改善航空发动机特性计算收敛性的方法

Research on the method to solve convergence problem in aero turbo-engine performance computation

详细分析了航空涡轮发动机部件共同工作的非线性方程组的求解收敛性问题,统计出不收敛的类型并分析了不收敛的机理.针对常见的不收敛问题,以牛顿迭代法为基础,分别提出了以发动机部件特性图为基础的独立变量值限制法、独立变量初值拟合法、变步长牛顿法以及部件特性扩展法等解决措施.特性计算程序中采取这些改进的方法后,对某型定几何单轴涡喷发动机和某型尾喷管喉部面积可调的变几何双轴涡扇发动机特性计算结果表明,发动机特性计算的收敛性和收敛速度得到大幅度提高.

The convergence problems of solving the nonlinear equations of aero turboengines were studied in detail, while the non-convergence cases were counted and the mechanism was analyzed. For solving the common non-convergence problems, some improved methods based on Newton method were presented, such as： limitation of initial variables of the nonlinear equations based on components maps, polynomial fit of initial values of variables of the nonlinear equations, variable step Newton method and expansion of components＇ maps. These improved methods were employed in performance computing program. The performance calculation results of some fix geometry turbojet and variable geometry turbofan show that the convergence and convergence rate have been improved greatly.