Large-Eddy Simulation of a Reacting Spray Flame Using Flamelet Approach
Armin Wehfritz, Ossi Kaario, Heikki Kahila, Mahdi Ghaderi-Masouleh, and Ville Vuorinen*
Aalto University, School of Engineering
Department of Mechanical Engineering
*ville.vuorinen@aalto.fi
In the present research we present results related to CFD modeling of the “Spray A” target spray as
defined by the Engine Combustion Network. Spray A is a diesel-like n-dodecane spray which
consists of a diffusion flame enveloping the spray, and a flame in the premixed regime in the fuelrich core of the spray. We model the spray A using the large-eddy simulation (LES) and flamelet
generated manifold (FGM) approaches by implementing a new flow solver in the OpenFOAM,
opensource CFD C++ library. Our results indicate good agreement between the experimental data
and the present simulations for the flame lift-off length and ignition delay times. However,
sensitivity of the chemical mechanism is clearly pointed out as well. We analyze the structure of the
spray in-depth, and indicate the presence of a “cool flame” characterized by a pool of formaldehyde
in the core of the spray. Last we point out the characteristic structures of the spray A by analyzing
the energy containing modes of the combusting spray jet.