论文部分内容阅读
低马赫数不可压流动中声速与流速大小差别巨大,采用基于可压缩流动控制方程的计算格式求解流场时,由于数值黏性的污染,解的精度低且收敛性差,通常可使用时间预处理技术来解决这一问题。在基于控制理论的优化方法中,共轭方程的Jacobian矩阵和流动方程的系数矩阵相似,因而在低流动马赫数下,求解共轭方程存在着与求解流动方程相同的数值污染和数值刚性问题。首先推导了带有预处理的Roe格式,然后发展了适合全速度流动的共轭方程求解方法,最后选取翼型和叶栅两个典型算例进行了验证。计算结果表明所发展的方法可很好地用于低马赫数时的气动反问题设计。
Low Mach number incompressible flow sound velocity and flow rate of the huge difference in size, the flow field calculated using compressible flow control equations based on the calculation of flow field, due to the numerical viscosity of the pollution, the solution of low accuracy and poor convergence, you can usually use the time pretreatment Technology to solve this problem. In the control theory-based optimization method, the Jacobian matrix of the conjugate equation is similar to the coefficient matrix of the flow equation. Therefore, under the low flow Mach number, there exists the same problem of numerical pollution and numerical rigidity as solving the flow equation. The Roe format with preconditioning is derived first, and then a conjugate equation solving method suitable for full velocity flow is developed. Finally, two typical examples of airfoil and cascade are selected for verification. The results show that the developed method can be applied to the design of aerodynamic inverse problem with low Mach number.