Experimental and numerical investigations of jet active control for combustion applications

Abstract

Controlling the mixing of a gas (usually fuel) issuing from a tube into surrounding air is a basic problem in multiple combustion systems. The purpose of the present work is to develop an actuator device to control the mixing enhancement of an axisymmetric non-reactive jet. The actuators consist of four small jets feeding the primary jet flow. These four jets are oriented to add an azimuthal component to the velocity field. The influence of the jets' deflection and position along the main jet duct is discussed. Schlieren photographs and planar laser-induced fluorescence measurements are used to compare the efficiency of the three configurations of interest. The effect of ‘control-to-main’ mass flow rates' ratio is quantified through hot wire anemometry results. Large eddy simulations (LES) of both forced and unforced configurations are also performed. The objectives of the numerical part of this work are to understand the actuator effect and to validate LES as a tool to study active control.

This paper was chosen from Selected Proceedings of the Third International Symposium on Turbulence and Shear Flow Phenomena (Sendai, Japan, 24-27 June 2003).