设计马赫数下高负荷压气机叶栅流动损失的参数化调控

Parametric regulation of flow loss of a highly loaded compressor cascade in design Mach number

为有效预测、调控高负荷压气机平面叶栅的旋涡结构与流动损失,本文以某高负荷的可控扩散叶型(CDA)拉伸生成的平面叶栅为研究对象,采用数值计算方法、损失权重系数分析方法研究了在几何、气动变量条件下,叶栅流道内的旋涡结构与流动损失之间的关联性。揭示了稠度,安装角和进、出口几何角等参数变化影响旋涡结构损失与出口截面损失的作用机理,建立了相对完整的各几何参数影响流动损失及损失权重系数的参数化表达式。结果表明:根据参数化表达式来对不同参数下的最优解进行预测后,各单参数变量下对应的最佳优化结果平均绝对误差不超过3%,对于影响损失较大的几何参数的损失权重系数预测时,平均绝对误差不超过6%。通过本文所提出的参数化方法,与传统损失模型相比,在计算高负荷压气机叶栅流动损失方面的精度得到了显著提升,一些预测精度提升了一个数量级。本文以最佳参数预测、重构一套优化叶栅,实际数值计算结果表明,相较于原型叶栅,优化叶栅出口截面损失下降了11.18%,扩压能力提升了8.04%,达到了定性预测的目的。

To effectively predict and regulate vortex structure and flow losses in highly loaded pressurized cascades affected by vortices,this paper focuses on a cascade generated by stretching some controlled diffusion airfoil(CDA)in the highly loaded condition.Utilizing numerical calculation methods and loss weight coefficient analysis,the study investigates the correlation between vortex structure and flow losses in the cascade passage,considering both geometric and aerodynamic variables.The mechanisms by which changes in parameters,such as solidity,stagger angle,inlet,and outlet geometric angles,impact vortex structure losses and outlet cross-section losses are revealed.Additionally,comprehensive parametric expressions for flow losses and loss weights coeffi⁃cient influenced by each geometric parameter are established.The results demonstrate that when optimal solu⁃tions are predicted based on these parametric expressions,the average absolute error for each single-parameter variable is limited to 3%.For predicting the loss weights coefficient of geometric parameters with a greater impact on losses,the average absolute error is no more than 6%.The accuracy in calculating the flow losses in the cas⁃cade of a highly loaded compressor is significantly improved compared to the conventional loss model,some pre⁃diction accuracy is improved by an order of magnitude.Finally,this paper predicts and reconstructs an optimized cascade using the best parameters.Actual numerical calculations show that,compared to the prototype cascade,the optimized cascade exhibits an 11.18%reduction in outlet cross-section loss and an 8.04%increase in expan⁃sion capacity,achieving qualitative prediction goal.