Abstract: Experimental research for seven combinations of four two dimensional(2 d) lobed nozzles with two 2 d mixing tubes of exhaust ejector systems has been conducted to investigate the effect of the lobe structure on the aerodynamic performance of the ejector systems. Test results show that 2 d staggered lobed nozzles have better pumping and mixing enhancement ability than the 2 d aligned lobed nozzles, but they also cause bigger pressure loss; the 2 d lobed nozzles with equal lobe width have better aerodynamic performance than the 2 d lobed nozzles with internal width equal to two times the external width. The 2 d scalloped staggered lobed nozzle has the best pumping and mixing enhancement performance, but it also has the biggest pressure loss coefficient. Among the experimental model combinations, the combination of 2 d lobed nozzle with equal lobe width and 2 d mixing tube with multiple ring cooling structure has the best aerodynamic performance.

Key words: ejectors, jet exhaust, jet mixing flow