An adjustable ejector with axial moving probe was taken as the object

the effects of ejector with supersonic and subsonic nozzles were investigated by experiment and simulation. The results showed that the flow characteristics of nozzles exit driving flow has close relationship with performance of the ejector

and was the main reason for the differences of the performance on the ejectors of two configurations of nozzles. For supersonic nozzles

the state of the nozzle exit's driving flow varies with the position of the probe

while the subsonic nozzle has no such variation characteristic. In the process of adjusting the performance of the ejector through the probe

when the supersonic nozzle exit's driving flow was ideally-expanded

the system was at an optimal operating condition. While the driving flow was over-expanded

the compression shock waves would be generated

the system performance would be reduced and its performance was inferior to the performance of subsonic nozzle. Furthermore

alternatives for two nozzle configurations were proposed.