Variable High-Order Multiblock Overlapping Grid Methods for Mixed Steady and Unsteady Multiscale Viscous Flows,Part II:Hypersonic Nonequilibrium Flows  

作　　者：Andrea Lani Björn Sjögreen H.C.Yee William D.Henshaw 

机构地区：[1]NASA Ames/Stanford Centre for Turbulence Research,Palo Alto,CA,USA [2]Lawrence Livermore National Laboratory,Livermore,CA,USA [3]MS 258-5,NASA Ames Research Center,Moffett Field,CA,USA

出　　处：《Communications in Computational Physics》2013年第2期583-602,共20页计算物理通讯（英文）

摘　　要：The variable high-order multiblock overlapping(overset)grids method of Sj¨ogreen&Yee[CiCP,Vol.5,2009]for a perfect gas has been extended to nonequilibrium flows.This work makes use of the recently developed high-order well-balanced shock-capturing schemes and their filter counterparts[Wang et al.,J.Comput.Phys.,2009,2010]that exactly preserve certain non-trivial steady state solutions of the chemical nonequilibrium governing equations.Multiscale turbulence with strong shocks and flows containing both steady and unsteady components is best treated by mixing of numerical methods and switching on the appropriate scheme in the appropriate subdomains of the flow fields,even under the multiblock grid or adaptive grid refinement framework.While low dissipative sixth-or higher-order shock-capturing filter methods are appropriate for unsteady turbulence with shocklets,second-and thirdorder shock-capturing methods are more effective for strong steady or nearly steady shocks in terms of convergence.It is anticipated that our variable high-order overset grid framework capability with its highly modular design will allow for an optimum synthesis of these new algorithms in such a way that the most appropriate spatial discretizations can be tailored for each particular region of the flow.In this paper some of the latest developments in single block high-order filter schemes for chemical nonequilibrium flows are applied to overset grid geometries.The numerical approach is validated on a number of test cases characterized by hypersonic conditions with strong shocks,including the reentry flow surrounding a 3D Apollo-like NASA Crew Exploration Vehicle that might contain mixed steady and unsteady components,depending on the flow conditions.

关 键 词：Unstructured mesh hypersonic flows thermo-chemical nonequilibrium residual distribution schemes double cone 

分 类 号：O35[理学—流体力学]