低位预旋进气转静系盘腔流动特性研究

Study of Flow Dynamics in Rotor-Stator Cavity with Low-Radius Preswirl Inlet

采用实验和数值模拟的方法对低位预旋进气转静系盘腔的流动特性进行研究,考察了流量与动盘转速变化对腔室内流动的影响,结果表明腔内径向静压差随流量增大而增大,随转速升高而增大;引入腔内有效角动量的概念,用角动量系数表征其与盘腔入口角动量之比,通过分析来流角动量与盘面转矩的相对大小,推导得到影响角动量系数的两个主要无量纲参数为修正的湍流流动参数与预旋来流雷诺数;对于给定结构形式的预旋系统,当改变转速时,角动量系数随修正湍流流动参数增大而减小,当修正的湍流流动参数大于0.0646时,角动量系数变化缓慢,腔内有效角动量约为入口角动量的70%~90%;当改变来流速度时,角动量系数随修正湍流流动参数增大呈现先减小后增大的变化趋势.

The flow dynamics in rotor-stator cavity with low-radius pre-swirl inlet was investigated both ex-perimentally and numerically. The effects of flow rate and rotation speed on flow in the cavity were studied , and the results show that the rise of static pressure through cavity increased with flow rate and rotation speed. The con-cept of effective angular momentum was introduced,the ratio of which to angular momentum at cavity inlet is de-fined as angular momentum coefficient, and by analyzing the relative magnitude of angular momentum at inlet and work done by disk torque, it is found that the corrected turbulent flow parameter and the pre-swirl inlet Reynolds number were the two main nondimensional parameters affecting angular momentum coefficient. Given the geometry of pre-swirl system, when the rotation speed changed, angular momentum coefficient decreased with the increase of corrected turbulent flow parameter,and when corrected turbulent flow parameter was larger than 0.0646, angular momentum coefficient changed slowly, and the effective angular momentum was about 70%~90%of the inlet angular momentum. When the inlet velocity changed,angular momentum coefficient first decreased and then increased with the increase of corrected turbulent flow parameter.