A posteriori assessment of consumption speed correction for LES with tabulated methods

TL;DR

This paper evaluates a consumption speed correction model in LES of premixed combustion, demonstrating its effectiveness in aligning coarse mesh simulations with refined mesh results, and proposes an extended model for partially-premixed flames.

Contribution

It introduces a posteriori assessment of a consumption speed correction model and proposes an extended model for partially-premixed combustion in LES.

Findings

Correction restores flame length and width in coarse mesh simulations.

Model performs well in self-driven oscillation conditions.

Extended model shows promise in high-pressure combustor applications.

Abstract

Large eddy simulation of propane/air jet flame in the wrinkled flamelets regime of the Borghi diagram is used to assess the performance of a recently developed consumption speed correction model in premixed combustion. The combustion is modelled using flamelet tabulation with a presumed probability density function. The investigated flame does not lie in the shear layer and is subjected to self-driven oscillations, which is ideal to test the model performance. The flame behaviour is first discussed using an accurate simulation performed on a refined mesh requiring no correction. The same modelling framework used on a coarser mesh is observed to overestimate the consumption speed, leading to a shorter flame. The application of the consumption speed correction leads to the recovery of the flame length and width observed for the refined mesh, demonstrating its effectiveness. An extended model for partially-premixed combustion is also proposed and preliminarily tested on a high-pressure combustor.