Active Control of Coaxial Jet Mixing and Combustion with Axisymmetric and Non-axisymmetric Mode Excitations

Abstract

Coaxial jet mixing and combustion are actively controlled through manipulation of the vortical structures and the associated mixing with twelve micro jet actuators installed on the annular nozzle. The different azimuthal mode examined here are the fundamental axisymmetric mode and the alternative mode. In the alternative mode, six adjacent micro jets are driven out-of-phase with the other six. The alternative mode provides a phase difference in the generation of the left and right side vortices and avoids interference between these vortices, so that larger vortices are developed if compared to the axisymmetric mode. The effect of the different azimuthal modes on the mixing and the exhaust gas characteristics are discussed.