Abstract: Aerodynamic heating process and thermal stress of ZrB2-SiC leading edge as the component of scramjet engines were numerically investigated by finite-difference and finite-element methods, and the simulation results were verified through thermal structure tests with arc-heated wind tunnels. Simulation results showed that the temperature at stagnation point reached 1870 K in 5 s, and thermal stress of structure was up to 1240 MPa which was beyond the fracture strength of ZrB2-SiC material, when the inflow Mach number was 6, total pressure 4.41 MPa, total temperature 2375 K, with the radius of leading edge at 0.125 mm. The experimental results show that the temperature at stagnation point reached 2175 K in 5 s, and the leading edge cracked in thermal structure tests. Simulation results were in reasonable agreement with the experimental results.

Key words: ZrB2-SiC, numerical simulation, leading edge, aerodynamic heating, thermal stress

摘要： 分别采用有限差分法和有限单元法对ZrB2-SiC前缘构件高超声速气动加热过程及其内部热应力进行了数值模拟，并以电弧风洞地面模拟实验对计算结果进行了验证. 计算结果表明，飞行马赫数为6、总温2375 K、总压4.41 MPa、结构前缘半径为0.125 mm时，5 s时驻点温度达1870 K，内部最大热应力达1240 MPa，这将导致服役过程中材料失效. 电弧风洞实验结果表明，5 s时驻点温度达2175 K，材料前缘因承受的应力超过其弯曲强度而断裂.计算结果与风洞实验结果吻合较好.

关键词: ZrB2-SiC, 数值模拟, 前缘, 气动加热, 热应力