Numerical Study Of Exhausted Gas Plume From Solid Rocket Motor Cooled By Water Spray

With the rapid development of Chinese national defense industry,solid rocket engines are widely used in weapons and equipment.During the rocket launching process,the high-temperature and high-pressure gas plumes ejected from the engine nozzles undergo secondary combustion during the diffusion process,and the impact launch platform.Energy conversion occurs,the platform temperature reaches 2500 K or more,and it has serious ablation effect on ground equipment such as launching platforms.In order to reduce the ablation of the gas plume to the launching platform,it is necessary to cool the solid rocket engine launching platform by means of a water injection spray.In this paper,based on the launch of launch vehicle,the interaction process and cooling effect of liquid water and gas jet are studied by using commercial software F numerical simulation to establish a reference model for the efficient design of water injection cooling system.The work includes the following aspects:(1)Based on the component transport model,the free jet is simulated to obtain the three-dimensional distribution result of the gas plume,and the numerical simulation results are compared with the existing experimental results to verify the applicability and accuracy of the numerical simulation model..The existence of secondary combustion is considered in the free jet flow.The numerical simulation results can be used to obtain the following conclusions: The numerical simulation can accurately simulate the free jet flow.The secondary combustion of the gas mainly occurs outside the middle plume and the impact platform.On the surface,the temperature in the area where the secondary combustion occurs will increase by about 200 K to 300 K.(2)Establish a water injection model based on the DPM model,simulate the gas flow field of the gas plume,compare the numerical simulation results of the water injection flow field with the existing experimental results,and verify the applicability and accuracy of the water injection model.The simulation of the influence of secondary combustion of gas on the flow field under water injection conditions can be found through numerical simulation results: the water injection spray seriously damages the structure of the lower half of the gas flow field,and the gas flow temperature drops rapidly,and the gas is injected into the gas.After the temperature is lowered,the secondary combustion phenomenon of the gas can be greatly suppressed.(3)By changing the spray intensity,the fog cone angle,the water mist particle size,the upstream pressure of the nozzle,the initial temperature of the water spray,the nozzle position,the nozzle installation angle,the uniformity of the nozzle injection,etc.For comparison,the effects of relevant nozzle working factors and nozzle position factors on the cooling effect of the gas flow field were studied.The simulation results show that the spray cooling can greatly reduce the impact platform temperature.Within a certain range,the spray intensity,nozzle upstream pressure,fog cone angle and nozzle distance from the impact platform should be increased as much as possible to reduce the nozzle installation angle and the average particle size of the water mist.The above measures can change the relevant injection factors to increase the gas.The evaporation of water in the core area of the plume will achieve a better cooling effect;when the above related injection factors exceed the corresponding range,the cooling effect of the flow field will not change significantly.