加权紧致非线性格式在热化学非平衡流数值模拟中的应用

Applications of high-order weighted compact nonlinear scheme for thermo-chemical nonequilibrium flow

高精度格式因其在较低的计算资源消耗下仍能保持足够的精度而在精细流动结构的模拟中具有独特优势。将显式5阶加权紧致非线性格式（WCNS-E-5)引人二维高温非平衡流计算，进行自由流速度5.0~5.7km/s的高焓风洞和高空条件下的圆柱非平衡流场数值模拟，得到正确的流场参数分布、壁面压力和壁面热流等结果与实验值吻合较好。计算结果表明,WCNS-E-5格式较2阶的MUSCL格式具有更好的热流网格收敛特性。分析并针对算例条件初步解决了高阶格式在刚性化学反应流模拟中的鲁棒性问题，为进一步采用高阶格式开展流场结构更加复杂的热化学非平衡流数值研究奠定了良好基础。

High-order scheme has advantages in the simulations of complex flow for its good behavior of preserving high spatial resolution with lower cost than the second order methods. WCNS-E-5 ( weighted compact nonlinear scheme) was applied in the simulations of thermo-chemical nonequilibrium flow around a cylinder with the freestream velocity from 5 km /s to 5. 7 km /s. The distribution of correct flow field parameter was acquired, the pressure and heat flux on the surface agreed well with the experimental data. WCNS-E - 5 also exhibited better performance on the grid convergence of heat flux than the second order MUSCL scheme. Results show that the present attempt to combine high order scheme with the calculations of stiff chemically reacting flow is basically successful, and it has established a good foundation for the further study.