According to the thermodynamic process and the sound speed calculation models of the single/two-phase flow

a method with real gas is presented to design cylindrical mixing chamber ejectors. The entrainment ratios calculated by the proposed method match the experimental results relatively well with an error of ±17%. The proposed method predicts that there must be an optimal exit pressure of the mixing chamber corresponding to the maximum design entrainment ratio. The optimal reciprocal value of diffuser pressure ratio is introduced in order to determine the relationship between the optimal exit pressure of the mixing chamber and design conditions of ejectors conveniently and quickly. The relation curves of optimal reciprocal values of diffuser pressure ratios vs expansion and compression ratios for steam

ammonia

R290

R134a and R22 ejectors are calculated based on usual working conditions

and further the corresponding regression expressions are fitted. Those expressions can figure out the optimal reciprocal values of diffuser pressure ratios rapidly so as to obtain the optimal exit pressure of the mixing chamber

and thus a high efficient ejector can be designed.