Effect of cross-flow momentum on opposing jet mixing

Abstract

The flow of opposing jets was studied in computational fluid dynamics simulation. To clarify the flow field of the jet engine combustor, it is necessary to study air-jet dilution effects typical of opposing jets. The velocity distribution and turbulence intensity were obtained in large eddy simulation for air and an average Reynolds number of 2 × 104 corresponding to the jet diameter and velocity. Results obtained numerically generally agreed quantitatively with experimental results obtained in our previous study. Simulations were then carried out to clarify the effect of the momentum flux ratio J (4, 9, 16, and 64) on mixing. Unmixedness was found to be highest for J = 4 since the penetrations and thus collision of opposing jets were weak for J = 4. When J = 9, 16, 64, mixing was improved by jet collision. It is proposed that the mixing mechanisms are differed depending on J.