A Study of Fuel Injection Systems in Diesel Engines 760551
In this study, the authors show their analytical model of the fuel injection system in a diesel engine, which is constructed to be as accurate but as simple as possible and to have good application in the development of new fuel injection systems.
In the first part, the authors initially describe the model assumptions, classification of injection phenomena, and fundamental equations considering the compressibility, inertia and viscocity of hydraulics and the movements of valves and other components to improve the accuracy of the systems.
Secondly, regarding the experimental constants and physical properties of the fuel, the authors show the method of selection they used to simplify the analytical model and to get good agreement as a result but without losing physical meanings. Correlations between calculated and experimental results are shown for some areas which have not been carefully investigated before, as follows: (1) sonic velocity in the fuel (2) pressure loss at pipe connections (3) effective area of nozzle hole (4) correction factor of valve area (5) damping factor of valve motion (6) coefficient of restitution of valve at valve seat.