Suspensions of particles in liquid are found throughout nature and industry, for instance chocolate, toothpaste, slurries and ceramics. Understanding their flow properties is crucial to describing the natural world and characterising engineering processes. We are just beginning to unravel the dramatic influence that particle-particle interactions have on their flow behaviour when the liquid is Newtonian and the particles are hard, repulsive and monosized (see Figure 1 and Ref [1]). In reality these conditions are rarely met: suspending liquids are often ‘viscoelastic’; particles are often soft or sticky and have large size distributions. How do the combined microphysics of these particle-level details control the resulting flow behaviour?

You will address this question using computational means, developing several key areas of expertise:

You will understand rheological characterisation of complex fluids;

Building upon codes developed in Edinburgh, you will implement particle-level force models to simulate bulk flow of suspensions.

You will develop post-processing techniques to generate viscosity and microstructural measurements;

Your work will improve our fundamental understanding and guide constitutive model development.

This computational project is supervised by Dr Chris Ness (School of Engineering, University of Edinburgh). It will involve regular interaction with experimentalists both locally and globally as well as exposure to real-world engineering of suspensions through our industrial colleagues. Interested candidates may contact the supervisor for further information (chris.ness@ed.ac.uk), and may wish to prepare a 1-page research proposal on a specific area relevant to this theme.

[1] Ness, Christopher, Ryohei Seto, and Romain Mari. "The physics of dense suspensions." arXiv preprint arXiv:2105.04162 (2021).