Adjustment and Verification of Model Parameters for Diesel Injection CFD Simulation

In co-operation between a diesel engine manufacturer (DEUTZ), a CFD software supplier (FLUENT) and two universities (FH Aalen and RWTH Aachen), the practicability of industrial CFD simulation for the Diesel injection process has been investigated. Since these simulations still rely on several empirical parameters, the main aim of this investigation was to obtain an adjusted set of model parameters in order to achieve realistic results with the current FLUENT version.

To verify the simulations, droplet diameters and velocity distributions of the spray have been measured by Phase Doppler Anemometry (PDA) in a model chamber.

A Lagrangian Discrete Phase Model has been used for spray simulation. Different primary break-up models and two secondary spray break-up mechanisms, the Kelvin-Helmholtz theory and Rayleigh-Taylor instabilities have been investigated. Furthermore, droplet evaporation, droplet collision and the influence of droplet shape on drag have been accounted for.