Numerical Simulation Of Jet Atomization Of Water Ramjet Engine

The water ramjet engine has a high specific impulse,excellent power performance,applicability to the underwater environment,and is a good form of power.In the water ramjet engine,the water needs to be atomized through the nozzle and enter the combustion chamber,and the atomization performance of the nozzle directly affects the reaction process,thereby determining the performance of the engine.Therefore,the study of nozzle atomization process is of great significance in engineering practice.In this paper,the VTD combining the two-phase flow model of VOF and DPM is used by numerical simulation method,combined with grid adaptive technology,to conduct a cross-scale study of the atomization process of centrifugal nozzle jet under the background of water ramjet engine.Firstly,the model is established according to the reference literature for simulation,and the accuracy of the model is verified while the mesh independence is verified.The atomization process of centrifugal nozzle is simulated,the principle of VTD is introduced,and the specific process of jet atomization is analyzed.A single-nozzle model was established for jet atomization,and the atomization morphology was analyzed,the pressure difference,velocity direction and medium were changed,and the influence of different boundary conditions on the atomization process was explored.The double-nozzle-to-jet model was established,and the interference between nozzle jets was explored,and the boundary conditions such as distance between nozzles,nozzle diameter,pressure difference and other boundary conditions were changed,and the influence of different boundary conditions on the jet atomization process under the condition of double-nozzle-to-jet interference was explored.It is concluded that the VTD method can effectively and truthfully reflect the atomization process such as primary crushing and secondary crushing,and is suitable for the study of centrifugal nozzle jet atomization process.In the process of single nozzle jet atomization,the role of pressure difference is mainly reflected in the outlet speed and secondary crushing area,the speed direction has an impact on the overall process of the centrifugal nozzle,the same boundary conditions have different atomization effects for different media,and it is necessary to adjust the boundary adjustment according to the medium to achieve the optimal atomization effect;The increase of the distance between nozzles will reduce the particle group density and the mass concentration at the intersection,increase the diameter of the high-concentration ring area at the intersection,and increase the nozzle diameter will cause the concentration of the discrete phase particle group in the outflow field to decrease,the particle size will increase,the mass concentration at the junction will increase,and the time required to reach the stable state will decrease with the increase of pressure difference.