旋转反压与离心式压气机叶片相互作用数值模拟研究

Numerical Simulation of Interaction Between Rotating Backpressure and Centrifugal Compressor Blades

关键词:  旋转爆轰燃烧室  离心式压气机  旋转反压  压气机流场  复杂波系

Key words:  Rotating detonation combustor  Centrifugal compressor  Rotating back pressure  Compressor flow field  Complex wave system

摘要:

由于旋转爆轰燃烧室具有自增压、热效率高的特点，将航空涡轮发动机的燃烧室替换为旋转爆轰燃烧室可进一步提高发动机性能。本文基于非稳态雷诺时均Navier-Stokes方法，采用k-ε湍流模型，针对旋转反压与离心式压气机叶片的相互作用开展三维数值模拟，研究旋转反压形成的前传压力波与扩压器及叶轮叶片的相互作用，分析旋转反压传播方向对前传压力波运动过程的影响。结果表明：旋转反压会在压气机内形成前传压力波，其与扩压器和叶轮的叶片相互作用，形成复杂的波系结构。当旋转反压传播方向与叶轮旋转方向相反时，前传压力波的压力峰值在扩压器内先下降后上升，在进入叶轮通道后迅速下降，无法到达叶轮入口。当旋转反压传播方向与叶轮旋转方向一致时，压力波波形发生明显变化，其与扩压器叶片相互碰撞导致强度明显下降，向上游传播距离更短。

Abstract:

Since the rotating detonation combustor has the characteristics of self-pressurization and high thermal efficiency， replacing the combustor of aero-turbine engines with a rotating detonation combustor can further improve the engine performance. Based on the unsteady Reynolds-averaged Navier-Stokes method and the k-ε turbulence model， three-dimensional numerical simulations of the interaction between rotating backpressures and centrifugal compressor blades were conducted. The interaction between forward propagating waves caused by rotating backpressures and blades of the diffuser and the impeller was studied and the influence of the rotating backpressure propagation direction on the movement of forward propagating waves was analyzed. The results show that the rotating backpressure generates a forward propagating wave in the compressor， which interacts with blades of the diffuser and the impeller to form a complex wave system. When the rotating backpressure propagation direction is opposite to the impeller rotating direction， the peak pressure of forward propagating waves first drops and then rises in the diffuser， and drops rapidly after entering the impeller channel， unable to reach the impeller inlet. When the rotating backpressure propagation direction is consistent with the impeller rotating direction， the waveform of forward propagating waves changes significantly， and the collision with diffuser blades result in a significant decrease in intensity， with a shorter upstream propagation distance.