Study on the mixing characteristics of circular transverse jet in crossflow

Abstract

With the development of combustion technology, transverse jets have received extensive attention, especially as the method of fuel-air mixing and flame stabilization. This paper studies circular transverse jet in crossflow and develops a new kind of transverse jet device. By injecting gas fuel into crossflow through a Laval-shaped annular gap, the device generates a circular aerodynamic barrier and forms a recirculation zone downstream the jet to obtain the flame stabilization. In this paper, numerical simulations and experimental methods are used to study the mixing characteristics of the circular transverse gas fuel jet in crossflow. The numerical simulations show that the circular transverse jet mixes quickly with crossflow in its near field region, and forms a well-mixed mixture in the recirculation zone. In the experiment, the mixing coefficient and the gas composition in the burning region were quantitatively measured. Results show that the measured excess air coefficient at each measuring point in the back half of the recirculation zone is roughly uniform and the local combustion efficiency at the end of recirculation zone approaches to 99% at atmospheric pressure and normal temperature conditions. This provides reference and basis for the research and design of circular transverse jet as fuel-air mixer and flame stabilizer.