基于时间推进的涡扇发动机整机通流数值模拟

Numerical Investigation of Turbofan Engine Based onTime-Marching Throughflow Method

关键词:  航空发动机  整机模拟  时间推进  通流  叶片力

Key words:  Aero engine  Whole engine simulation  Time-marching  Throughflow  Blade force

摘要:

为实现航空发动机整机流场与性能快速分析，基于准三维控制方程模型，开发了整机通流数值模拟程序。程序基于计算流体力学理论，并考虑了引气、冷却和喷油等发动机中的物理现象。为模拟叶片对气流偏转作用，推导了一种鲁棒的无粘叶片力模型，同时采用粘性力模型模拟粘性损失效应。采用该程序对某型双轴分排涡扇发动机一个地面试车工况点进行了整机数值仿真，并与实验数据进行了对比验证。结果表明，所发展程序求解稳定，能够自动捕捉激波，并且可以快速获得完全收敛的航空发动机整机准三维流场，单工况点计算时长不大于30min。其中计算截面平均参数与实验测量偏差不大于8%，符合工程应用精度需求。

Abstract:

In order to achieve a fast simulation of flow filed and performance of a whole aero engine, a throughflow program is developed based on the quasi-three dimensional (Q3D) governing equations model. In this program, computational fluid dynamics (CFD) techniques are used to solve the governing equation, and many physical phenomena are modeled, including air bleeding, cooling and fuel injection etc. A robust inviscid blade force model is derived in order to obtain the flow deflection inside the blades, and a viscous force model is utilized to simulate the viscous loss effects. With this program, simulation for a dual-spool, separate exhaust turbo-fan engine at a ground test operation point is conducted, and computational results are compared with the experiment data. It is shown that the developed program is stable, capable of automatically capturing shock waves, and able to quickly obtain completely converged Q3D flow field of the whole aero engine, the calculation of which costs less than 30min on one operating point. The maximum error of area-averaged characteristic parameters is less than 8% compared to all test data, meeting the accuracy requirements of engineering applications.