不同条件下平面叶栅风洞流场品质的实验研究

为了全面认识亚声速平面叶栅风洞的流场品质及其影响因素,以典型高亚声速平面叶栅风洞为研究对象,试验测量并分析了空风洞的来流品质以及安装叶栅试验件后来流马赫数、来流攻角、以及叶片数对叶栅进口准确性、均匀性以及出口周期性的影响.研究结果表明:空风洞内主流区域宽广且基本均匀,来流马赫数偏差不超过±0.005,来流气流角偏差不超...

Experimental Study on Flow Field Quality of Linear Cascade Wind Tunnel under Different Conditions

In order to fully understand the flow quality of the subsonic linear cascade wind tunnel and its influencing factors, based on the high subsonic cascade wind tunnel of NPU, experimentally measured and analyzed of the flow quality were performed with and without cascade, and the effects of the inlet Mach number, the incidence and the number of blades on the accuracy, uniformity and periodicity of pitchwise are studied. The results show that the main flow of empty wind tunnel is broad and basically uniform, the Mach number deviation is no more than ±0.005, and the flow angle deviation is no more than ±1. The pithwise distribution of cascade flow shows asymmetry, mainly because the poor flow uniformity and accuracy upstream of the three blade passages near the upper movable sidewall, while the blade passages from middle to lower sidewall show good flow quality. The incidence shows larger influence on the flow quality than inlet Mach number. The inflow shows good quality at a negative or smaller positive incidence. While the inflow is encountered with poor quality at a large positive incidence. And the flow uniformity and accuracy upstream of the cascade can directly affect the flow periodicity in the blade passages and downstream of the cascade.