Variable high-order multiblock overlapping grid methods for mixed steady and unsteady multiscale viscous flows, part II: hypersonic nonequilibrium flows

The variable high-order multiblock overlapping (overset) grids method of Sjogreen & Yee (CiCP, Vol.5, 2008) 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 third-order 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 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

Variable high-order multiblock overlapping grid methods for mixed steady and unsteady multiscale viscous flows, part II: hypersonic nonequilibrium flows

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Numerical simulation of multi-component inductive plasma flows under chemical non-equilibrium

FLWINinfo:eu-repo/semantics/publishedHeat and mass transfer under plasma condition

Thermodynamic and Transport Properties for Inductive Plasma Modeling

A review is given of models for the thermodynamic and transport properties of inductive plasmas under conditions of local thermodyanimc equilibrium. The thermodynamic properties of individual species are computed using a statistical mechanics formulation based upon the rigid rotator and harmonic oscillator model. Complex cut-off criteria for the electronic levels and anharmonicity corrections are not needed for practical equilibrium calculations. An efficient iterative technique is proposed for the calculation of the equilibrium mixture thermodynamics properties. Through a Schur-complement approach the number of unknowns in the nonlinear system, which determines the equilibrium chemical composition, may be reduced to the number of basic elements. The method is demonstrated for equilibrium air computations. The plasma transport properties are computed with the method of Chapman and Enskog. Accurate formulas for the heavy particle and electron transport properties are discussed. Through a straightforward argument the result of Butler and Brokaw for the reactive thermal conductivity is shown to be valied for ionized equilibrium mixtures. Computed results for the thermodynamic and transport properties of air are compared with numerical and experimental results of other researcher