For the purpose of further enhancing the performance of the cascade, this study takes the high-load diffuser cascade as the research object. By simplifying the design of the cascade with leakage flow in experiments, tests and numerical simulation were conducted at design incidence angle of 0° and the minimum loss incidence angle of -4° for different leakage flow rates and leakage inflow angles. The results show that changes in leakage flow rates and inflow angles will lead to variations in the momentum thickness of the boundary layer at the leading edge of the cascade, thereby affecting the cascade performance. Increasing the leakage flow rate results in an increase in the spanwise and tangential momentum of the leakage flow, a thickening in the axial momentum thickness of the boundary layer at the cascade leading edge, a reduction in the static pressure on the endwall within the cascade passage, a decrease in the expansion capability, and a raising in losses. Increasing the leakage inflow angle results in no change in the spanwise momentum of the leakage flow, an increase in the tangential momentum, a thickening in the tangential momentum thickness of the boundary layer at the cascade leading edge, a gradual increase in the static pressure at the leading edge, but a decrease in the static pressure within the cascade passage, leading to a decrease in the expansion capability. Changes in the tangential momentum of the leakage flow mainly affect the passage vortex, the trailing shedding vortex and the concentrated shedding vortex within the cascade passage.

中文翻译：

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泄漏流对高速扩散器级联性能影响机理的实验和数值研究


为了进一步提高级联的性能，本文以高负荷扩散器级联为研究对象。通过简化实验中泄漏流的复叠设计，针对不同的泄漏流速和泄漏流入角，在设计入射角为 0°、最小损失入射角为 -4° 的情况下进行了试验和数值模拟。结果表明，泄漏流速和流入角的变化会导致级联前缘边界层的动量厚度发生变化，从而影响级联性能。增加泄漏流速会导致泄漏流的翼展方向和切向动量增加，级联前缘边界层的轴向动量厚度增厚，级联通道内端壁上的静压降低，膨胀能力降低，损耗增加。增加泄漏流入角导致泄漏流的翼展向动量没有变化，切向动量增加，级联前缘边界层的切向动量厚度增厚，前缘的静压逐渐增加，但级联通道内的静压降低， 导致扩展能力下降。泄漏流切向动量的变化主要影响级联通道内的通道涡、尾部脱落涡和集中脱落涡。