单级轴流压气机周向槽与梯状间隙结构的对比

在验证了计算模型的可靠性后,对单级轴流亚音压气机进行了71%设计转速下,实壁机匣,周向槽机匣与梯状间隙结构工作特性的数值模拟。结果表明,周向槽机匣与梯状间隙结构都能在一定范围内起到扩稳作用。周向槽的作用更多地体现在对叶片前缘叶顶泄漏涡的控制上,因此更适于设计在叶片通道的前半段。梯状间隙结构在叶片通道前半段与后半段都能起到扩稳作用,只是施于叶片前缘时,压气机效率损失较大,而施于叶片尾缘时,可以减小叶片尾迹分离区的面积,对提高压气机效率有益。

A Comparison of Circumferential Slot With Stepped Clearance Structure in a Single-stage Axial-flow Compressor

After the reliability of a calculation model has been verified,a numerical simulation for a single-stage subsonic axial-flow compressor was conducted of the working characteristics of a real wall casing,circumferential slot one and stepped clearance structure under the condition of 71% design speed.The simulation results show that both the circumferential slot casing and stepped clearance structure can enlarge the compressor stable operating range to a certain extent.However,the circumferential slot plays a more explicit role in controlling the blade tip leakage vortexes in the blade leading edge,thus making it more suitable to be designed at the front half portion of a blade flow passage.The stepped clearance structure can fulfil its due function of diffusion stabilization when located in both the front and rear half portion of the blade flow passage.When the above structure is allocated in the leading edge of a blade,the compressor will suffer a relatively large drop in efficiency.In case the clearance structure is located in the blade trailing edge,it can contribute to a reduction of the area of the separation zone in the blade wake,thus playing a beneficial role in enhancing compressor efficiency.