Flow-acoustic Characterisation of a Cavity-based Combustor Configuration

Agarwal, Krishna Kant and Ravikrishna, RV (2011) Flow-acoustic Characterisation of a Cavity-based Combustor Configuration. In: Defence Science Journal, 61 (6). pp. 523-528.

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Abstract

This study concerns the flow-acoustic characterisation of a cavity-based combustor configuration. A well-validated numerical tool has been used to simulate the unsteady, two-dimensional reacting flow. Initially, a conventional flow over a cavity with dimensions and conditions corresponding to a compact cavity combustor was studied. Cavity mass injections in the form of fuel and air injections required for trapped vortex formation were then employed and the resonance features of this configuration were studied. The results indicate that the cavity depth mode resonance mechanism is dominant at the conditions studied in this work and that the oscillation frequencies do not change with cavity air injection. This observation is important since it implies that the only important variable which can alter resonant frequencies is the cavity depth. With combustion, the pressure oscillation amplitude was observed to increases significantly due to periodic entrainment of the cavity air jet and fluctuation of fuel-air mixture composition to produce highly fluctuating heat-release rates. The underlying mechanisms of the unsteady flow in the cavity combustor identified in this study indicate the strong dependence of the acoustics on the cavity injection strategies.

Item Type:	Journal Article
Publication:	Defence Science Journal
Publisher:	Defence Research & Development Organisation, India
Additional Information:	Copyright of this article belongs to Defence Research & Development Organisation, India.
Keywords:	Flow-acoustics;cavity combustor;turbulent reacting flow; unsteady flow;cavity fluid mechanics
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	30 Jan 2012 08:59
Last Modified:	30 Jan 2012 09:01
URI:	http://eprints.iisc.ac.in/id/eprint/43169

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