In order to regulate critical flow rate of traditional critical flow Venturi nozzles

a new variable throatarea critical flow Venturi nozzle is proposed

throat area of which can be adjusted. Three different adjusting methods

including rod-style method

cone-style method and hybrid-style method

are analyzed by means of structure analysis

modeling calculation and fluid dynamics Fluent simulation. Results show that the critical flow of the new variable critical flow Venturi nozzles can be regulated well by using three different methods and when back-pressure ratio is smaller than the maximum allowable back pressure ratio

the flow rate of the new nozzle is almost kept constant

though the back-pressure ratio is still descending. And Fluent results coincides with the theoretical value calculated by modeling.