级间进出口几何角度对压气机气动性能和封严效果的影响

为了削弱级间泄漏流对压气机性能的不利影响,提出了一种基于Coanda型几何进出口的级间结构,并以一个亚声速单级轴流压气机为研究对象,数值模拟了5°,10°,20°三种不同级间进出口几何角度对压气机性能的影响。结果表明:改进后的级间进出口几何结构使得压气机流量和效率均略有提升。分析原因是级间出口泄漏流以较小角度与主流汇合,增大了静叶进口气流的轴向速度、径向速度,使得静子通道流动堵塞程度减轻,总压损失减小,扩压能力增强。同时,新结构还减小了级间泄漏流的流量系数,改善了级间封严效果。5°,10°,20°角度下的压气机效率最大分别提升了0.68%,0.63%,0.62%。

Influence of Geometric Angle of Inter-Stage Inlet and Outlet on Aerodynamic Performance and Sealing of Compressor

In order to reduce the influence of leakage flow at the inter-stage gap on the aerodynamic performance of the compressor, a new type of inter-stage gap based on Coanda geometry is proposed. The gap structures with different injection angles of 5o, 10o and 20o are designed, and a subsonic single-stage axial flow compressor is used for numerical simulation. Results show that mass flow rate and isentropic efficiency of the compressor are slightly increased by the improved inter-stage structure. The reason for the analysis is that the leakage flow of the inter-stage outlet merges with the main flow of the compressor at a smaller angle, which increases the axial and radial velocity of the stator passage, so that the flow blockage of the stator passage is weakened, the total pressure loss is also reduced, and the diffuser capability of stator passage is enhanced. At the same time, the new structure also reduces the discharge coefficient of inter-stage leakage flow and improves the sealing effect. The isentropic adiabatic efficiency of the single stage compressor at three angles rise by 0.68%, 0.63% and 0.62% respectively at the maximum.