报告题目：

A new discrete velocity method or a lattice Boltzmann method

演讲人：

Prof. Yonghao Zhang

 

（Department of Mechanical & Aerospace Engineering,

University of Strathclyde, Glasgow, UK）

 

时间：2014年7月25日（周五）上午10:00

地点：力学所主楼312会议室

 

报告摘要：

Our recent development of lattice Boltzmann (LB) method for modelling gas flows beyond the Navier-Stokes hydrodynamics will be discussed. Theoretical analyse on the accuracy of high-order LB models for rarefied gas flows shows that the LB model can reduce to the linearised Bhatnagar-Gross-Krook (BGK) model in the incompressible limit. Numerical analysis shows that the order of Gauss-Hermite quadrature rather than the order of the Hermite expansion in the LB equilibrium distribution is the key to modelling accuracy. We will discuss the unique features of high-order LB method in comparison with discrete velocity method.

We will then present our numerical simulation results and discuss the modelling accuracy. With a moderate discrete velocity set, this new discrete velocity model can accurately recover steady and transient solutions of the kinetic equation in the slip-flow and early transition regimes. For highly non-equilibrium phenomena characterised by high Mach numbers, such as viscous heating and force-driven Poiseuille flow for large values of the driving force, are more difficult to capture quantitatively in the transition regime using modest discrete velocity set with computational efficiency in mind, although improved accuracy is observed as the number of discrete velocities is increased.

 

报告人简介：

Yonghao Zhang (YHZ) is Professor of Fluid Mechanics at Strathclyde University UK and Director of the James Weir Fluids Laboratory (www.strath.ac.uk/jwfl/). After completion of his PhD study in Mechanical Engineering at the University of Aberdeen, UK in 2001, he worked as a Computational Scientist, then Senior Scientist at Daresbury Laboratory, UK. In 2007, he joined the Department of Mechanical & Aerospace Engineering at the University of Strathclyde as John Anderson Research Lecturer.

YHZ’s expertise is in the fluid dynamics at micro/nano-scales, which presents an important technological challenge, with long-term research and industrial implications. His group is the first to combine the unique features of lattice Boltzmann and discrete velocity methods for simulating rarefied flows. Recently, a fast spectral method for solving the Boltzmann equation, considering different molecular potential models has been developed in his group. YHZ’s other research activities centre on complex flow physics, including multiphase flows, droplet technologies and granular flows. In the last 5 years, his research has been funded by UK Research Councils, European Commission, Royal Academy of Engineering, Royal Society of Edinburgh, and the Leverhulme Trust to over £2M. He is currently Royal Academy of Engineering/Leverhulme Trust Senior Research Fellow, and a Fellow of Institute of Mechanical Engineers.