风流知音(FLOWS:Physics & beyond)【WS-FTNCFD-2022|徐昆】高阶紧致气体动理学格式的最新进展 CFDST (2022年7月31日)1035
高阶紧致气体动理学格式的最新进展
专家简介:
报告摘要:
A general methodology for the development ofhigh-order compact scheme has been proposed recently. The ingredient of thescheme is composed of the following steps.
(1). Based on a generalized initial condition, beyondthe two constant states Riemann solver, construct a time accurate evolutionsolution at a cell interface; (2). Besides the WENO-type weighting functionsused in spatial data reconstruction, the nonlinear limiting procedure is alsointroduced in the temporal evolution in cope with the possible impingement of adiscontinuous wave passing through a cell interface within a time step; (3).Get time-accurate solutions of flow variables and corresponding fluxes at thecell interface and update the cell-averaged flow variables and their gradientsinside each control volume; (4). Based on the cell-averaged flow variables andgradients and the cells within the physical domain of dependence of thereconstruction cell, make compact initial data reconstruction at the beginningof next time step.
A compact gas-kinetic scheme (GKS) up to 8th-orderaccuracy in space and 4th-order in time has been constructed on 2D unstructuredmesh. Recently, a 4th-order compact GKS on 3D tetrahedral mesh has beendeveloped as well with the focus on the WENO-type initial data reconstruction.Nonlinear weights are designed to adaptively achieve high-order accuracy forthe smooth Navier-Stokes solution and super robustness for the strong shockdiscontinuity in 3D computation with tetrahedral mesh. At the same time, evenfor the 4th-order compact GKS, a large time step with CFL number 0.6 can besafely used in the simulation from the subsonic to the hypersonic flow. Thecompact reconstruction makes GKS be suitable for flow computation with complexgeometry.
A series of test cases in 3D will be used to validatethe scheme for compressible inviscid and viscous flow computations.