The effect of pressure on the mixing field of reacting and non-reacting jet in crossflow.

Clean combustion demands good fuel-air mixing. Jet in crossflow (JICF) which has good mixing characteristics is a potential injection strategy for zero-carbon fuels, like hydrogen. The flow and mixing characteristics of JICF have been extensively studied for reacting and non-reacting flows at atmospheric conditions. However, the JICF characteristics at gas turbine relevant conditions remain unexplored. Hence, the objective here is to study the effect of pressure on the combustion and mixing characteristics in JICF configuration using LES. The analysis shows that jet penetration into the crossflow is impeded by early jet breakup, leading to increased mixing at high pressure (HP) conditions for a given momentum flux ratio. Under HP non-reacting conditions, the shear layer roll-up occurs at high frequency, enhancing the entrainment of air in the jet near field. However, in reacting conditions, the flame stabilization point plays a crucial role. At HP conditions, the flame stabilizes closer to the jet exit and along the shear layer, impeding air entrainment and thereby increasing the jet penetration depth. The flow patterns are observed to be asymmetric at elevated pressure as the flow becomes convectively unstable under non-reacting conditions. The presentation will provide insights by highlighting the physical process involved.