高超声速尖双锥流动高精度数值模拟

摘要

以25°／55°尖双锥外形的高超声速低焓层流流动模拟为例，对高阶加权紧致非线性格式模拟激波／边界层干扰流动的能力进行验证和确认。空间离散采用二阶 MUSCL 和三阶、五阶加权紧致非线性格式，时间离散采用二阶精度双时间步方法，通量函数采用混合 Roe-Rusanov，AUSMPW ＋，Van Leer 等，对比了不同精度空间离散格式对时间、网格收敛特性和通量函数耗散特性的影响。数值模拟结果表明采用高精度空间离散格式能在较疏的网格上获得收敛解，并能消除结果对通量函数的敏感性，但收敛需要推进更久的计算时间。数值模拟结果与实验测量结果吻合良好，满足工程精度要求。%Hypersonic low enthalpy laminar flows of double cone with 25°/55°geometry were simulated by using high-order WCNS (weighted compact nonlinear schemes),and their capabilities to accurately predict laminar shock wave /boundary layer interaction were examined.The simulations were performed through adopting the second order MUSCL,the third-order and the fifth-order WCNS as spatial discretization schemes, employing the second-order dual time-stepping approach for time integration and using different flux functions,such as hybrid Roe-Rusnov, AUSMPW + and Van Leer,for comparison.The effects of high-order methods on time and grid convergence,as well as the dissipation characteristics of flux functions,were analyzed.The numerical simulation results indicate that the high-order methods can obtain well-resolved results on coarse grid and eliminate the sensitivity of flux functions.However,the high-order methods need longer computational time to reach convergence.The computed results show good agreement with the experimental data,and the computational accuracy may be characterized as reasonable for most engineering purposes.