On the Modelling of Explosion Deflagrating Flames

AbstractThis paper presents results from numerical calculations using the large eddy simulation (LES) technique of deflagrating flames inside a laboratory scale explosion chamber. The LES technique has been proved to be an extremely powerful and highly reliable modelling tool for turbulent reacting Flows. Two reaction rate models are used to examine the flame structure and speed, and the generation of overpressure inside the combustion chamber. Both models are formulated ba ed on modified formulations of the flame surface density (FSD). The test case used for model validation is an open-end rectangular combustion chamber with three baffles plates and one solid square obstacle as presented in this paper. A stoichiometric propane/air air mixture is used here for all calculations, and model validation is carried out against experimental measurements. Results are presented in the paper for the generated over pressure, reaction rate and the flame structure, location, speed and acceleration. It was concluded that careful selection of the model parameter is needed in order to predict the correct flame structure and speed. Details of the two models used together with results are presented and discussed in terms of different flame parameters