Pressure distribution feature-oriented sampling for statistical analysis of supercritical airfoil aerodynamics

In the field of supercritical wing design, various principles and rules have been summarized through theoretical and experimental analyses. Compared with black-box relationships between geometry parameters and performances, quantitative physical laws about pressure distributions and performances are clearer and more beneficial to designers. With the advancement of computational fluid dynamics and computational intelligence, discovering new rules through statistical analysis on computers has beco...     

超临界二氧化碳多槽型干气密封泄漏流动与动力特性研究

针对超临界二氧化碳（SCO₂）旋转机械面临的严重泄漏、气流激振引发转子失稳等问题，以美国通用电气公司10MWe SCO₂循环中高压涡轮的轴端密封为研究对象，设计了螺旋角15°和30°的螺旋槽、T型槽和ST型槽的四种槽型结构的干气密封。采用基于动网格技术和非定常CFD数值方法的微尺度摄动模型，研究了在实验边界条件下干气密封的稳态性能及在轴向简谐微扰动下SCO₂涡轮轴端干气密封的非稳态动力学特性。对比分析了3种动压槽深度、2种动压槽角度下的干气密封泄漏量、静态气膜刚度、动态气膜刚度和阻尼系数。研究表明：四种槽型均满足泄漏流量的设计要求。随着动压槽深度的增加，干气密封开启力与泄漏流量均增大。ST型槽干气密封有着较大的气膜刚度和刚漏比，同时其在面对轴向微尺度摄动时最为稳定，是综合性能最优秀的干气密封结构。