Large eddy simulation of turbulent diffusion jet flames based on novel modifications of flamelet generated manifolds

摘要

A novel mathematical definition is introduced to achieve the inherently monotonic progress, namely Absolute Cumulative Variation (ACV). The classical progress variable is defined as a weighted summation of species mass fraction while weight factors are determined in the ad-hoc procedure. The ACV definition presents the systematic method to generate a fully bijective look-up table appropriate for the vast combustion applications. This method utilizing the preferential diffusion effects and has the potential to predict the autoignition delay time as well as pollutants, like Y-CO and Y-NO. The flamelet-generated manifold is coupled with ACV to make the ACV-FGM method. Furthermore, the Variable Ignition Mixing Layer (VIML) is presented as a modified method to generate a 2-D look-up table for the multi-inflow streams as well as varying composition reactants at the domain boundaries. This model helps to reduce the size of the look-up table for complex inflow boundary conditions and computational cost as well. The validation process for the ACV-FGM and VIML methods includes a one-dimensional laminar flame along with large eddy simulation (LES) of the Sandia piloted flames D, E, and F, and Delft Jet-Hot Coflow (DJHC) burner as lifted turbulent jet flame. The results indicate the ACV-FGM method successfully predicts the autoignition delay time, lift-off height, temperature rise as well as spices mass fractions and pollutants. Moreover, The VIML method appropriately reproduces the variation of chemical compositions and temperature at the domain boundary using the 2-D look-up table. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.