Transient Simulation And Optimum Analysis Of Regulating Valve Flow Field In Liquid Rocket Engine

The flow field inside thrust chamber regulating valve and preburner regulating valve of a hydrogen oxygen rocket engine has been investigated using a computational fluid dynamic approach.Trust control of rocket engine is a key technology and an important development direction in the field of aerospace.Regulating valve is the actuator of thrust control in liquid rocket engine.The performance of valve directly determines the accuracy of regulation.Dynamic computational simulations of valve response to varying flow conditions can yield great significance.Based on the calculation and physical models of FLUENT software,the static and dynamic simulation of the two regulating valves was carried out by using dynamic mesh and UDF(user-define function).By using the static simulation results under different working conditions,We analyzed the pressure characteristics and velocity characteristics of flow field inside the two regulating valves,and discussed the variation law of working parameters such as discharge coefficient.According to the principle and design requirements of the two regulating valves,we simulated the opening process of the thrust chamber valve and the feedback regulating process of the preburner valve.After analyzing the static and dynamic simulation results,we changed the structural parameters of the two regulating valves and then compared the flow field characteristics and put forward optimum design ideal.The simulation result shows that: Two valves conform the requirements and can regulate and stabilize flowrate.The thrust chamber regulating valve has a high flow stability.In the opening process,the transient pressure between inlet and outlet is affected by the velocity and flow variable rate of the rack sleeve.Reducing the number of throttle windows can improve the flow field symmetry and reduce the flow coefficient.The flow in the preburner valve is unstable.The flow coefficient of the two throttle windows varies greatly.The feedback control element can timely response to different pressure disturbances,and it can stabilize flowrate.Regulating response time and flowrate stabilization effect can be optimized by changing damping parameters,and friction has the most significant effect in the regulating process.