Professor Duncan Lockerby (Warwick University): Fluid dynamics simulation at the micro and nano scale
Fluid flows at the micro and nano-scale are characterised by non-equilibrium and non-continuum effects that place them beyond the modelling scope of conventional Computational Fluid Dynamics (CFD). Typically, a molecular or particle treatment of the liquid or gas, and any bounding solid surface, is required to accurately resolve such flows. However, the cost of these particle-based simulations is prohibitively costly for all but the simplest geometries. In this talk a number of approaches are introduced: the ‘hybrid’ approach, which combines the efficiency of CFD with the accuracy of particle simulation [1-3]; extended hydrodynamics, whereby continuum equations are solved that reach beyond the scale limitations of the Navier-Stokes model [4-5]; and fluctuating hydrodynamics, where thermal noise is incorporated into continuum models to capture important nanoscale interfacial phenomena [6]. The talk describes research funded in the UK by the EPSRC (EP/N016602/1; EP/K038664/1). For more information, visit: www.micronanoflows.ac.uk.
[1] A. Patronis and D.A. Lockerby, Multiscale simulation of non-isothermal microchannel gas flows. J. Comput. Phys, 270, pp 532- 543, 2014
[2] D.A. Lockerby, A. Patronis, M.K. Borg & J.M. Reese, Asynchronous Coupling of Hybrid Models for Efficient Simulation of Multiscale Systems. J. Comput. Phys, 284:261-272, 2015.
[3] M.K. Borg, D.A. Lockerby & J.M. Reese, A hybrid molecular-continuum method for unsteady compressible multiscale flows. J. Fluid Mech., 768: 388-414, 2015 [4] D.A. Lockerby & B. Collyer, Fundamental solutions to moment equations for the simulation of microscale gas flows. J. Fluid Mech., 806: 413-436, 2016 [5] R. Claydon, A. Shrestha, A.S. Rana, J.E. Sprittles & D.A. Lockerby, Fundamental solutions to the regularised 13-moment equations: Efficient computation of three-dimensional kinetic effects. J. Fluid Mech, 833, R4, 2017 [6]C. Zhao, J.E. Sprittles & D.A. Lockerby Revisiting the Rayleigh-Plateau instability for the nano scale. J. Fluid Mech, 861, R3, 2019