Flow Control on Bowed Compressor Cascades Using Vortex Generator Jet at Different Incidences

Abstract

Vortex generator jets (VGJs) have been used to suppress the flow separations in bowed compressor cascades at different incidences via numerical calculations. The results show that with momentum injection and streamwise vortex produced by VGJ, the total losses in the bowed blades effectively decrease whereas the static pressure ratios increase. For the positively bowed blade, at −5° incidence, with slight flow separation, the mixing loss caused by VGJ is dominant and the loss increases by 1%; with an incidence ranging from 0° to +5°, the regions of the flow separations all decrease, and the total losses decrease by 2.7 and 5.4%, respectively; with the incidence increasing to +7°, the separation type converts from closed to open, and the loss decreases by 6.8%; when the incidence is +10°, one concentrated shedding vortex disappears, and the loss decreases by 9.27%. For the negatively bowed one, as the incidence increases from −5° to +7°, the flow separations are all effectively suppressed when all the separation types are closed, and the losses decrease by 2.9, 9.1, 17.5, and 19.75%, respectively. When the incidence increases to +10°, however, because of the huge range of flow separation, there is no improvement in the flow field, but the total loss increases by 1.37%.