Modulation of a Liquid-Fuel Jet in an Unsteady Cross-Flow

Abstract

This paper describes an experimental study of a fuel jet in an unsteady cross flow as part of a program to evaluate active control of combustion instabilities that involve acoustic / spray coupling. The results provide insights into the different physical mechanisms through which the jet and cross flow interact and the degree to which acoustic velocity fluctuations modulate liquid jet mixing, penetration and spray distribution. They also provide a means of evaluating the effectiveness of fuel flow modulation for controlling fuel jet behavior, demonstrating that fluctuations in the downstream spray distribution can be significantly reduced by phased fuel flow modulation. The paper describes a unique method for modulating the fuel and a relatively simple diagnostic for evaluating the fuel spray density and uniformity.