旋转爆轰波与涡轮平面叶栅相互作用数值模拟

Numerical Simulation of Interaction Between Rotating Detonation Wave and Turbine Plane Cascade

关键词:  旋转爆轰燃烧室  涡轮平面叶栅  反射激波  压力振荡衰减  数值模拟

Key words:  Rotating detonation combustor  Turbine plane cascade  Reflected shock wave  Pressure oscillation attenuation  Numerical simulation

摘要:

由于旋转爆轰燃烧室具有自增压特性，可提高热力循环效率，因此将旋转爆轰燃烧室应用于燃气轮机可进一步提高系统的性能。基于非稳态雷诺时均Navier-Stokes方法，采用剪切应力输运k-ω湍流模型，建立旋转爆轰燃烧室与涡轮平面叶栅耦合计算模型，研究旋转爆轰燃烧室内的复杂波系与涡轮叶片的相互作用，分析涡轮叶栅对高频爆轰压力振荡的抑制作用。结果表明：旋转爆轰燃烧室内的燃气在涡轮叶栅内加速，并且在斜激波后的局部区域马赫数的增加更为明显。斜激波与涡轮静转子叶片的前缘、压力面、吸力面以及尾缘相互作用，由于旋转爆轰波不同的传播方向，使得斜激波与静子叶片呈相互垂直或平行，进而形成两种不同的波系结构。涡轮叶栅对高频压力振荡存在明显的抑制作用，涡轮叶栅上下游高频压力振荡幅值的衰减率达到80%以上。研究结果展示了旋转爆轰波作用下涡轮叶栅内复杂波系结构特征，并对基于爆轰燃烧推进技术的应用提供了一定的理论基础。

Abstract:

The rotating detonation combustor has the characteristic of self-pressurization， which can significantly improve the thermal cycle efficiency. Therefore， applying detonation combustion technology on gas turbine can further improve the system performance. In this research，a coupling calculation model of rotating detonation combustor and turbine cascade， based on the method of unsteady Reynolds-averaged Navier-Stokes and the k-ω turbulence model of shear stress transfer， was built up to study the interaction between rotating detonation wave and turbine cascade and analyze the suppression effect of turbine cascade on high frequency detonation pressure oscillation. The results show that the subsonic gas flow in the combustor was accelerated by the turbine cascade， and the Mach number of the local area behind the oblique shock wave increased more obviously. The oblique shock wave interacted with the leading edge， pressure surface， suction surface and trailing edge of the turbine’s stator vanes and rotor blades. Due to the different transport directions of rotating detonation waves， the oblique shock waves were perpendicular or parallel to the stator vanes and two different wave structures were formed. It was obvious that the turbine cascade can suppress the high frequency pressure oscillation， and the amplitude attenuation rate of high frequency pressure oscillation in the upstream and downstream of turbine cascade can be up to 80%. The results of the study have shown the structural characteristics of complex wave system in turbine cascade under the action of rotating detonation wave， and provided a theoretical basis for the application of detonation combustion propulsion technology.