某型压气机低转速特性扩展方法对比分析

采用指数外插法在相近低转速时,通过发动机状态相似的假设得到部件特性,而能量外推法从能量损失的角度出发,通过发动机在自模化区的流动特点进行低转速特性外推。为验证能量外推法的可行性,在某型涡扇发动机高压压气机试验台上开展转速调试试验,录取高压压气机在不同转速下的性能数据并进行分析,得到改型发动机的高压压气机特性。根据经验,试验时最低相对换算转速只能达到0.5,采取2种外推方法对低转速特性进行外推。结果表明:能量外推法相比于指数外推法具有可行性好、准确度高的特点,在实际发动机研制过程中实用性更强。

Comparative Analysis of Index Expansion Method for Low Speed Characteristics ofCertain Compressor

The component characteristics was obtained through similar hypothesis of engine state by using Index Expansion Method(IEM)based on near low rotate speed. However, Parabolic Expansion Method (PEM) was based on the energy loss, which the characteristicsexpansion of low speed was performed by the engine flow characteristics in mould area. In order to verify the feasibility of PEM, the speedtest was performed on test bed of high-pressure compressor for a turbofan engine. The performance data at different rotate speed of highpressurecompressor were recorded and analyzed, and the characteristics of high pressure compressor for modified engine was obtained.Based on experiences, the lowest relativity corrected speed was only to 0.5 when the test was performed. The characteristics of low speedwere expanded by using two methods. The results show that comparing with PEM, IEM has good feasibility, high accuracy and practicabilityin practical engine development.