state of rest or exercise of the patient. Blood is
not a simple Newtonian fluid. The aneurysm wall is also deforming continuously
throughout the cardiovascular cycle. As the aneurysm develops the overall
diameter continues to increase. Currently the major criteria for rupture is based
on aneurysm diameter exceeding 5 cm.
Recent work within the Department has examined the nature of flow within the
AAA. Experimental and computational methods have been used to model the
flow within idealised models of rigid aneurysm. Laser Doppler velocimetry (LDV)
and flow visualisation have been used to give important insight into the pulsatile
flow patterns within the AAA. Computational fluid dynamics (CFD) has been
utilised to study in-depth the nature of wall normal (pressure) and shear stresses.
Currently realistic patient based, compliant models are been developed and in
the immediate future work will commence on modelling the flow within. These
models are been developed and manufactured in collaboration with Dartmouth
College, USA.
1.
In Vitro Experimental Analysis of Patient Based Compliant Models
of AAA (Ph.D.)
Mr James McCullough is a PhD student within the Department of Mechanical
Engineering. He is responsible for the development of the patient based,
compliant models and will embark on preliminary experimental modelling in the
near future. The Department has recently acquired funding to purchase a major
upgrade to the LDV system thus enabling instantaneous measurement of two
components of velocity, ideal for measurement of the vortical flows that arise
26th March 2004
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within the aneurysm. The Department is also in the process of seeking funding
for a Doppler ultrasound system, which will enable measurement of wall
deformation.
This PhD will continue the experimental modelling initiated by Mr McCullough. A
study of a number of AAA’s in various stages of development, i.e. increasing
aneurysm diameter will be undertaken. Flow visualisation and LDV
measurements will be made within the aneurysm coupled with Doppler
ultrasound measurements of wall deformation. The evolution of the flow during
aneurysm growth can then be mapped and any major changes in flow identified.
2.
Computational Dynamic Investigation of Patient Based Compliant
Models of AAA (Ph.D.)
In parallel to the ongoing experimental modelling, computational fluid dynamics
has been used to predict the flow field within the rigid AAA models. To date this
work has been undertaken utilising the ANSYS CFX-5 software suite. The
boundary conditions for the numerical model were adopted from the experimental
model, i.e. inlet velocity profile and exit static pressure. Comparison of flow
visualisation studies and LDV measurements show that good qualitative and
quantitative agreement is achievable for the AAA. Solutions have been obtained
for laminar and turbulent flow.
Numerical modelling of patient based compliant models is an exciting challenge.
A new finite volume based, numerical solver will soon be available within the
Department. This code solves the equations of both fluid mechanics and solid
mechanics. The aim of this project is to model the experimental patient based
compliant models in their entirety; the fluid flow within the aneurysm coupled with
the material deformation within the wall.
A number of problems need to be solved: Geometry and mesh generation for
patient based models is by no means straightforward. A model for the nonlinearity of the stress-deformation relationship for the material used in the
experimental model will need to be developed. This will involve experimental
analysis first to determine the material properties and secondly to develop the
stress-deformation relationship. Validation of the code will be made through
comparison with experimental data.
Associate Advisors (both projects): Prof. Alojz Ivankovic and Dr David
FitzPatrick. Funding is currently been sought to support the above proposals.
Contact Details:
26th March 2004
Room 304, Engineering Building
Ph: ++353 1 716 1950
Email: [email protected]
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Supervisor:
1.
Dr. William Smith
Optimisation of intake air flows in a racing engine
The objective of this project is to provide an improved understanding of the intake
air flow in the Formula Student race engine, with the ultimate aim of improving
the performance of the intake system. The Formula Student rules stipulate that
all intake air must pass through a single restrictor no more than 20 mm in
diameter. This restrictor leads to a requirement for a diffusing section, which
must be carefully designed to minimise stagnation pressure losses. Packaging
constraints impose further tight constraints on the format, and physical size, of
the intake system, so obtaining an effective solution is challenging.
The program will use a combination of one-dimensional engine simulations,
computational fluid dynamics (CFX), and experimental engine testing to develop
an improved understanding of the key factors governing system performance. In
particular, an unsteady CFD simulation will be implemented, and the predictions
compared with those obtained from a steady-state case.
2.
An investigation of four-wheel steering (4WS) for a Formula Student
vehicle
The objective of this project is to evaluate the potential of 4WS for improving the
transient response of a Formula Student racing car. An existing vehicle dynamic
model, developed using DADS software, will be used to derive and to evaluate a
variety of strategies for controlling 4WS. One or more of these strategies will
then be implemented using an existing linear actuator with integral PID controller.
3.
Analysis of link forces on a Formula Student suspension system
The objective of this project is to improve our understanding of the magnitude of
tyre forces experienced by a Formula Student vehicle during transient
manoeuvres, and the manner in which those forces are transmitted to the vehicle
chassis. The problem in general is relatively complex, as witnessed by the fact
that even modern Formula One cars have been known to experience suspension
linkage failures. The programme will set out to measure and resolve the tyre and
link forces acting on a Formula Student suspension system in each of the
vertical, horizontal and longitudinal directions, to identify critical manoeuvres, and
to derive a matrix of test conditions that could be used to simulate actual vehicle
operation.
4.
Simulation of link forces on Formula Student suspension systems
This programme is designed to run in parallel with project 3, above, “Analysis of
link forces on a Formula Student suspension system”. The objectives are: to
refine an existing DADS full-vehicle model so that it accurately reflects measured
data; to develop an elastic model of the suspension linkages using DADS and/or
IDEAS, such that the force distribution with the system can be accurately
26th March 2004
17
predicted; and based on the foregoing to develop guidelines for the design of a
generic suspension linkage model appropriate to Formula Student vehicles.
Contact Details:
Room 308, Engineering Building
Ph: ++353 1 716 1901
Email: [email protected]
Supervisor:
Dr. David J. Timoney
Modelling of Steady State and Transient Characteristics of Diesel Exhaust
After-Treatment Systems for NOx and Particulate Matter
Emissions of oxides of nitrogen (NOx) and particulate matter (PM) from light and
heavy duty diesel engines used in transport applications present an
environmental hazard. Progress in recent years has been achieved through incylinder combustion improvements but legislation planned in EU, USA and
elsewhere from 2007/8 will require use of complex exhaust after-treatment
systems for NOx and PM. Viable options envisaged at present include;
(1) Use of Continuously-Regenerating Diesel Particulate Filters (CR-DPF) for
PM removal, and
(2) Application of Selective Catalytic Reduction (SCR) technology for NOx
treatment. This requires that metered amounts of aqueous urea (which
decomposes to ammonia when exposed to hot exhaust gas) be injected
into the exhaust stream, prior to entry into a catalytic reactor. In-line NOx
sensing is required to determine optimum instantaneous urea dose
quantities.
Chemical reactions are temperature sensitive in both cases.
This project involves the formulation of computer-based mathematical simulation
models of the fluid flow, heat transfer and chemical reaction effects involved in
combined NOx-PM after-treatment systems. Some experimental work may be
required for model verification. The ultimate objective is to achieve improved
effectiveness of complete after-treatment systems, through improved control.
Industry Link: Cummins Engines Inc., USA
Sponsorship under active negotiation with Cummins Engines Inc .
PhD Project to be jointly supervised by Dr. David Timoney (Mechanical
Engineering) and Dr. Dermot Malone (Department of Chemical Engineering)
Contact Details:
26th March 2004
Room 305, Engineering Building
Ph: ++353 1 716 1831
Email: [email protected]
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