Abstract: he lobed nozzle and round nozzle experiments,both with the same exit areas,are in low pressure ratio ejector systems to investigate the pumping capability and mixing efficiency.And the 3-D flow fields inside the lobed nozzle ejector are measured.The results show that the ejector pumping capability and nuxing efficiency are obviously improved by using the lobed noz-zle which can generate large-scale axial vortiees and cause lower static pressure at the nozzle exit.

Key words: ejector, mixing flow, nozzle, lobed nozzle