Numerical Study on Cavitation Flow Characteristics in Diesel Fuel Injector Control Valve

The flow and cavitation in the flow passage of the control valve are calculated, and the effects of operating conditions (including injection pulse width, rail pressure and ball valve lift) on the flow and cavitation characteristics are analyzed under dynamic boundary conditions. The simulation results show that the cavitation in the outflowing control-orifice (OA) and the guide-hole are almost unaffected by these operating conditions. In contrast, the cavitation process in the ball valve chamber has two distinct stages, which can be classified as violent and relatively smooth. The shorter the pulse width, the more severe the average degree of cavitation in the ball valve chamber; however, the risk of cavitation erosion on the ball valve and the ball valve seat surface does not increase too much. The increase of rail pressure and the increase of ball valve lift will aggravate the cavitation, and the cavitation position will move forward closer to the sealing annular surface.