热态壁面条件下的液膜冷却实验与仿真

To understand the impact of jet flow rate and jet angle on liquid film spreading shape, wall temperature, and liquid film thickness, an independent liquid film cooling experiment system based on the heated -wall conditions -was designed and constructed. The experiment focused on liquid film cooling with a jet angle of 25°-45° and a jet flow rate of 200-400 mL • min ' was conducted. The results show that increasing the jet angle leads to a decrease in spreading length, while spreading width and spreading angle increase. At a certain jet angle, liquid film spreading length, width and angle both increase with the growth of jet flow rate. Notably, when the jet angle is 25°, the jet flow rate increases from 300 m L • min ' to 400 mL • min ', the maximum increase in the liquid film spreading length is 20. 94 m m, and the increase in the jet flow rate can effectively reduce the wall temperature, when the jet angle is 35° and the jet flow rate is 300 mL • min ', the maximum wall temperature can be reduced by 141. 81 °C after cooling; The liquid film has a peak thickness at the impingement point on the wall, and the higher the liquid film flow rate, the higher the peak value. For instance, when the incidence angle is 25° and the flow rate is 400 m L • min ', the maximum peak value reaches 679. 32 jim. Additionally, a numerical model for liquid film cooling was established with the volume of fluid (V O F) method to calculate the evaporative heat absorption and flow spreading process of the liquid film. It is shown that when the jet flow rate is 300 m L • min ', the maximum deviation between the simulation results of liquid film thickness and the experimental results is 7. 9 %, which is within the 1 0 % error allowed for engineering applications, so as to verify the feasibility of the V O F method for the simulation of liquid film formation on jet impingement wall. T h e present research can provide significant reference for the liquid film cooling technology in liquid rocket engine.