DEVELOPMENT OF A FAST AND SIMPLE SIMULATION-MODEL FOR THE FUEL-INJECTION SYSTEM OF DIESEL-ENGINES

The fuel injection system is one of the most important parameters for the operation of diesel engines. It controls the combustion mechanism in the engine cylinder and the mechanisms that lead to the formation o f pollutants. A great deal of effort has been made up to now to simula te the operation of the fuel injection system, using complicated simul ation models. These models require a great deal of computational time and the knowledge of precise engine geometrical data that usually are unknown. In the present work a new and simple algorithm is proposed fo r the simulation of fuel injection systems that is very fast, requirin g little computational time and the least possible geometrical data. T he proposed model aims to overcome the difficulties during field appli cations where it is impossible to know details of the geometry of the system and especially about the delivery valve and the injector. The a lgorithm is written in FORTRAN-77 language and provides the fuel injec tion rate and the conditions at the nozzle exit with reasonable accura cy. The method is applied to a high speed direct injection diesel engi ne and the results are compared with experimental data. Furthermore, i n order to validate the proposed model against other detailed models, a comparison is given between the present model and a detailed simulat ion model developed by the present research group. From this compariso n, a good accuracy of the model is revealed when compared against expe rimental data and the predictions of the previous detailed model, desp ite its simplicity. (C) 1998 Elsevier Science Ltd.