离心压气机无叶扩压器旋转失速诱发的能量损失机制研究

Mechanism of Energy Loss Induced by Rotating Stall in Vaneless Diffuser of Centrifugal Compressor

利用ANSYS软件分别对带宽、窄无叶扩压器的离心压气机进行数值模拟,研究了在旋转失速诱发过程中离心压气机无叶扩压器的流场分布及能量损失机制。研究表明,窄无叶扩压器失速诱发时盘盖侧边界层发生局部回流并在叶高方向向内延伸,而宽无叶扩压器失速与扭曲的核心流和回流混合密切相关。随着流量的减小,扩压器内能量损失逐渐增加,旋转失速发生后,能量损失快速增加,到失速完全发展时,达到最大,且宽无叶扩压器的能量损失大于窄无叶扩压器。窄无叶扩压器失速诱发点处存在性能曲线的不连续现象,分析了宽、窄无叶扩压器旋转失速诱发过程中的能量损失机制。

The flow field distribution and energy loss mechanism of vaneless diffuser in centrifugal compressor induced by rotating stall were studied by using ANSYS software.The results show that local backflow occurs in the boundary layer near the disk cover and extends inward in the direction of blade height when stall is induced by narrow vaneless diffuser,and the stall of wide vaneless diffuser is closely related to twisted core flow and backflow mixing.With the decrease of the flow rate,the energy loss in the diffuser increases gradually.After the rotating stall occurs,the energy loss increases rapidly and reaches the maximum when the stall develops completely.The energy loss of wide vaneless diffuser is greater than that of narrow vaneless diffuser.There is a discontinuity of the performance curve at the stall induced point of the narrow vaneless diffuser.The energy loss mechanism of the wide narrow vaneless diffuser during the stall induction process is analyzed.