A mixing enhancement mechanism for a hydrogen transverse jet coupled with a shear layer for gas turbine combustion

Abstract

The mixing characteristics of hydrogen and air are vital to combustion performance. Excellent hydrogen-air mixing is required to avoid hot spots in the reactivity of hydrogen in a combustion chamber. The present study aims to explore a mixing enhancement mechanism for a hydrogen transverse jet in which a rib is added in front of the jet. A schlieren technique is used to visualize the flow field of the improved hydrogen jet, and the combustion performance of the improved flame stabilizer is studied. The results show that the penetration depth and mixing performance of the hydrogen jet are improved. At its outset, the hydrogen jet flows like a free jet downstream of the rib. The flow pattern of the hydrogen jet is then changed by the shear layer between the low-velocity region and the mainstream. Ideal mixing performance is ultimately achieved under the strong effect of the mainstream. Combustion experiments show that the mixing and combustion performance is greatly improved by the rib in front of the jet. This study provides an important theoretical basis for the design of gaseous fuel combustors.