Numerical Simulation of Weakly Ionized Hypersonic Flow for Reentry Configurations

Abstract

Numerical simulations of axisymmetric flows over reentry configurations at hypersonic conditions using a Navier-Stokes solver are presented. The Navier-Stokes equations are modified using Park's two-temperature model to account for thermochemical nonequilibrium and weak ionization effects. The finite-volume method is used to solve the set of differential equations. The code has the capability to handle any mixture of hexahedra, tetrahedra, prisms and pyramids in 3D or triangles and quadrilaterals in 2D. The results in this paper only use quadrilaterals. Numerical fluxes between the cells are discretized using a modified Steger-Warming Flux Vector Splitting approach which has low dissipation and is appropriate to calculate boundary layers. A point or line implicit method is used to perform the time integration. Pressure, heat transfer rates and electron number density profiles are compared to available experimental and flight measurements.

A Two-Temperature Open-Source CFD Model for Hypersonic Reacting Flows, Part One: Zero-Dimensional Analysis

“…Throughout this paper chemical reactions are considered to be irreversible to be in line with the dsmcFoam study. The relation giving the backward rate constant, k b , is thus omitted here but one could refer to [30] to compute its value.…”

“…Translational-vibrational and vibrational-vibrational energy exchanges are then determined and coupled with an appropriate chemistry module. Among such CFD codes dedicated to the hypersonic regime are NASA's DPLR (Data-Parallel Line Relaxation from the National Aeronautics and Space Administration) [10], LAURA (Langley Aerothermodynamic Upwind Relaxation Algorithm) [11], VULCAN (Viscous Upwind aLgorithm for Complex flow ANalysis) [12], LeMANS (The Michigan Aerothermodynamic Navier-Stokes solver) [13,14], and US3D (UnStructured 3D) [15,16] from the University of Minnesota. For rarefied flow conditions, a DSMC solver called dsmcFoam has been developed and validated within the framework of the open-source CFD platform OpenFOAM [17] at the University of Strathclyde [18,19].…”

Study of Conservation on Implicit Techniques for Unstructured Finite Volume Navier-Stokes Solvers

“…Equation (27) applies the term to decrease the value at the faces parallel to the wall inside the boundary layer (Scalabrin, 2007). This artificial dissipation model has shown an important role in the prediction of boundary layer profiles (Junqueira-Junior, 2012;Junqueira-Junior et al, 2013).…”

“…For Eq. (26) one suggests α = 6, but some problems may require larger values (Scalabrin, 2007). Th e applied formulation was originally created with interest on studying fl ows over reentry capsules.…”

“…The solver used in the present work is Le Michigan Aerothermodynamics Navier-Stokes Solver (LeMANS). Th e original framework was developed by Scalabrin (2007) at the University of Michigan to simulate hypersonic fl ows over reentry capsules. It is a three dimensional (3-D) numerical solver that uses the fi nite volume formulation for unstructured meshes to solve the RANS equations coupled with non-equilibrium chemical reaction equations and the Spalart-Allmaras (SA) turbulence model (Spalart and Allmaras, 1992;1994).…”