流体网络节点残量修正算法的改进

为了提高流体网络求解的收敛性与稳定性,对网络节点残量修正算法进行改进。基于理论分析,提出使残量修正算法大范围收敛的初值赋值规律,并通过简单模型的数值分析加以验证;在节点残量修正显式迭代的基础上,提出隐式梯形迭代格式,扩大最大迭代步长。基于改进方法,以某典型航空发动机空气系统为例进行计算,获得空气系统各节点的压力、温度以及各支路的质量流量。该计算过程显示,相对于残量修正显式迭代,改进计算振荡大幅度减弱,收敛速度提高了80%以上。结果表明:改进算法有效地提高了流体网络求解的稳定性和收敛性。

Improvement of Fluid Network Node Residue Correction Algorithm

In order to enhance stability and convergence of solving fluid network, the network node residue correction algorithm is investigated. Based on theory analysis, a principle of setting initial values for network is put forward which enables the algorithm to converge in large scale. Implicit trapezoid iteration formula is advanced on the foundation of node residue correction explicit expression, making maximum iterative step expand a lot. One certain aero engine secondary air system is computed with the improved algorithm above as an example, whose pressure distribution, temperature distribution and mass flow distribution are obtained. The computation process shows that calculation oscillation is greatly reduced and convergence speed is improved by more than 80% compared with the explicit iteration. It indicates that the improved algorithm ameliorates stability and convergence of solving fluid networks effectively.