Numerical Simulation Of Internal Flow Field In Aluminium-based Water Ramje Engine

As one of the underwater propulsion systems,aluminium-based water ramje engine has a good application prospect and the research on which is important.In order to study the engine and improve the work performance of the engine,the paper used fluent to simulate the internal flow field in the aluminum-based metal-fuel engine.In order to study the energy characteristics of the aluminum-based metal-fuel,it was calculated by thermal calculation,the results showed that,the energy density of aluminum-based metal-fuel was larger than others,the propellant had great energy characteristics with the increase of aluminum content and the specific impulse can reach 5000m/s.The internal ballistic test engine was caculated through the numerical calculation,which is consistent with the result on the other paper,the correctness of the numerical simulation method was confirmed.The numerical simulation of the aluminium-based water ramje engine was carried out,compared with the the results of thermodynamic calculation,the relative error was less than 5%,the distribution of internal flow field was reflected well and it is important to the design of water ramjet.In the last,the optimized design of the water ramjet was carried out,for the optimal performance,the influence of different conditions on the internal flow field of the engine was calculated by changing the first water inlet position,the second water inlet position,the water ratio and the diameter of water droplets.It concluded that the reaction of aluminum and water would be affected with the distance of the first water inlet position changing,when the distance is small,the reaction of aluminum and water zone was closed to the burning surface,which leaded to the temperature decreaseing near the burning surface,it was bad for the reaction of propellant or aluminum,with the distance increasing of the first water inlet position or the distance decreasing of the second water inlet position,the temperature was reduced because of the inlet of the water droplets,which destroyed the reaction of aluminum and water.when the the distance of the second water inlet position is large,the water droplets failed to evaporate completely,the work efficiency of engine was reduced.As the main gas phase working medium,water vapor was important for the engine,when the water ratio was small,the specific impulse was small too,the specific impulse increased with the increasing of water ratio,but when the water fuel ratio was big enough,water droplets could not evaporate completely,the work efficiency of engine was reduced and the specific impulse was not increased even decreased.The diameter of water droplets also had a great influence on the engine,especially for the evaporation of the water droplets,the water droplet diameter must be within a reasonable range.In order to achieve the best performance of engine,the above parameters need to be properly designed.