转子叶尖优化改型对轴流压气机级性能及流场影响

Effects of Rotor Tip Airfoil Optimization on Performance and Flow-Field of an Axial-Flow Compressor Stage

为探索转子叶尖叶型对轴流压气机叶尖端壁区域流动的影响,进一步改善轴流压气机性能,采用近似函数与遗传算法相结合的优化方法,针对1/2+1级轴流压气机在级环境下进行转子叶尖叶型优化设计,并对优化前后轴流压气机级流场进行对比分析。结果表明:转子叶尖优化改型后,轴流压气机级效率提升0.77%,设计转速下全工况范围内效率、压比均得到显著提高;该压气机效率的提高主要得益于叶型损失和泄漏流损失的降低,优化改型后的叶型更能适应叶尖区域的高亚声来流,转子叶尖激波被有效抑制,叶尖泄漏流减弱,叶尖端壁区域流动明显改善。

In order to investigate the effects of rotor tip airfoil optimization on the shroud endwall flow-field of axial-flow compressor and to improve the performance of the compressor,an optimization algorithm of combined approximate function method and genetic algorithm is adopted on the optimization of the rotor tip airfoil of an axial-flow compressor. The optimization is done under the stage environment of the 1/2＋1 stage axial-flow compressor. The performance and the flow-field of both the baseline compressor and the optimized compressor are investigated. It indicated that the stage efficiency of the compressor improves by 0.77% at the optimization point. The efficiency and the total pressure ratio of the compressor increase at the whole operating condition of the design rotating speed. The reason of the performance improvement is the decrease of the airfoil loss and the tip leakage flow loss. The optimized airfoil can be more suitabe to the high subsonic flow of the rotor tip. The results show that the normal shock of the rotor tip passage is effectively weakened by the optimized airfoil. Moreover,the rotor tip leakage flow is also weakened. As a result,the flow-field at the shroud endwall improves.