Numerical investigation of heat flux distribution in a deep gap based on chemical equilibrium

Abstract

Purpose The purpose of this paper is to perform the simulation to explore the gap flow field under a hypersonic air flow. Thermal protection systems of hypersonic vehicles generally consist of thermal insulation tiles, and gaps between these tiles probably cause a severe local aerodynamic thermal effect. Design/methodology/approach The discretizations of convection flux term and temporal term in the governing equation with chemical equilibrium, respectively, take AUSM+-up flux-vector splitting scheme and the implicit lower-upper symmetric Gauss–Seidel method. Based on these, the flow field in a deep gap is simulated by means of the computer codes that the authors have written. Findings The numerical results show that the heat flux distribution in a gap has a good agreement with experimental results. Importantly, the distribution of heat flux is “U” shaped and the maximum of the heat flux occurs at the windward corner of a gap. Originality/value To explore the gap flow field under a hypersonic air flow, which is a chemically reacting, all speed and viscous flow, a novel model with an equivalent ratio of specific heats is presented. The investigation in this paper has a guide for the design of the thermal protection system in hypersonic vehicles.

Flow and heat transfer analysis of laminar flow in hypersonic aircraft with variable specific heat capacity at small attack angles

“…Generally, for hypersonic flow problems, the analysis of the relevant physical parameters is mostly performed when the specific heat capacity is constant (Dong et al , 2006; Zhou et al , 2020; Giuseppe and Christian, 2022; Ding et al , 2023; Liu et al , 2023; Lee et al , 2023). However, in practice, the specific heat capacity is affected by many factors, so it is actually more suitable to be treated as a function of other variables (Anazadehsayed et al , 2017; Huang and Huang, 2017; Hu et al , 2017; Huang and Hu, 2018; Li et al , 2022; Yury et al , 2022; Yan and Zheng, 2023; Zhao et al , 2023). During flight, hypersonic aircraft will be subjected to severe aerodynamic heating, resulting in a dramatic increase in temperature, which changes the thermodynamic properties of the gas, and thus the thermal physical parameters of the air are no longer constant.…”

Numerical Prediction of Flow Field and Aerodynamic Heating in the Gap of Hypersonic Vehicle

“…Huang H analysed the influence of geometrical shape on the aerothermal environment. It was concluded that the number of vortices in the gap was mainly determined by the width-depth ratio when the inflow conditions were unchanged [14,15]. Leite established the model of flow field in the gap by numerical method, studied the influence of inflow parameters on the flow field [16].…”