Hypersonic Low-Density Aerothermodynamics of Orion-Like Exploration Vehicle

IXV post-flight reconstruction and analysis of the aerothermodynamic measurements along the rarefied portion of the reentry trajectory

“…Finally, in [48], Votta employed Yun and Mason collision integrals for the computation of the species viscosity, Eucken's formula for the species conductivity and the mixture quantities were computed with Wilke's formula. For their computations at 85 km, their CFD solver gave a wall heat flux distribution around 60% smaller than the DSMC solution for the non-catalytic case.…”

“…In the same way but for a greater Knudsen number, Casseau's work [42] shows that for a simple reacting flow around a 2D cylinder, both solutions can reach a satisfactory agreement. However, the consideration of a reacting 5 species air flow around a more complex geometry (axisymmetric probe) [48] led to more significant discrepancies between the computed flowfield solutions (difference in the shock thickness) except in the near-wall region. In summary, these studies show that both methods can be brought in good agreement if the Knudsen number is sufficiently small and if the flow as well as the geometry are sufficiently simple.…”

Numerical simulation of hypersonic flow with non-equilibrium chemical reactions around sphere

“…Navier-Stokes equations are also applied in the transient mode, which is realized in the range of variation of the Knudsen criterion 0.01 < Kn < 0.1. The slip condition is used for the tangential velocity on the wall [35]. For Knudsen numbers exceeding 0.1, the flow is free molecular and is not described by the Navier-Stokes equations.…”

Influence of chemical models on heat flux for EXPERT and Orion capsules

“…According to the test matrices, the wall temperature of EXPERT is 300 K in the whole altitude interval 65-105 km 1 and the wall temperature of Orion ranges from 1464 to 494 K in the altitude interval 75-125 km. 5 The surface recombination reactions, implemented in both codes…”

“…A number of articles have been already written about aero-thermo-dynamic behavior both of EXPERT [1][2][3] and of Orion. 4,5 The aim of the present article is to provide a further contribution to the evaluation of the heat flux to the capsules. More specifically the topics of this article are as listed below.…”