Table of Contents
Journal of Thermodynamics
Volume 2015, Article ID 949384, 9 pages
http://dx.doi.org/10.1155/2015/949384
Research Article

Thermoacoustic Instability in a Rijke Tube with a Distributed Heat Source

1School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, P.O. Box 88, Manchester M60 1QD, UK
2Thermal Management Research Group, Efficient Energy Transfer Department (ηET), Bell Labs, Alcatel-Lucent, Dublin 15, Ireland

Received 7 July 2015; Revised 8 October 2015; Accepted 12 October 2015

Academic Editor: Philip De Goey

Copyright © 2015 Xiaochuan Yang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A Rijke tube with a distributed heat source is investigated. Driven by the widely existing thermoacoustic instability in lean premixed gas turbine combustors, this work aims to explore the physicochemical underpinning and assist in the elucidation and analysis of this problem. The heat release model consists of a row of distributed heat sources with individual heat release rates. The integrated heat release rate is then coupled with the acoustic perturbation for thermoacoustic analysis. A continuation approach is employed to conduct the bifurcation analysis and capture the nonlinear behaviour inherent in the system. Unlike the conventional approach by the Galerkin method, the acoustic equations are originally discretized using the Method of Lines (MOL) to build up a dynamic system. The model is first validated and shown to yield good predictions with available experimental data. Influences of multiple heat sources, time delay, and heat release distribution are then studied to reveal the extensive nonlinear characteristics involved in the case of a distributed heat source. It is found that distributed heat source plays an important role in determining the stability of a thermoacoustic system.