轴对称进气道外罩跨音速非守恒型全位势流AF3算法

本文针对轴对称进气道外罩跨音速绕流问题的特点,采用了贴体坐标网格;并对这类网格拓扑构造了三种Baker的隐式近似因式分解AF3有限差分迭代算法。通过理论分析与数值实验,找到了既能计算亚临界情形,又能计算超临界情形的AF3格式;并就此格式讨论了适合于进气道绕流特性的AF3迭代格式中间变量的提法,具体提出了格式实施的相应方法,研制了可供分析任意轴对称进气道外罩跨音速特性的计算程序。由于采用了任意曲线坐标系上的轴对称非守恒型全位势方程适合于用不同方法生成的计算网格,因此,本文的工作还有可能进一步推广到计算更复杂的轴对称进气道跨音速绕流问题。计算表明,本方法收敛快,结果好。

An AF3 Algorithm for the Calculation of Transonic Nonconservative Full Potential Flow around Axisymmetric Inlet Cowls

Three types of fully implicit Baker's AF3 schemes, approximate factorization (AF) iteration algorithms, have been constructed for the transonic flow around axisymmetric inlet cowls in body-fitted coordinate mesh.A suitable AF3 scheme has been found for the calculation of both subcritical and supercritical flow fields about axisymmetric inlets by numerical experiments and analysis comparisons. With this AF3 scheme, a computer program has been developed for analyzing the transonic flow over arbitrary axisymmetric inlet cowls. An axisymmetric nonconservative full potential equation in arbitrary curved coordinate system, which is suitable for different grid topologies has been used in the present work, so it is quite possible for us to make a further extension for the solution of more complicated flow fields about transonic axisymmetric inlets. The numerical calculations show that the method presented converges rapidly to give good agreements with experimental or existing results.