Effects of an unsteady end-wall pulsed jet on a highly loaded compressor cascade at different incidence angles

We report work done to investigate the adaptability of the end wall unsteady pulsed jet (UPJ) at different incidence angles. In this research, the influence of the UPJ on the cascade aerodynamic performance at different incidence angles was systematically studied using validated numerical simulation methods. A comparative analysis using a traditional steady constant jet (SCJ) was also carried out. The numerical results show that the control effect of the UPJ is significantly superior to that of the SCJ for the design incidence angle, and the same for the time-averaged jet flow. When the time-averaged jet flow ratio ms 1/4 0.28% and the actuation frequency F+ = 0.80, a maximum total-pressureloss coefficient reduction of 28.66% and a static-pressure-rise coefficient increment of 13.17% are obtained. Compared with the SCJ, the loss for a cascade with the UPJ is decreased by 25.65%, and the static-pressure-rise coefficient is increased by 10.54%. For variable incidence angle, the UPJ can diminish the cascade loss for the range of incidence angle i from -8 degrees to +4 degrees and can improve the cascade aerodynamic performance to the greatest extent near i = 0 degrees. The SCJ shows excellent adaptability when the incidence angle is negative, but worsens the cascade performance at large positive incidence angles.