本文在兼顾变工况性能情况下对2.5级压气机高亚音级叶片进行气动优化。采用B样条曲线对压力面和吸力面厚度(8个控制点)、中弧线(4个控制点)进行参数化拟合,同时为了减少优化变量,将压力面和吸力面各8个厚度控制点位置以及大小处理为参考点的相对值。耦合自编优化算法与S1程序分别对第一级静叶和第二级静叶的三个截面进行气动优化,优化目标综合考虑了设计点损失、80%安全工作范围损失、近失速点损失、近堵塞点损失、设计点出气角。出于强度因素以及设计难度考虑,优化时对叶型面积和最大马赫数进行约束。三个所选截面叶型完成优化后通过插值获得叶根和叶尖叶型,通过重心积叠形成三维叶片。在三维详细造型中对出口几何角进行微调,使得三维计算的出气角与原型更加匹配,并和优化前叶片一样增加相同尺寸倒圆设计。最终对优化后2.5级压气机进行设计转速特性线进行三维数值模拟,结果表明设计点效率以及堵塞流量、喘振裕度均得到提高,尤其是喘振裕度由4.8%大幅增加到13.8%。

This paper conducts an aerodynamic optimization of high-subsonic stators for a 2.5-stage compressor while taking into account the performance under variable conditions. B-spline curve is used to parametrically fit the thickness of the pressure and suction sides (with 8 control points each) and the mean camber line (with 4 control points). To reduce the number of optimization variables, the positions and sizes of the 8 thickness control points on both the pressure and suction surfaces are treated as relative values to the reference point. A self-developed optimization algorithm is coupled with the S1 program to perform aerodynamic optimization on three sections of the stator 1 and stator 2. The optimization objectives take into account loss at the design point, loss within the 80% safe operating range, loss of near stall point, loss of near chock point, and outlet angle at the design point. Considering strength factors and design complexity, constraints are imposed on area of the airfoil and maximum Mach number during optimization. After optimization of the three selected sections is completed, the root and tip blade profiles are obtained through interpolation, and a three-dimensional blade is obtained by stacking the centroids. In the three-dimensional detailed modeling, the outlet geometric angle is fine-tuned to better match the outlet angle with the original one calculated in three-dimensional numerical simulation, and the same size fillet design is added as the original one. Finally, a three-dimensional numerical simulation of the design speed characteristic line of the optimized 2.5-stage compressor is carried out, and the results show that the efficiency at the design point, as well as the chocked mass flow and surge margin, have been improved, especially the surge margin, which has increased significantly from 4.8% to 13.8%.

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