Furthermore, the study of the TSE performance in the gas/gas ejector system compared with the SSE simulations using CFD showed that when the primary inlet pressure was 4 bar and secondary inlet pressure was 1 bar. The TSE provided a marginal decrease entrainment ratio of 3.73% but increased critical back pressure of 35.92%. It was found that the predicted performance of the CFD simulated models were agreed well with the experimental values. Average errors of the predicted entrainment ratio and the critical back pressure were 18.54% and 2.00%, respectively.