转静盘腔流动瞬态响应特性研究

以航空发动机转静盘腔内非稳态流动为研究对象,基于用户自定义函数编程设置进口压力按斜坡函数变化时的非稳态边界条件,利用数值模拟方法,在滞后效应、流场演化和物性参数方面,研究了不同无量纲跃升幅值下转静盘腔流动瞬态响应机理。结果表明:无量纲跃升幅值由1.05增至1.2,盘腔内部的当地响应时间延长了81.1%,相对总温的超调量增加了157.0%,其峰值时间增加了31.3%,且进口压力波动的传播方向总是由进口指向出口;瞬态过程中,转静盘腔的容积效应和旋转效应共同作用使出口流量明显滞后进口流量,且其滞留质量流量与相对总温的超调现象密切相关;冲击射流、旋转贴壁射流和静子壁面侧的涡系构成了盘腔流场演化的主体,无量纲跃升幅值越大,流场演化过程越剧烈,响应时间越长;声速和热扩散率与盘腔响应速度密切相关。

Investigation on Transient Response Characteristics ofFlow of Rotor-Stator Cavity

The unsteady flow of the aero-engine rotor-stator cavity as the research object, the unsteady boundary conditions were set when the inlet pressure changes followed the ramp function were programmed based on the user-defined function programming. The unsteady state numerical simulation was carried out to investigate the transient response characteristics of rotor-stator cavity under different dimensionless jump coefficient, which was within the perspective of the hysteresis effect, flow field evolution and physical properties. The results show that the local response time inside the disk cavity is extended by 81.1%, the overshoot of the relative total temperature increased by 157.0%, the peak time increased by 31.3% when the dimensionless jump amplitude increases from 1.05 to 1.2. The propagation direction of the undulation of inlet is always from the inlet to the outlet. In the transient process, the combination effect of the volumetric and rotational effects of rotor-stator cavity causes the outlet flow to significantly lag behind the inlet flow, and the overshoot of relative total temperature is closely related to the mass flow storage in cavity. The impinging jet, the rotating adhering jet and the vortex on the side of the stator wall constitute the main body of the evolution of the disk cavity flow field, and the larger the dimensionless jump coefficient, the more intense the flow field evolution process, and the longer the response time is. The response speed is closely related to the sonic speed and the thermal diffusivity.