An Experimental and Computational Study of a Swirl-Stabilized Premixed Flame

TL;DR

This study combines experimental PIV measurements and LES simulations with a Thickened Flame model to analyze a swirl-stabilized premixed flame, revealing detailed flow dynamics, heat release patterns, and vortex behavior.

Contribution

It provides a comprehensive comparison between experimental data and LES predictions using a Thickened Flame model for a swirl-stabilized premixed flame.

Findings

Good agreement between LES and experimental data.

Double-peak RMS fluctuation profile observed.

Precessing vortex core is identified and characterized.

Abstract

An unconfined strongly swirled flow is investigated for different Reynolds numbers using particle image velocimetry (PIV) and Large Eddy Simulation (LES) with a Thickened Flame (TF) model. Both reacting and non-reacting flow results are presented. In the LES-TF approach, the flame front is resolved on the computational grid through artificial thickening and the individual species transport equations are directly solved with the reaction rates specified using Arrhenius chemistry. Good agreement is found when comparing predictions with the experimental data. Also the predicted RMS fluctuations exhibit a double-peak profile with one peak in the burnt and the other in the un-burnt region. The measured and predicted heat release distributions are in qualitative agreement with each other and exhibit the highest values along the inner edge of the shear layer. The precessing vortex core (PVC) is clearly observed in both the non-reacting and reacting cases. However, it appears more axially-elongated for the reacting cases and the oscillations in the PVC are damped with reactions.