Fuel Injection Process Computations Using the Eulerian Multidimensional Model 2005-01-1243
Diesel fuel injection process calculations have been performed by means of in-house developed mathematical models. An Eulerian multidimensional code for in-cylinder two-phase flow computations is used in conjunction with a hydrodynamic one-dimensional model of a fuel injection system. The multidimensional model comprehends all basic processes, which play a role in spray formation. The compressible gaseous flow with transport of species is solved together with the flow of dispersed liquid phase using the Eulerian reference frame for both phases. The two-way coupling between the phases in mass, momentum, and energy balances is considered. A detailed description of liquid phase is present, taking into account drop size distribution in terms of the multi-continua approach. The hydrodynamic model capable of simulating common fuel injection systems is used for the rate-of-injection computations to provide realistic boundary conditions to the spray model. The results of computations of fuel spray evolution are presented for an engine of simplified geometry equipped with the Common-Rail injection system. Different rate-of-injection shapes are computed, with single and multiple injection events, and their influence on fuel spray formation is shown. The combination of 3-D and Q-D models is outlined, which provides possibilities to enhance the spray model by simplified diesel combustion simulation and to calibrate model closure parameters.