Effects of modification on jet mixing of sword alternating lobed nozzle

A novel lobed nozzle named as sword alternating lobed nozzle was designed, combined with the characteristics of the existing alternating lobed nozzles to modify the baseline lobed nozzle. The effects of scalloping and scarfing on jet mixing of sword alternating lobed nozzle were investigated by numerical method. The results show that when the degree of scalloping or scarfing enhanced, the mixing in the downstream region of the lobe peak is accelerated, however the center primary flow needs a longish journey to be mixed. Scarfing has more capacity on promoting mixing than scalloping. Pumping performance and flow loss change little with scalloping whereas decrease slightly with scarfing. The results also indicate that the form of streamwise vortices has higher influence on mixing efficiency compared with the intensity of streamwise vortices.