Abstract:

The interaction between high-enthalpy/chemical-nonequilibrium flow and surface materials brings complex coupling convective heat transfer characteristics, leading to weak applicability of hot-wall correction method (HWC) for rapid evaluation of aerodynamic thermal environment. In view of the above problems, this paper deals with HWC improvement via coupling numerical simulation of catalytic heating on carbon-based materials in carbon-oxygen dissociation environment. On the basis of the numerical simulation of hypersonic aerodynamic heating/structural heat transfer interaction, the chemical non-equilibrium effect and the interface high-temperature chemical effect were deeply analyzed. The coupling results show that the linearity of wall chemical heatflux and temperature is weakened due to interface thermochemistry, while the temperature-gradient part maintains high linearity. Accordingly, a new idea to improve HWC was proposed by decomposing the contribution of heatflux into two physical processes: one obeying the conventional HWC, and the other independent of boundary layer profiles. In-depth analysis shows that the latter can be simply dealt with by computing reaction rates from chemistry mechanism, eliminating the need for full CFD/CHT coupling computation.

Key words: chemical reaction, computational fluid dynamics, convection, hot-wall correction, interface physics, non-equilibrium effects, hypersonic

摘要：

高超声速飞行产生的化学非平衡效应及其与表面结构/材料传热的相互作用，带来更为复杂的耦合对流换热特性，并造成用于气动热环境快速预测与评估的热壁修正方法适用性变差。针对上述问题，以碳氧离解环境碳基材料耦合催化加热为研究对象，在高超声速气动热与结构传热耦合数值模拟的研究基础上，进一步考虑化学非平衡效应和气固界面高温化学效应，分析耦合条件下飞行器对流换热特性，并根据耦合模拟结果提出了通过对气动加热按物理过程的贡献进行分解来改进热壁修正方法的新思路。

关键词: 化学反应, 计算流体力学, 对流, 热壁修正, 界面物理, 非平衡效应, 高超声速