液体火箭发动机涡轮泵管式扩压器 时序效应数值研究

To analyze the influence of clocking effect of pipe diffusers on the performance and pressure pulsation of high-speed turbopumps and elucidate the influencing mechanism, this paper conducts three-dimensional steady and unsteady numerical calculations of the entire flow field of a high-speedturbopump in a liquid rocket engine.The study investigates the influence of clocking effect of a pipe diffuser on the external characteristics of the turbopump, analyzes the energy loss inside the turbopump using the entropy production theory, and evaluates the level of pressure pulsation inside the turbopump using the root mean square (RMS) method.The results show that with an increase in the angle between the pipe diffuser blades and the volute tongue, the overall efficiency and head of the turbopump first increase and then decrease, with amplitudes of variations of 0.75% and 1.68 %, respectively. The turbopump exhibits better performance when the angle between the suction side exit of the pipe diffuser blades and the volute tongue is 20.5° and 25.5 °. The influencing mechanism is determined by the variation of vortices and energy losses near the exit of the expansion pipe below the volute tongue. The rotor-stator interference effect is the main cause of pressure pulsation inside the turbopump, and the clocking effect respectively has impacts of 37.7% and 67.6% on the pressure fluctuation at the turbopump outlet and near the volute tongue. The outlet region of the expansion pipe below the volute tongue exhibits the maximum value of pressure pulsation in the volute flow passage, and the influence of the clocking effect on the maximum value of pressure pulsation is 20.5 %. The findings of this study provide references for optimizing the performance and vibration of turbopumps in liquid rocket engines.