Investigation of flow structures in hydrogen-enriched premixed combustion

Abstract

Large Eddy Simulation (LES) coupled with Thickened Flame (TF) model has been used to investigate the flow structures in hydrogen-enriched premixed combustion. An unconfined strongly swirled flow, operated at atmospheric condition, is investigated for varying hydrogen percentage as well as swirl strength. Turbulence-chemistry interaction is coupled through LES-TF approach where 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. The results show that higher combustibility of hydrogen increases the reaction along the flame front, raises temperature in the reaction zone and thus leads to combustion induced vortex breakdown. In particular, primary interest lies on understanding the flow physics due to hydrogen addition.