基于高精度算法的结冰翼型分离流动数值模拟

Numerical simulation of separated flow around iced airfoil based on high-order schemes

CFD在航空航天领域应用广泛,在飞机结冰研究方面也成效斐然。但对于结冰后流场结构分辨、关键气动特性预测等一系列问题,当前主流的模拟方法仍存在数值格式精度低、流场细节捕捉不足的缺陷。针对此问题,提出将高精度格式和雷诺应力模型结合,应用于结冰翼型分离流动模拟研究,并与低阶精度格式、不同湍流模型进行对比。计算结果表明,使用相同湍流模型,高阶格式比低阶格式所预测的气动特性曲线与实验值更吻合,最大升力系数的相对误差更低;使用相同精度格式离散,雷诺应力模型对流场结构,特别是精细结构的分辨率明显优于SA模型和k-ε模型,翼型表面压力分布和分离泡再附点均与实验值吻合良好。对结冰翼型的复杂流场精细模拟,高精度格式结合雷诺应力模型的算法,具有重要的科学研究价值及应用前景。

Computational Fluid Dynamics(CFD)is now widely used in aeronautics and astronautics as a crucial method of aircraft icing research.There exists deficiency in simulation accuracy and details capturing in the field of flow field structure or flow mechanism after icing and the change of aerodynamic characteristics.In this paper,numerical simulations of separated flow around three iced airfoils are conducted by using the SSG/LRR-g turbulence model equipped with the high-order discretization method WCNS,and compare with lower order accuracy schemes and different turbulence models.It is found that using the same turbulence model,the drag and pitching moment coefficient predicted by the WCNS are in better agreement with the experimental data than those predicted by the lower order scheme,and the error of the maximum lift coefficient predicted reduced.In addition,using the same accuracy scheme,pressure coefficient distribution at the surface,and the re-attached point of the separation bubble obtained by the current work are comparable to those of the experiment.