Modelling of Gasoline and Ethanol Hollow-Cone Sprays Using OpenFOAM
Paper i proceeding, 2011
Over the past few years, an open-source code called
OpenFOAM has been becoming a promising CFD tool
for multi-dimensional numerical simulations of internal
combustion engines. The primary goal of the present
study is to assess the feasibility of the code for
computations of hollow-cone sprays discharged by an
outward-opening pintle-type injector by simulating the
experiments performed recently by Hemdal et al.
(SAE 2009-01-1496) with gasoline and ethanol
sprays under the following conditions: air temperature
Tair=295 or 350 K, air pressure pair=6 bar, fuel
temperature Tfuel=243, or 295, or 320 K, and fuel
injection pressure pinj=50, or 125, or 200 bar. To
simulate the experiments, a pintle injector model and
the physical properties of gasoline were implemented
in OpenFOAM. The flow field calculated using the
pintle injector model is more realistic than that yielded
by the default unit injector model normally used in
OpenFOAM. Moreover, a number of modifications
were made to the standard implementation of several
spray models in OpenFOAM, with modifications in the
implementation of the KHRT model having noticeable
effects on the accuracy of the simulated liquid
penetration and Sauter mean diameter (SMD).
Results of numerous simulations performed by
running OpenFOAM and activating various spray
models indicate that (i) a combination of the
Rosin-Rammler distribution with Reitz-Diwakar
secondary breakup model and (ii) the KHRT model
yield the best agreement between the measured and
computed spray penetration length, with the latter
model showing the best performance as far as the
SMD obtained from high-pressure (200 bar) sprays is
concerned.