The pressure matching and recovery performances of the second-throat supersonic-supersonic ejector have been performed experimentally and numerically in the current study.Schlieren pictures of flow structure in former...The pressure matching and recovery performances of the second-throat supersonic-supersonic ejector have been performed experimentally and numerically in the current study.Schlieren pictures of flow structure in former part of the mixing chamber with varied stagnation pressure ratio of the primary and secondary flows have been taken,and the maximum compression ratios have been obtained.Additionally,the relevant numerical simulations have been performed.The obtained results show that the pressure matching performance of the second-throat supersonic-supersonic ejector is weaker than that of the constant area one,and the pressure recovery performance of the former is better than that of the latter.For the ejectors tested in this paper,the stagnation pressure ratios of the second-throat supersonic-supersonic ejector at the limiting condition are approximately 10% lower than those of the constant area one when the contraction angle of the mixing chamber is 4°,and the maximum compression ratio is 12%-30% higher.When the contraction angle of the mixing chamber is 6°,the pressure matching performance of the second-throat supersonic-supersonic ejector declines sharply,and the pressure recovery performance remains almost the same.When the contraction angle of the mixing chamber is 8°,the supersonic-supersonic ejection phenomenon does not take place any longer.展开更多
The effect of the secondary flow on the starting pressure of a second-throat supersonic ejector has been investigated by adapting the height of the secondary flow inlet.The obtained results show that an optimum value ...The effect of the secondary flow on the starting pressure of a second-throat supersonic ejector has been investigated by adapting the height of the secondary flow inlet.The obtained results show that an optimum value of the secondary inlet height exists,and the starting pressure of the ejector becomes a minimum at that condition.Based on the results of the pressure measurements,a qualitative analysis has been made to clarify the flow behavior and the physical meaning of the performance diagram.It appears that the choking phenomenon of the secondary flow plays an important role in the starting process of the ejector.When the secondary inlet height is relatively small,the choked secondary flow and the supersonic primary flow could be employed to protect the static pressure in the suction chamber from being disturbed by the back pressure effect at a certain primary stagnation pressure,which is lower than the starting pressure for the case of the zero-secondary flow.However,as the secondary inlet height increases and exceeds a critical value,the static pressure in the suction chamber rapidly increases,and the starting pressure of the ejector increases accordingly.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 11172324)
文摘The pressure matching and recovery performances of the second-throat supersonic-supersonic ejector have been performed experimentally and numerically in the current study.Schlieren pictures of flow structure in former part of the mixing chamber with varied stagnation pressure ratio of the primary and secondary flows have been taken,and the maximum compression ratios have been obtained.Additionally,the relevant numerical simulations have been performed.The obtained results show that the pressure matching performance of the second-throat supersonic-supersonic ejector is weaker than that of the constant area one,and the pressure recovery performance of the former is better than that of the latter.For the ejectors tested in this paper,the stagnation pressure ratios of the second-throat supersonic-supersonic ejector at the limiting condition are approximately 10% lower than those of the constant area one when the contraction angle of the mixing chamber is 4°,and the maximum compression ratio is 12%-30% higher.When the contraction angle of the mixing chamber is 6°,the pressure matching performance of the second-throat supersonic-supersonic ejector declines sharply,and the pressure recovery performance remains almost the same.When the contraction angle of the mixing chamber is 8°,the supersonic-supersonic ejection phenomenon does not take place any longer.
文摘The effect of the secondary flow on the starting pressure of a second-throat supersonic ejector has been investigated by adapting the height of the secondary flow inlet.The obtained results show that an optimum value of the secondary inlet height exists,and the starting pressure of the ejector becomes a minimum at that condition.Based on the results of the pressure measurements,a qualitative analysis has been made to clarify the flow behavior and the physical meaning of the performance diagram.It appears that the choking phenomenon of the secondary flow plays an important role in the starting process of the ejector.When the secondary inlet height is relatively small,the choked secondary flow and the supersonic primary flow could be employed to protect the static pressure in the suction chamber from being disturbed by the back pressure effect at a certain primary stagnation pressure,which is lower than the starting pressure for the case of the zero-secondary flow.However,as the secondary inlet height increases and exceeds a critical value,the static pressure in the suction chamber rapidly increases,and the starting pressure of the ejector increases accordingly.
