航空发动机整机空气系统流动与传热数值模拟

为了研究航空发动机整机空气系统内流动与传热特性,本文以涡扇发动机整机空气系统为对象,主要包括压气机盘腔、涡轮盘腔、低压轴前后腔、前后轴承腔等旋转盘腔和大量的流阻换热单元以及相邻的结构部件。所研究的是一个多腔相连,多进口,多出口,流固耦合传热的复杂问题,分析了发动机真实状况下空气系统内的流动与传热特性。采用Mixture多相流模型进行数值计算得到了该系统的速度场、压力场和温度场。结果表明：该系统内的流场是复杂的多涡流场,多个出口出现燃气倒灌；整个系统的腔压大致从前到后逐渐升高；由于主流通道燃气的入侵,导致高、低压涡轮盘的温度较高,后轴承腔内滑油的冷却作用较为明显。本文的工作使得对发动机整机空气系统的研究不再局限于一维计算,为空气系统的设计提供了理论依据。

Numerical Simulation of Flow and Heat Transfer in Air System of an Aero-Engine

In order to study the flow and heat transfer in the aero-engine air system, the air system of a turbofan engine was analyzed. The air system includes compressor cavities, turbine cavities, front and back cavities of low pressure shaft, front and back bearing cavities and a large number of flow resistance heat transfer units and adjacent structural components. The research was a multi-cavity, multi-inlet, multi-outlet, fluid-solid phase coupling heat transfer problem, and analyzed the flow and heat transfer in the aero-engine air system under real working conditions. Mixture multiphase model was used to simulate the velocity, pressure, and temperature. Results show that the flow field is a complex multi-vortex flow filed, and multiple outlets have gas backflow; the pressure increases gradually from front to back; due to the invasion of the outer duct gas, the temperature is high of the high and low pressure turbine disk, the cooling effect of the lubricating oil in the back bearing cavity is obvious. The work of this paper makes the research on aero-engine air system no longer limited to one-dimensional calculation, which provides a theoretical basis for the design of the air system.