为开展串列叶栅优化设计，发展了基于中弧线叠加厚度分布的串列叶栅参数化造型方法，搭建了基于Kriging代理模型和NSGA-Ⅱ优化算法的串列叶栅多目标优化设计平台。以某多级轴流压气机末级静叶叶中截面54.15°大弯角叶型为原型，开展了串列叶栅改型和多目标优化设计。串列叶栅几何参数敏感性分析结果表明，前排叶型安装角、轴向重叠度、周向节距和弯角比四个参数对串列叶栅气动性能影响最为显著。与原型单列叶栅相比，优化串列叶栅轴向长度缩短，相同冲角下总压损失降低、静压比提高，可用冲角范围拓宽33.3%，在-12°、-2°和4°冲角下总压损失分别降低39.1%、3.3%和11.9%。优化串列叶栅前排叶型负荷降低、后排叶型负荷增大，合理的缝隙结构可以削弱/抑制边界层分离，可在全冲角范围内提升叶栅气动性能。

In order to carry out the optimization design of tandem cascade, the parametric modeling method of tandem cascade based on superimposing thickness on camber line is developed, and the multi-objective optimization design platform of tandem cascade based on Kriging surrogate model and NSGA-Ⅱ optimization algorithm is constructed. The high-turning blade profile with camber angle of 54.15° from the mid span of the last stage stator of a multi-stage axial compressor is taken as the prototype to perform the multi-objective optimization design of tandem cascade. The sensitivity analysis of geometric parameters of tandem cascade shows that the stagger angle of forward airfoil, axial overlap, circumferential percent pitch and camber angle ratio have the most significant influence on the aerodynamic performance of tandem cascade. Comparing with the prototype cascade, the axial length of the optimized tandem cascade is shorter. The total pressure loss coefficient of the optimized tandem cascade is smaller and the static pressure ratio is larger than those of the prototype cascade at the same incidence angle. The available working range of the optimized tandem cascade is increased by 33.3%, and the total pressure loss coefficient is decreased by 39.1%, 3.3% and 11.9% at incidence angle of -12°, 2° and 4° respectively. For the optimized tandem cascade, the load of forward airfoil is decreased and the load of aft airfoil is increased, the reasonable gap shape can weaken/suppress the boundary layer separation, thus the aerodynamic performance within the full incidence range is increased.

国家科技重大专项（2017-II-0007-0021, 2017-II-0006-0020）