空化对分流叶片式航空燃油泵性能的影响研究

Research on the Effect of Cavitation on the Performance of a Split-Vane Aviation Fuel Pump

为探究空化对某分流叶片式航空燃油泵性能的影响规律,本文基于RNG k-ε湍流模型与Zwart-Gerber-Belamri空化模型,利用ANSYS CFX软件对其内部流场进行了数值模拟,分析不同流量和不同空化程度下燃油泵内流动特性及压力脉动规律。结果表明:在不同流量下,空泡的演变规律相同,均随空化余量的降低,先从长叶片吸力面开始,逐步发展到短叶片吸力面,最后出现在短叶片压力面;小流量时泵的空化性能最优,同时,随着流量的逐渐增加,初生空化和临界空化逐渐出现;长短叶片压力面压力载荷在相对位置0.7~0.9处均存在波动,空化余量越小,波动越明显,且相比于长叶片,短叶片在此处压力载荷波动幅值更大,说明空化对短叶片做功的影响更大;空化对长短叶片前端压力脉动均有影响,但是对短叶片的影响略小。

In order to explore the effect of cavitation on the performance of a split-vane aviation fuel pump, based on the RNG k-ε turbulence model and the Zwart-Gerber-Belamri cavitation model, this paper numerically simulates its internal flow field using ANSYS CFX software.The internal flow characteristics and pressure pulsation law of the fuel pump are analyzed under different flow rates and different cavitation levels.The results show that under different flow conditions, the evolution law of cavitation is the same, and with the decrease of the cavitation margin, it starts from the suction surface of the long blade, gradually develops to the suction surface of the short blade, and finally appears on the pressure surface of the short blade.In addition, it is found that the pump’s cavitation performance is optimal under low flow conditions, and as the flow rate gradually increases, the earlier the primary cavitation and critical cavitation occur.In addition, it is found that the pressure load on the pressure surface of the long and short blades fluctuates at the relative position of 0.7-0.9.The smaller the cavitation margin, the more the fluctuation.Compared with the long blades, the amplitude of the pressure load fluctuations of the short blades is clearly greater.It shows that cavitation has a greater influence on the work of short blades.Meanwhile, the pressure pulsation on the front tip of both long and short blade is influenced by aviation, but the effect on the short blade is slightly smaller.