Doubly Conditional Source-term Estimation (DCSE) applied to a series of lifted turbulent jet flames in cold air

作者：Dovizio Daniele; Labahn Jeffrey W; Devaud Cecile B^*

来源：Combustion and Flame, 2015, 162(5): 1976-1986.

DOI：10.1016/j.combustflame.2014.12.016

• Doubly Conditional Source-term Estimation
• RAM
• Lifted turbulent flame
• Lift-off height
• Combustion

The objective of the present study is to evaluate the applicability of a new partially premixed combustion model, Doubly Conditional Source-term Estimation (DCSE), applied to a series of lifted jet flames using Reynolds Averaged Navier Stokes (RANS) calculations. The partially premixed implementation involves double conditioning on two variables, mixture fraction and progress variable. The present work represents the first application of DCSE for lifted turbulent flames. Conditionally averaged chemical source terms are closed by conditional averaged scalars which are obtained by inverting an integral equation. Three different jet conditions are simulated, over a range of Reynolds number between 7,000 and 19.500. Two-equation k-epsilon turbulence model is used to solve the flow field. The predicted mean centerline and radial profiles of methane concentration are in good agreement with the experimental values. The present DCSE calculations are successful in predicting the lift-off heights and reproducing many aspects of the flame structure in agreement with the experimental observations. The stabilization point is located on the fuel lean side, the mixture fraction isolines are deflected around the flame base, significant entrainment of air by the fuel jet upstream of the flame stabilization point is observed and the calculated flame width becomes larger with increasing Reynolds number. Some discussion is given related to triple flames. Future work is suggested related to the scalar dissipation rate modelling and DCSE implementation in Large Eddy Simulation (LES).

• 出版日期2015-5