时间：2019 年 2 月 21 日（周四）下午 15:00-16:30
地点：北京大学工学院力学楼 434 教室 

 

 

Abstract: 
Simulating two-phase flows in realistic industrial-complexity conditions remains an open problem. We present a phase-field method based on the Cahn-Hilliard equation that is able to simulate two-phase flow at high Reynolds number and at large density and viscosity ratios. We employ the entropy-viscosity method (EVM), applied both on the Navier-Stokes equations and phase-field equation, to stabilize the simulation in conjunction with an EVM-based artificial interface compression method (AICM) that maintains the sharpness of the interface. We implement this method based on a hybrid spectral-element/Fourier (SEF) discretization and demonstrate second-order accuracy in time and spectral convergence rate in space for smoothed fabricated solutions. We first test the accuracy and robustness of the stabilized SEF-EVM solver by solving the so-called three-dimensional LeVeque problem and compare against other available methods. Subsequently, we simulate a rising air bubble in a water container and find that the method is robust with respect to various parameters of the phase-field formulation. Lastly, we apply the method to simulate the onset and subsequent evolution of an air/oil slug in a long horizontal pipe using realistic parameters and incorporating gravity and surface tension effects. This is a particularly difficult flow to simulate with existing methods in realistic conditions and here we show that the new stabilized phase-field methods yields results in good agreement with the experimental data. 
Brief Biograph: 
王志成博士 2007 年获得北京交通大学热能与动力工程学士学位，2013 年在唐大伟研究员的指导下获得中国科学院工程热物理研究所博士学位并留所工作。2016 年至今在麻省理工学院从事博士后研究，与 G.E. Karniadakis 等教授合作，成果发表在 JFM, Computers & Fluids 等期刊。王博士的主要研究兴趣包括湍流模拟、两相流等。