Asymptotic preserving schemes for radiative transfer systems

报告人: 江松 院士（北京应用物理与计算数学研究所）

题目：Asymptotic preserving schemes for radiative transfer systems

时间: 4月23日上午09:00开始

地点: 浙江大学玉泉校区工商楼200-9

摘要： Radiative transfer systems find a wide range of applications, for example, in the inertial constrained fusion research and in astrophysics. The solution of a radiative transport system can cover both optical thin and optical thick regimes due to the large variation of photon's mean-free path and its interaction with the material. In the small mean free path limit, a nonlinear time-dependent radiative transfer system can converge to an equilibrium diffusion equation due to the intensive interaction among radiation and material. In the optical thin limit, the photon free transport mechanism will emerge. In this talk, we are going to develop an asymptotic preserving unified gas kinetic scheme (AP-UGKS)  for both grey and frequency-dependent radiative transfer systems, where the radiation transport equation is coupled with the material thermal energy equation. The newly developed scheme has the asymptotic preserving property in the optically thick regime to capture the diffusive solution without using a cell size being smaller than the photon's mean free path and time step being less than the photon collision time. Besides the diffusion limit, the scheme can capture the exact solution in the optical thin regime as well. Due to the direct modeling for the time evolution of the interface radiative intensity, a smooth transition of the transport physics from optical thin to optical thick can be accurately recovered. Many numerical examples are included to validate the current approach. Extensions to more complex systems will be presented.

江松院士介绍

1982年四川大学数学系本科毕业，1984年获西安交通大学计算数学硕士学位，1988年获德国波恩大学应用数学博士学位。1988年至1990年间在德国波恩大学做博士后，1996年底获得德国教授（授课）资格(Habilitation)。北京应用物理与计算数学研究所历任研究室主任、科技委主任、副所长、党委书记。研究领域主要为流体力学的数学理论与数值方法，重点为可压缩Navier-Stokes(NS)方程和Euler方程的适定性理论与数值模拟方法研究。现任美国、德国、英国、香港和中国大陆六种SCI杂志的编委。他在可压缩NS方法与磁流体力学方程的数学理论、武器物理计算方法和重大武器型号软件平台研制等方面取得了突出成绩。曾获国家自然科学二等奖、军队科技进步一等奖，入选国家“百千万人才工程”。并于1998年获第六届中国青年科技奖，2002年获得国家基金委“杰出青年基金”资助，2003年获中国科协“求是杰出青年奖”，2003年认定为“四川省学术和技术带头人”，2014年评选为中国工程物理研究院杰出专家。2015年当选中国科学院院士。

联系人：张挺老师（zhangting79@zju.edu.cn）

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