Fuel Leakage of Plunger Pair under Two Postures

ZHANG Yong; LI Pan; GAO Zhenbo; WANG Dandan

Vehicle Engine ›› 2022, Vol. 0 ›› Issue (4) : 49-56.

ZHANG Yong,LI Pan,GAO Zhenbo,WANG Dandan

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Abstract

The plunger posture may be eccentric and inclined when high-pressure common rail injector is running. In order to study the fuel leakage of plunger pair comprehensively, the mathematical models including Reynolds equation, film thickness equation, cross-section velocity equation, non-isothermal flow equation, steadystate heat conduction equation, and parametric equation of fuel physical property were established. The numerical analysis was conducted based on the finite difference method. The fuel leakage rate was calculated by using the mathematical model and compared with that calculated by the classical formula and the test value, which verified the validity of the model. The trends of leakage rate, film thickness, temperature, density, viscosity and specific heat capacity for gap fuel were acquired in the inclined and eccentric state of plunger sleeve.