Numerical simulations of high enthalpy flows around entry bodies

Abstract

Ablation flows around entry bodies are at highly nonequilibrium states. This paper presents comprehensive computational fluid dynamics simulations of such hypersonic flow examples. The computational scheme adopted in this study is based on the Navier-Stokes equations, and it is capable of simulating multiple-dimensional, non-equilibrium, chemically reacting gas flows with multiple species. Finite rate chemical reactions, multiple temperature relaxation processes, and ionizations phenomena with electrons are modeled. Simulation results of several hypersonic gas flows over axisymmetric bodies are presented and compared with results in the literature. It confirms that some past treatment of adopting less species for hypersonic flows is acceptable, and the differences from more species and more chemical reactions are not significant.

Study on the performance of spatial discretization schemes for hypersonic flow

“…Although many near space hypersonic vehicles, such as X-37 (Gülhan et al, 2014), X-51 (Schimisseur, 2015) and Falcon HTVs (Walker et al, 2008), have been succeeded in their missions, the exploration of aerothermodynamic problems is the principle obstacle because the velocities and altitudes at which these vehicles would operate are different, and sometimes more severe (Huang and Huang, 2015;Hu et al, 2016aHu et al, , 2016bLi et al, 2016), than those went through in the past. As future hypersonic vehicle quests to fly higher and faster, the environment surrounding the vehicle could be more dramatically changed (Hu et al, 2016a(Hu et al, , 2016bCai 2016;Yuan et al, 2017) and more difficult to simulate in ground-based test facilities (Doig et al, 2016), which makes the numerical simulations become increasingly important issues (Park et al, 2016;Boyd et al, 2010). Whether the existing numerical methods can apply to higher velocity is an urgent problem to be solved.…”