Diesel Electro-injector:A Numerical Simulation Code

A simulation code of an electro-injector for Diesel engines is presented with the preliminary parametric analysis carried out with the code. The simulation code is based upon the concentrated volume method as for the chambers of the system. Energy and flowrate conservation equations and dynamic equations are used for the movable parts of the system under stress or friction. The magnetic force acting on the electro-injector actuator has been calculated by means of a Finite Element simulation. The one-dimentional code simulated the propagation in feeding pipes and the control of the electro-injector. The program, infact, uses the method of the characteristic equations to solve conservation equations, simulating the propagation in a pipe between two chambers.

The sensitivity analysis has pointed out that the parameters which are influenced by the propagation in the pipes are: needle lift, injected flow-rate, pressure in each chamber and volume. The perturbations reduce the effective pressure of injection and are influenced by pipe lenghts and diameters.