分流叶片长度和周向位置对高压比离心压气机性能的影响

Effects of Splitter Blade Length and Circumferential Position on Performance of High Pressure Ratio Centrifugal Compressor

关键词:  离心压气机  分流叶片  周向位置  叶片长度  流场特性

Key words:  Centrifugal compressor  Splitter blade  Circumferential position  Blade length  Flow field characteristics

摘要:

为揭示分流叶片长度和周向位置对高压比离心压气机性能的影响机制，采用数值方法考察了典型分流叶片长度和周向位置下压气机性能和流场结构。通过对压气机流场的详细分析，建立了分流叶片长度和周向位置参数与压气机流动结构的关联性。研究表明：分流叶片的优化设计需综合考虑长度和周向位置，采用60%长度和60%周向位置的分流叶片方案可获得最佳压气机级性能，该方案的压比和效率较设计值分别提高了3.2%和1.0%；分流叶片改善压气机性能的机制为分流叶片对主叶片泄漏涡的分流作用，以及分流叶片吸力面高速低压气流对泄漏涡的引射作用；进行分流叶片优化设计时，应合理选取叶片长度和周向安装位置，以实现分流叶片对主叶片泄漏涡的分流和引射，同时应避免分流叶片过长导致叶顶发生明显二次泄漏和分流叶片前缘形成高马赫区。

Abstract:

To reveal the effects of splitter blade length and circumferential position on performance of high pressure ratio centrifugal compressor， numerical method was used to analyze performance and flow structures of the compressor with typical splitter blade lengths and circumferential positions. Based on the detailed analysis of flow fields in the compressor， the relationships between compressor flow structures and parameters of splitter blade length and circumferential position were established. Results indicate that both length and circumferential position should be taken into consideration for the optimization design of splitter blade. The optimal compressor stage performance can be achieved with the splitter blade case of 60% length and 60% circumferential position， which improves the pressure ratio and efficiency by 3.2% and 1.0% than the design values， respectively. The mechanisms of splitter blade improving compressor performance are the split effect of splitter blade on the main blade leakage vortex， and the ejection effect of the high speed and low pressure airflow near splitter blade suction surface on leakage vortex. In the process of splitter blade optimization， the blade length and circumferential position ought to be reasonably selected to realize the split and ejection effects of splitter blade on the main blade leakage vortex. In the meantime， overlong splitter blade should be avoided， which may cause significant tip secondary leakage and high Mach region around the leading edge of splitter blade.