高超声速飞行器热环境与结构传热的多场耦合数值研究

Multi-field coupling numerical analysis of aerothermal environment and structural heat transfer of hypersonic vehicles

为了准确预测高超声速飞行器面临的严峻气动热/力环境以及结构的热力响应,发展了高超声速流动与结构传热耦合框架。采用分区求解方法,通过耦合界面的实时数据传递,实现了基于Navier-Stokes方程的高超声速化学非平衡计算流体力学(CFD)求解器与结构的热力全耦合有限元法(FEM)求解器的多场耦合计算,建立了高超声速飞行器的多场耦合数值分析方法。首先对经典高超声速圆柱绕流实验进行了耦合计算,结果与实验值吻合良好。然后针对典型的超高温陶瓷(UHTC)材料的耦合传热问题进行了数值研究,考虑热传导效应对气动热环境和结构热响应预测的影响,结果表明对于复杂外形且热导率相对较高的UHTC材料,结构内部热传导对热环境和表面温度分布的影响不可忽略。最后针对UHTC材料热物性(比热和热导率)非线性对高超声速流动传热过程的影响进行了研究,结果表明当比热和热导率处于合理的误差范围内时,材料表面温度响应对其变化并不敏感。

A coupling framework of hypersonic flow,heat transfer and structural response is presented in this paper in order to accurately predict aerodynamic environment,extreme aerothermal environment,as well as thermal and structural response for hypersonic flight.Multi-field coupling analysis is implemented in conjunction with the hypersonic chemical non-equilibrium computational fluid dynamics（CFD）solver and the fully coupled thermo-structural finite element method（FEM）solver by using partition algorithm,with a real time data exchange between non-matched meshes.This coupling method is validated by comparison with the experiment of a turbulent flow over a circular cylinder and good agreements with experiment are achieved.Coupling analysis of ultra high temperature ceramics（UHTC）is also conducted,and the effects of thermal conductivity on the prediction of aerothermal environment and structural thermal response have been considered.The results show that the effects of structural internal heat conduction on aerothermal environment and surface temperature distribution cannot be neglected for a structure with high thermal conductivity and complex geometry.At last,the effects of non-linear thermophysical properties（specific heat and thermal conductivity）of UHTC on hypersonic flow and heat transfer process have been studied.The results show that the surface temperature of structure is not sensitive to thermal conductivity and specific heat when thermal conductivity and specific heat are in a limit of allowable error.