压力畸变对某三级风扇性能影响研究

Effects of Pressure Distortion on Performance of Three Stage Fan

关键词:  挡板  压力畸变  风扇  数值仿真  温度畸变

Key words:  Flat baffle  Pressure distortion  Fan  Numerical simulation  Temperature distortion

摘要:

采用挡板产生压力畸变，以三级风扇为平台研究风扇抗畸变性能。试验结果表明，畸变敏感系数随换算转速的变化与畸变指数相关，不同畸变指数下风扇畸变敏感系数并不唯一，最大变化量超过40%。依据试验结果，分析畸变指数、稳态与动态畸变指数比例、畸变敏感系数、畸变衰减等随换算转速或挡板堵塞比的变化规律，初步探讨了风扇特性线形状对其抗压力畸变能力的影响。基于试验结果，针对三级风扇开展了15%挡板堵塞比下的数值仿真研究，初步研究了压力畸变的产生过程及压力畸变在风扇内部衰减并产生温度畸变的过程。数值仿真结果表明，设计转速工作点第一级转子出口总温不均匀性大于15%。

Abstract:

Total-pressure distortion was produced by flat baffles. Test was conducted on a 3-stage fan and the influence of the flat baffle on the fan was researched. The test results show that the variation of sensitivity coefficient of distortion with rotational speed is related to the distortion index and the sensitivity coefficient of distortion is not unique under different distortion index， the biggest variation is greater than 40%. Based on the test results， variation of the distortion index， the proportion of steady and unsteady distortion index， the sensitivity coefficient of distortion， and the attenuation of distortion with rotational speed or blockage ratio were discussed. The influence of the shape of the fan characteristic line on the ability to resist pressure distortion was preliminarily discussed. Based on the test results， numerical simulation was conducted on a 3-stage fan with a flat baffle which blockage ratio is 15%， the generation and attenuation of the pressure distortion and the generation of the temperature distortion in the fan were preliminarily researched. The numerical simulation shows that the uniformity of total temperature on the outlet of the first rotor is greater than 15% at work-point of design rotational speed.