Numerical Simulation Of The Physical Process Of Exhaust Gas And Water Injection Mixed Cooling

The torpedo combustion chamber is a key component of torpedo thermal power system.The propellant is mature products and its optimized combination used in thermal power torpedo for the past decades,such as OTTO-II and HAP,kerosene,and so on.Most of the propellant exhaust gas' temperature could reach about 2500 K,some even up to 3000 K.Because of the limitations of turbine materials,such high temperature gas couldn't be used to promote turbine work.Therefore,the need for high temperature gas water injection cooling,the cooled low temperature gas can be used to drive the turbine to do work.It is necessary to study how to reduce the temperature of the high temperature gas.In this dissertation,the computational fluid dynamics software Fluent is used to simulate the physical process of the mixed cooling of high temperature gas and water injection by using the component transport model and DPM discrete model.First of all,In order to verify the correctness of the method and model,the combustion products of kerosene and nitric acid and water injection mixed cooling process was calculated by numerical simulation.the correctness of the proposed numerical method and model is verified by comparing the calculated results of the mixed gas temperature and the theoretical calculation.Secondly,choosing kerosene and liquid oxygen as fuel and obtaining the combustion products by thermodynamic calculation.The numerical simulation of the two-dimensional of the physical process of high temperature gas and water injection mixed cooling was carried out.By changing the water injection rate and average liquid drop size,its influence of exhaust gas and water injection cooling process was analyzed.The Research found that in a certain range,increasing the water injection rate can improve the cooling effect;in a certain range,the little change of average liquid drop size has little effect on the mixed cooling effect.Finally,the numerical simulation of the three-dimensional of the high temperature gas and water injection mixed cooling's physical process was carried out.By changing the upstream injection pressure,the injection angle of the cooling water and the cone angle of the spray,we researched the effect of these factors on the mixed cooling effect.By study we found that in a certain range,improving the quality of droplet atomization by increasing the upstream injection pressure could improve the effect of exhaust gas and water injection mixing cooling,but not the higher the upstream injection pressure the better the cooling effect;Compared with the cooling water in the vertical direction of the wall sprayed into the combustion chamber,the cooling water was sprayed into the combustion chamber at the right angle to improve the effect of exhaust gas and water injection mixed cooling,if the angle is too step to improve the effect of mixed cooling;In a certain range,by increasing the cone angle of the spray,also can improve the exhaust gas and water injection mixing cooling's effect.In a certain range,by increasing the number of nozzles,the effect of exhaust gas and water injection mixing can be improved to a certain extent.