低Mach数翼型绕流数值模拟的低耗散预处理格式

Low-Diffusion Preconditioning Scheme for Numerical Simulation of Low-Speed Flows Past Airfoil

低Mach数流动中,基于可压缩流动的数值模拟算法存在严重的刚性问题,预处理方法可以有效地解决这一问题,但其计算结果不稳定.基于原有的预处理Roe格式,引入可调节参数,得到一种新的低耗散格式.该格式可以减弱边界层以及极低速区域的过度耗散,使得整个流场计算稳定.低Mach数、低Reynolds数定常圆柱绕流和低Mach数、高Reynolds数翼型(NACA0012和S809)绕流3个验证算例表明,带可调节参数的低耗散预处理方法正确可靠,是低速流动数值模拟的有效方法.

The reconditioning technique addresses the stiffness of low Mach number flow,while the stability was poor.Based on the conventional preconditioning method of Roe＇s scheme,a new low-diffusion scheme was proposed.An adjustable parameter was introduced to control the numerical dissipation in the new scheme,especially the over dissipation in the boundary layer and extremely low speed region.Numerical simulations of low Mach and low Reynolds number flows over a cylinder,low Mach and high Reynolds number flows over NACA0012 and NH02-18 airfoils were performed to validate the new scheme.All results of the three test cases are found to agree well with experiment data,demonstrating the applicability of the suggested scheme to low Mach number flow simulations.