Abstract: In order to reveal effects of the clocking arrangement on performance of high pressure ratio tandem centrifugal compressor, based on numerical simulation method validated by experimental data, the overall performance and flow field structures of the tandem impeller with typical clocking arrangements are analyzed. Results indicate that influence of the clocking arrangement on tandem impeller flow is mainly ascribed to the tip region of the rear impeller. The compressor stage performance is optimum with 75% clocking arrangement, while it is the worst with 25% clocking arrangement. The mechanisms of tandem design improving centrifugal compressor flow field include the blowoff effect of the airflow near inducer pressure surface on the boundary layer of exducer suction surface, and the ejection effect of the fluid near exducer suction surface on the wake of inducer blade. The design principle for the clocking arrangement of high pressure ratio tandem centrifugal compressors is to adopt a high value of the circumferential offset, on the premise of guaranteeing the wake of inducer blade not to directly interact with the exducer suction surface.

Key words: Centrifugal compressor;Tandem impeller;Clocking arrangement;Flow field characteristics;Numerical simulation

摘要： 为揭示周向布局对高压比串列离心压气机性能的影响机制，采用经试验数据确认的数值方法，对串列叶轮在典型周向布局下的性能及流场结构进行了分析。研究表明：周向布局对串列叶轮流动的影响主要体现在后排叶轮的叶顶区域， 75%周向位置时压气机级性能最优，25%周向位置时最差；串列叶轮改善离心压气机流场的物理机制为诱导轮压力侧气流对导风轮吸力面附面层的吹除效应，以及导风轮吸力面侧流体对诱导轮尾迹的引射效应；高压比串列离心压气机周向布局的优化应遵循的原则是，在避免诱导轮尾迹与导风轮吸力面发生直接作用的前提下，应采用较大的周向偏置参数。

关键词: 离心压气机;串列叶轮;周向布局;流场特性;数值模拟