跨声速压气机实验系统Helmholtz频率的影响因素及估算方法研究

针对压气机实验系统 Helmholtz共振频率的研究对于建设压气机试验系统及研究压气机流动不稳定现象均有重要意义。以北京航空航天大学跨声速压气机试验系统为背景,通过拆除该压气机试验系统的稳压箱、格栅等部件以及更改该试验系统的几何尺寸,分析该型压气机试验系统 Helmholtz 共振频率的影响因素;同时引入了Duct-Compressor-Plenum模型理论,对该压气机试验系统进行相应的模化,并对其系统 Helmholtz 共振频率进行相应估算。结果表明:在该类型的跨声速压气机试验系统中,压气机前端的稳压箱及稳压箱之前部分主要作用是为整个试验系统提供均匀的进气环境,而对系统 Helmholtz 共振频率不产生任何影响。因此,在跨声速压气机试验系统Duct-Compressor-Plenum模型模化过程中,不应将稳压箱及其之前部件进行模化。

Study on influencing factors and estimation method of Helmholtz harmonic frequency in transonic compressor test system

Compressor testing facility is one of the fundamental and imperative experimental apparatus when carrying out experiments to investigate phenomena occurring within the compres-sor.In this paper,experiments have been carried out on the complex transonic compressor tes-ting facility in Beihang University to analyze the influence of the systematic Helmholtz harmonic frequency on this specific testing facility.Several modifications have been made to this compres-sor testing facility in Beihang University to accommodate the experiments.Firstly,the settling chamber,screen and other parts have been removed from this testing facility.In addition,the geometry of the compressor testing facility has been adjusted for this experiment.Modified compressor testing facility has been modeled using Duct-Compressor-Plenum model theory;cal-culations on estimating the effect of the systematic Helmholtz harmonic frequency have been con-ducted and investigated.Final results indicate that the settling chamber at the inlet cannot affect the systematic Helmholtz harmonic frequency,but can improve the uniformity of the flow and minimize the turbulence level.It can be concluded that the Duct-Compressor-Plenum model should not be applied to the testing facility when conducting experiments on it.