不同条件下平面叶栅风洞流场品质的实验研究

In order to fully understand the flow quality of the subsonic linear cascade wind tunnel and its influencing factors, based on a typical high subsonic cascade wind tunnel, the cascade wind tunnel flow quality were measured and analysed with and without cascade and the effects of the inlet Mach number. The incidence and the number of blades on the inflow accuracy, uniformity and outflow periodicity were studied. The results show that the main flow of empty wind tunnel is broad and basically uniform, the inlet Mach number deviation is no more than ±0.005, and the inlet flow angle deviation is no more than ±1°. After installing the test cascade, the pithwise distribution of cascade flow shows asymmetry, mainly due to 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, and the inflow of cascade shows good quality at a negative or smaller positive incidence, while the inflow of cascade is encountered with poor uniformity and accuracy at a large positive incidence. And the inflow uniformity and accuracy of cascade can directly affect the flow periodicity within the blade passages and downstream of the cascade.