PhD Opportunities in Granular Flow Characterisation – Linking Particles to Processes using Multiscale Modelling and Experiments

PhD Opportunities in Granular Flow Characterisation – Linking Particles to Processes
using Multiscale Modelling and Experimentation
 

Granular materials are ubiquitous in nature and extensively utilized in many processes in chemical/pharmaceutical,
civil, mechanical and mining industries. There is immense need to understand
how particle properties and interactions affect the bulk scale behaviour and
how process operations determine product characteristics. Ability to predict
such links is vital for migrating natural hazards and for optimising industrial
processes. Applicants are invited to pursue PhD in this exciting and important
field, working on one of the following research topics.

Research topics:

• Multiscale modelling of milling of semi-brittle materials

Milling is an important process to achieve desirable particle-size reduction in
pharmaceutical, chemical and mining industries. In order to control product
properties, maximise energy use and prolong device life, we propose to develop
a predictive toolbox for industrial milling process. We focus on coupling
fracturing at particle level with realistic particle dynamics in industrial
mills; and on upscaling from discrete to continuum behaviour. Development in
discrete element method will be calibrated against specially designed
experiments.

• Rheology of dense granular systems using an integrated multiscale approach

What do mayonnaise, shaving gel, toothpaste and sand pile have in common? They all can
sit still on a surface, but flow easily under applied forces. They have been
shown to behave similarly as dry granular media when they are dense enough and
close to jamming. In this research, we exploit the universality of these
different dense granular systems to characterise the rheological behaviour of generic
dense granular systems. We aim to establish a multiscale continuum theory with
greater predictive capability for a wide range of engineering applications. The
research will employ an approach integrating fundamental continuum theory,
novel experimentation using microscopy imaging and high-performance computing.

• Characterise and model of cohesive granular materials

Many granular materials, such as soils, snow and fine powders, are cohesive due to various
mechanisms. Behaviour of such materials is important in engineering for example
in stability of civil engineering structures, vehicle traction on snow and
handling of powders. Cohesion fundamentally changes the behaviour of granular
materials. Deeper scientific understanding of this behaviour is crucial for
improving engineering applications. We intend to further our understanding at
multiple scales and incorporate it into models accurately predicting bulk
behaviour of cohesive materials. We will characterise attractive forces at
particle scale using atomic force microscopy and measure cohesion using
microscale and element tests. Force models for discrete element method will be
developed and calibrated against such experiments. Such model will be used for
simulation of bulk flows.

• Mechanics of cell disruption in microalga processing

Microalgae can be used as a renewable source for biodiesel production. However, many technical challenges have
to be overcome to achieve an economically viable production. The oil extraction
from algal cells is one of the most challenging processes. Rapid and precise
cell disruption methods are called for to maximise the value of materials
obtained. In this research, we propose to combine experiments at cell level
with multiscale simulations. Measurement of cell mechanical properties will be
preformed using optical tweezers. The data will be used to calibrate force
models for algal cell disruption, which will in turn be employed for
large-scale simulation in order to design novel highly efficient processes for
oil extraction.

Eligibility and qualifications:

Applicants must be of outstanding academic merit and hold (or be expected to gain) either a
first class honours degree (or the international equivalent) or an MSc with
distinction (or the international equivalent). Enthusiastic and self-motivated
candidates are sought with a solid background in civil, mechanical, chemical
engineering, or in physics and mechanics. A good grasp of mechanics and
experience in programming and computational modelling would be
advantageous. 

Available scholarships:

Interested candidates are invited
to apply for competitive scholarships available in the School of Engineering
and in the University of Edinburgh. (This is a separate process from applying
to the above research projects.)

• PhD Studentships in Engineering
• Principal's Career Development PhD Scholarships
• Edinburgh Global Research Scholarship
• EPSRC Doctor Training Grant Studentships
• China Scholarships Council/University of Edinburgh Scholarships

Informal enquiries can be made to
Dr Jin Sun. (telephone: +44 0131 6519028, e‑mail: j.sun@ed.ac.uk).