时间：2019年8月23日9:00-12:00

　　地点：知新楼B座924报告厅

　　报告人：

　　1. Jilu Wang, 北京计算科学中心

　　Title: A linearized finite element method for MHD equations in nonconvex domains

　　Abstract: In this work, we proposed a new fully discrete linearized $H^1$-conforming Lagrange FEM for the two-dimensional megneto-hydrodynamics equations based on a magnetic potential formulation such that the numerical solutions would converge not only in convex and smooth domains but also in nonconvex and nonsmooth domains. The convergence of subsequences of the numerical solutions is proved only based on the regularity of the initial conditions and source terms, without extra assumptions on the regularity of the solution. Numerical examples are given to support the theoretical analysis.

　　2. Huangxin Chen, 厦门大学

　　Title: Threshold dynamics method for topology optimization for fluids

　　Abstract: In this talk we will introduce an efficient threshold dynamics method for topology optimization for fluids modeled with the Stokes equation. We aim to minimize an objective energy function that consists of the dissipation power in the fluid and the perimeter approximated by nonlocal energy subject to a fluid volume constraint and an incompressibility condition. In order to solve the problem in the whole domain, a one-domain approach for fluids over porous media will be introduced. Then we show that the minimization problem can be solved with an iterative scheme in which the Stokes problem is approached with a Brinkman problem. The indicator functions of the fluid-solid regions are then updated according to simple convolutions followed by a thresholding step. The total energy decaying property of the iterative algorithm can be obtained. Some numerical results will be shown to verify the efficiency of the proposed algorithm.

　　3. TBA

　　邀请人：芮洪兴