报告题目：Multiscale Modeling and Computation of 3D Incompressible Turbulent Flows
报告人：胡新 加州理工学院
报告时间时间： 2012年5月11日(周五） 下午 3:00-4:30 
报告地点： 北京大学工学院力学楼434会议室 
主持人：唐少强教授

摘要：Developing an effective turbulence model is important not only for engineering applications but also for fundamental understanding of the flow physics. In this talk, we present a systematic way to derive the LES model based on multiscale analysis. The Smagorinsky model for homogeneous turbulence is recovered as an example to illustrate our mathematical derivation. Another example is turbulent channel flow, where we derive a simplified turbulence model based on the asymptotic flow structure near the wall. Additionally, we obtain a nonlinear model by using a second order approximation of the inverse flow map function.

In the second part, we treat turbulent flows as stochastic processes and a data-driven stochastic method is applied to compute the turbulent flows. Our preliminary results have shown that the data-driven stochastic method for fully developed turbulence offers decent approximations of statistical quantities with a coarse grid and a relatively small number of gPC base elements.

简介：胡新，分别于2004年和2007年在北京大学力学与工程科学系获得理学学士和理学硕士学位。2007年起，他在加州理工学院应用与计算数学系师从候一钊教授从事湍流多尺度分析和湍流模型的研究，并在数值随机偏微分方程方面也完成了一些有意义的工作，于2012年博士毕业。