Control of Instabilities in Liquid Fueled Combustor by Modification of the Reaction Zone Using Smart Fuel Injector

This paper describes an experimental investigation of suppressing combustion instabilities in a liquid fueled (n-heptane) atmospheric combustor incorporating an array of “smart” fuel injectors. These injectors were designed so that their spray properties could be manipulated without changing the overall operating conditions (power, mass flow rates, equivalence ratio, etc.) of the combustor. In this paper, the stability characteristics of a combustor incorporating seven such smart injectors were determined. Additionally, high speed photography was used to provide visualization of the different modes of instabilities, and suppression of instabilities in this combustor by slow tuning of the injector spray properties was demonstrated.