Study on Trapped Oil and Cavitation of Jet Fuel Gear Pump

In order to explore the causes of trapped oil and cavitation formation during the operation of aviation fuel gear pump to ensure the safe and reliable operation of the pump, dynamic grid technology and Realizable were adopted. The k-ε turbulence model and Schnerr-Sauer cavitation model were used to simulate the three-dimensional transient state of the jet fuel gear pump. The results show that: 1) the air bubbles are mainly distributed in the tooth cavity of the inlet end of the gear pump due to the low inlet pressure and the vortex. 2) Under the effect of high pressure and bubbles at the outlet, an approximately closed tooth cavity is formed near the outlet end, and the trapped oil pressure is generated, whose pressure value is 16 times that of the inlet pressure. 3) As the outlet pressure decreases, the trapped oil pressure in the tooth cavity decreases, but the area of the low pressure area increases, and the cavitation area shows a diffusion trend. 4) The high pressure value formed in the tooth cavity is mainly affected by the speed of the gear. As the speed decreases, the high pressure value gradually decreases to the outlet pressure, and the pressure value decreases slowly with the change of the rotation Angle; The speed decreases, cavitation weakens and the cavitation bubbles formed in the tooth cavity gradually shrink to the oil film between teeth.