轴对称跨音速进气道外罩绕流的高效差分算法

 本文考虑轴对称跨音速进气道外流场的有限差分计算方法。采用守恒型位流方程、贴体坐标网格和精确边界条件,根据最佳收敛准则对轴对称情形设计出新的近似因式分解迭代格式,并将所设计的格式应用到计算皮托式进气口的轴对称跨音速流场。对几种典型进气口的计算表明,本文格式收敛快,计算结果与实验符合很好。

AN EFFICIENT FINITE-DIFFERENCE ALGORITHM FOR COMPUTING AXISYMMETRIC TRANSONIC NACELLE FLOW FIELDS

A finite difference method for computing the axisymme-tric, transonic flows over nacelle is presented in this paper. It is shown that the full-potential equation with conservation form for the axi-symmetric flows differs from the 2-D planar version only to the replacement of ρ by ρy, where P is the density, y the distance from the axis. When the extension from the planar to the axisymmetric case is made, however, the corresponding replacement used in the approximate-factorization iteration scheme for 2-D planar case does not lead to a convergence of the iteration. According to the optimum convergence criterion, a new AF scheme is constructed and then applied to solving the conservative full-potential equation for transonic nacelle flow, using body-fitted grid with exact boundary condition. Computation for several inlets shows the rapid convergence of this scheme and in an excellent agreement with the experiment results.