Based on hydromachanics and the law of conservation of energy by means of the Bernoulli Equation, the matching relation of a pump pressure and delivery, losing energy of the magma when it flows along the pipes are res...Based on hydromachanics and the law of conservation of energy by means of the Bernoulli Equation, the matching relation of a pump pressure and delivery, losing energy of the magma when it flows along the pipes are researched. This thesis provide the theoretical basis for equipment selection and selection of pipeline.展开更多
The 2-meter High-speed Free-jet Wind Tunnel(2 m HFWT)is China’s first large-scale open-jet trisonic wind tunnel.Compared to traditional closed high-speed wind tunnels,this wind tunnel is endowed with remarkable advan...The 2-meter High-speed Free-jet Wind Tunnel(2 m HFWT)is China’s first large-scale open-jet trisonic wind tunnel.Compared to traditional closed high-speed wind tunnels,this wind tunnel is endowed with remarkable advantages of ample test chamber space,less interference from the tunnel wall,flexible model support mode,and adjustable continuous variation of the Mach number.Nevertheless,its unique structure makes traditional wind tunnel control methods difficult to apply and brings significant challenges to wind tunnel flow field control.In this paper,a flow field control system is designed for the 2 m HFWT by comprehensively using advanced control technologies such as neural network,gain scheduling,feedforward control,and adaptive control.Through practical application tests,it is proved that the proposed control system successfully solves the problem of high-precision flow field control under continual depletion of storage tank pressure,and realizes distinctive functions of adaptive static pressure matching and continuously varying Mach number at supersonic speed.In addition,due to the application of workflow technology,the flow field control system can flexibly adapt to the implementation of tests of different types and operation conditions,thus fully satisfying the needs of conducting various conventional and special tests in the 2 m HFWT.展开更多
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
文摘Based on hydromachanics and the law of conservation of energy by means of the Bernoulli Equation, the matching relation of a pump pressure and delivery, losing energy of the magma when it flows along the pipes are researched. This thesis provide the theoretical basis for equipment selection and selection of pipeline.
文摘The 2-meter High-speed Free-jet Wind Tunnel(2 m HFWT)is China’s first large-scale open-jet trisonic wind tunnel.Compared to traditional closed high-speed wind tunnels,this wind tunnel is endowed with remarkable advantages of ample test chamber space,less interference from the tunnel wall,flexible model support mode,and adjustable continuous variation of the Mach number.Nevertheless,its unique structure makes traditional wind tunnel control methods difficult to apply and brings significant challenges to wind tunnel flow field control.In this paper,a flow field control system is designed for the 2 m HFWT by comprehensively using advanced control technologies such as neural network,gain scheduling,feedforward control,and adaptive control.Through practical application tests,it is proved that the proposed control system successfully solves the problem of high-precision flow field control under continual depletion of storage tank pressure,and realizes distinctive functions of adaptive static pressure matching and continuously varying Mach number at supersonic speed.In addition,due to the application of workflow technology,the flow field control system can flexibly adapt to the implementation of tests of different types and operation conditions,thus fully satisfying the needs of conducting various conventional and special tests in the 2 m HFWT.
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.
