Direct Numerical Simulation Analysis of The G-Equation in Premixed Combustion
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This study is aimed at the development of a method applicable to the description of turbulent premixed flames in large eddy simulation framework. The basic idea is to use a transport equation to describe the propagation of the flame contour and thus avoid the calculation of the inner flame structure on the LES coarse grid. The so called G-equation is used for that purpose. One isolevel of the G variable G = G o defines the flame location. While this idea has received considerable attention, it has been mainly used in constant density (“thermodiffusive”) simulations. Extension to variable density flows of the kind encountered in combustion introduces serious difficulties. A novel method: the Forward Estimation of Temperature (FET) is devised in this investigation to deal with these problems. Flame/vortex and flame/turbulence interactions are calculated using the new model and compared with direct numerical simulations relying on simple chemistry representation of the reaction rate. Results obtained with the G-FET method are satisfying and this technique is now ready to be tested in a real LES reactive calculation.
KeywordsLarge Eddy Simulation Direct Numerical Simulation Heat Release Rate Flame Front Flame Propagation
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