Duncan Lockerby (Warwick University, UK)

Duncan Lockerby is Professor in the Fluid Dynamics Research Centre at the University of Warwick, where he has been since 2006. His current research interests lie in: nanoscale fluid mechanics; multiscale modelling; fluctuating hydrodynamics, microscale (rarefied) gas dynamics; particle suspensions, and aerosol dynamics. He has worked in partnership with a number of institutions and companies, over a number of years, on the multiscale modelling of micro and nanoflows. Before this, he worked on a variety of topics in fluid mechanics, including biomechanical flows and turbulence control. He was awarded the Programme Grants twice, the flagship grants of the UK Research Councils. More details can be found at https://warwick.ac.uk/fac/sci/eng/staff/dal/.

Title: Modelling the dynamics of airborne particles at the microscale
Abstract: Low-speed gas flow around microscale particles (e.g. soot and other pollutants), and through suspensions of particles, are surprisingly rich in physics and challenging to simulate. On top of the usual challenge of simulating low-Reynolds number flow around particles, their scale renders the conventional Stokes equations, and associated boundary conditions, inaccurate, and unable to capture rarefied effects such as thermophoresis and velocity slip. The problems are especially challenging for non-canonical geometries in the `transition’ regime in Knudsen number (Kn) – defined as the ratio of the molecular mean-free-path to the characteristic scale of the particle. On top of this, there are the effects of Brownian motion (in translation and rotation). In this talk we discuss various computational approaches to tackle these challenges, and apply these to some multi-physics applications, including suspensions of many interacting particles and thermophoretic flow around soot.