Investigations On Function Process Of Bubbly Water Ramjet Engine

The underwater gas-liquid two-phase jet propulsion is a new type of underwater propulsion method,which is put forward in order to meet the more strict requirements of the power system performance of the modern warship.Compared with the traditional propeller propulsion,the two-phase ramjet propulsor have many excellent properties,such as stronger anti cavitation ability,greater thrust,higher propulsion efficiency,simple structure,excellent mute performance and so on.In order to study the performance of the two-phase ramjet propulsor as comprehensive as possible,the numerical calculation and experimental study are used in this paper.In order to achieve numerical calculation,two-phase underwater ramjet propulsor can be separated into diffusre,mixing chamber and nozzle.For these three parts,the corresponding physical model is established in order to get the flow field parameters,such as flow velocity,pressure and so on.Through reasonable physical assumptions,the flow field parameters in diffusre and mixing chamber can be solved through algebraic equations;flow in the nozzle involves complex two-phase flow of gas and liquid,based on reasonable assumptions,the flow field parameters in nozzle can be solved through constant differential equation group.The results of numerical calculate show that the water speed at the inlet of the ramjet,the mass flow rate of Nitrogen,the pore size of the bubble generator and half contraction angle of nozzle have important influence on the thrust,specific impulse and propulsion efficiency of the ramjet.In the aspect of experimental study,the experimental model of the two-phase ramjet propulsor is designed and processed,water and gas supply pipeline system which is needed in the experiment is built,the pressure and thrust measurement system of the test bench is improved.Through the experiment,get the law of the engine performance which is influenced by water speed at the inlet of the ramjet,the mass flow rate of nitrogen,the pore size of the bubble generator and half contraction angle of nozzle.Finally,the numerical results are compared with the experimental results.Not only the reliability of the numerical results is verified,but also provide a theoretical basis and experimental foundation for further research of the underwater two-phase jet propulsion.In addition,the unique advantages of the two-phase ramjet propulsor compared with other underwater propulsion engines is clarified,this makes the practical application of the two-phase ramjet propulsor become possible.