A steady and unsteady numerical research is carried out to explore some effects of a specific non-axisymmetric tip clearance layout on the overall performance and stability of an axial compressor stage. For a 4-stage low-speed research compressor (LSRC) in Shanghai Jiao Tong University (SJTU), one-eighth annulus of the inlet guide vane and the first stage rotor was modeled for this study. After the validation for the uniform tip clearance case, a specific non-axisymmetric tip clearance layout is chosen from several random cases generated by the Gaussian Probabilistic Density Function method. Unsteady time-averaged results at the near stall condition show that the chosen non-axisymmetric layout can improve the isentropic efficiency by 1.3% and extend the stall margin by 4%. Detailed analyses on flow fields are carried out to interpret the performance improvement. Due to the circumferential layout of clearance sizes, the inlet mass flow and incidence are redistributed in both the radial and circumferential directions. It leads to blade loading and tip leakage flow varying with the tip clearance size. The quantification of blockage manifests that the blockage arising from the tip leakage flow is significantly alleviated in the non-axisymmetric layout, which leads to improvements in overall performance and stall margin. Transient flow fields at the rotor tip are also analyzed at the near stall condition. For the non-axisymmetric layout, low-momentum regions originating from larger clearance sizes oscillate and develop downstream in one blade passage period.

进行了稳态和非稳态数值研究，以探索特定的非轴对称叶尖间隙布局对轴流压缩机级整体性能和稳定性的一些影响。对于上海交通大学 (SJTU) 的 4 级低速研究压缩机 (LSRC)，本研究模拟了入口导叶和第一级转子的八分之一环。在对均匀叶尖间隙情况进行验证后，从高斯概率密度函数方法生成的几个随机情况中选择特定的非轴对称叶尖间隙布局。近失速条件下的非定常时间平均结果表明，所选择的非轴对称布局可将等熵效率提高 1.3%，并将失速裕度扩大 4%。对流场进行详细分析以解释性能改进。由于间隙尺寸的圆周布局，入口质量流量和入射在径向和圆周方向上重新分布。它导致叶片载荷和叶尖泄漏流量随叶尖间隙尺寸而变化。堵塞的量化表明，在非轴对称布局中，由尖端泄漏流引起的堵塞得到了显着缓解，从而提高了整体性能和失速裕度。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。由于间隙尺寸的圆周布局，入口质量流量和入射在径向和圆周方向上重新分布。它导致叶片载荷和叶尖泄漏流量随叶尖间隙尺寸而变化。堵塞的量化表明，在非轴对称布局中，由尖端泄漏流引起的堵塞得到了显着缓解，从而提高了整体性能和失速裕度。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。由于间隙尺寸的圆周布局，入口质量流量和入射在径向和圆周方向上重新分布。它导致叶片载荷和叶尖泄漏流量随叶尖间隙尺寸而变化。堵塞的量化表明，在非轴对称布局中，由尖端泄漏流引起的堵塞得到了显着缓解，从而提高了整体性能和失速裕度。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。它导致叶片载荷和叶尖泄漏流量随叶尖间隙尺寸而变化。堵塞的量化表明，在非轴对称布局中，由尖端泄漏流引起的堵塞得到了显着缓解，从而提高了整体性能和失速裕度。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。它导致叶片载荷和叶尖泄漏流量随叶尖间隙尺寸而变化。堵塞的量化表明，在非轴对称布局中，由尖端泄漏流引起的堵塞得到了显着缓解，从而提高了整体性能和失速裕度。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。转子尖端的瞬态流场也在接近失速状态下进行分析。对于非轴对称布局，源自较大间隙尺寸的低动量区域在一个叶片通过周期内振荡并向下游发展。