Sensitivity and Nonlinearity of Thermoacoustic Oscillations


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Authors
Juniper, MP 
Sujith, RI 
Abstract

Nine decades of rocket engine and gas turbine development have shown that thermoacoustic oscillations are difficult to predict but can usually be eliminated with relatively small ad hoc design changes. These changes can, however, be ruinously expensive to devise. This review explains why linear and nonlinear thermoacoustic behaviour is so sensitive to parameters such as operating point, fuel composition, and injector geometry. It shows how non-periodic behaviour arises in experiments and simulations and discusses how fluctuations in thermoacoustic systems with turbulent reacting flow, which are usually filtered or averaged out as noise, can reveal useful information. Finally, it proposes tools to exploit this sensitivity in the future: adjoint-based sensitivity analysis to optimize passive control designs, and complex systems theory to warn of impending thermoacoustic oscillations and to identify the most sensitive elements of a thermoacoustic system.

Description
Keywords
acoustics, flow control, instability, nonlinear dynamical systems, reacting flows, turbulent flows
Journal Title
Annual Review of Fluid Mechanics
Conference Name
Journal ISSN
0066-4189
1545-4479
Volume Title
50
Publisher
Annual Reviews, Inc.
Sponsorship
European Research Council (259620)
We would like to thank the European Research Council (ALORS 2590620), the Department of Science and Technology (DST), and the Office of Naval Research Global (ONRG) for their financial support.