Study Of The High Temperature Gas-Liquid Two Phase Flow Rate Proportional Conrtol Valve

Fuel supply control is the key technique for the working performance of the scramjet engine. It plays an important role in the improving of the engine's performance and efficiency. Because scramjet use the endothermal carbon hydrogen fuel as the refrigerant, when the temperature becomes high, the fuel will be at the two phase flow state, which will change the density and the viscosity of the fuel, and this result in more difficulty to design of fuel control. The density of the fuel changes so great that the control of the mass flow rate becomes very difficult. Therefore, it is very necessary to make scientific researches on two phase flow to control fuel flow rate better. Because of the different thermal expansion of the flow rate control valve made of ordinary materials in high temperature condition, there will be larger leakage or friction force between the valve body and the spool .To solve these problems, the proportional flow rate valve is made of GH783 alloy.The thesis analyzes the high temperature gas-liquid two phase flow rate proportional control valve. A two phase flow model is built using finite element software-Fluent. The relationship of two phase flow rate, pressure and spool displacement is analyzed, and flow coefficient of valve port is modified. Based on force analysis, the static and dynamic mathematical models of the valve are built, some parameters of which are modified according to Fluent simulation results. The proportional characteristics, flow rate-pressure drop characteristics and step response of the valve are simulated using Matlab/Simulink. The proportional characteristic curve, flow rate-pressure drop characteristic curve and step response characteristic curve are obtained at the room and high temperature under different working conditions. Then the results are compared. A test rig is set up and the experiment on the valve is carried out at the room temperature and high temperature. The experimental proportional characteristics are obtained and compared with the simulation results.