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Center for Nonlinear Studies |
Although ubiquitous in nature and in engineering applications, multiphase flows are notoriously difficult to predict. This is mainly due to two of their features: 1) Multiphase flows display discontinuous physical properties and moving interfaces/boundaries, rendering “traditional” numerical schemes--such as those used to simulate single-phase flows--inappropriate; 2) Multiphase flows are inherently multiscale, preventing the direct numerical simulation of most flows of practical interest, and requiring some degree of modeling to be introduced. The embodiment of these challenges is the example of an atomizing liquid spray, in which surface tension instabilities and the interactions with the surrounding turbulent environment drive interface breakup, and the formation of a dispersed phase consisting of very many small droplets.
In this talk, we will cover recent advances on the modeling of multiscale multiphase flows, starting with the numerical modeling of material interfaces and ending with the volume-filtered modeling of multiphase flows. We will discuss high-order extensions of current state-of-the-art moment-based approaches such as the volume-of-fluid or moment-of-fluid methods. We will then address the use of volume-filtered Euler-Lagrange methods for simulating large-scale suspensions of droplets or rigid particles, focusing on the closure problems arising from such formulations.
Bio: Fabien Evrard is an Assistant Professor of Aerospace Engineering at the University of Illinois Urbana-Champaign. He received his M.Sc. in Aerospace Engineering from the ISAE-SupAéro and his M.Res. in Applied Mathematics from the University of Toulouse, both in 2013. He then received his Ph.D. in Mechanical Engineering from Imperial College London in 2018, followed by post-doctoral positions at the University of Magdeburg and Cornell University. Fabien's research is on the modeling of strongly coupled multiphase flows by means of direct and large-eddy simulation, with the aim to advance fundamental understanding of these flows and guide engineering design. Recent research thrusts have focused on the modeling of surface tension driven multiscale interfacial flows, and on turbulent particle-laden flows such as the plume-surface interactions during powered spacecraft landing.
Host: Mikhail Jurievich Shashkov (XCP-4)