Loss of chaos in combustion noise as a precursor of impending combustion instability

Nair, Vineeth ; Thampi, Gireehkumaran ; Karuppusamy, Sulochana ; Gopalan, Saravanan ; Sujith, R. I. (2013) Loss of chaos in combustion noise as a precursor of impending combustion instability International Journal of Spray and Combustion Dynamics, 5 (4). pp. 273-290. ISSN 1756-8277

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Official URL: http://journals.sagepub.com/doi/abs/10.1260/1756-8...

Related URL: http://dx.doi.org/10.1260/1756-8277.5.4.273

Abstract

Combustion noise has been traditionally thought of as stochastic fluctuations present in the background of the dynamics in combustors amongst the flow, heat release and the chamber acoustics. Through a series of determinism tests, we show that these aperiodic fluctuations are in fact chaotic of moderately high dimensions (d0 ≅ 8–10). These chaotic fluctuations then transition to high amplitude combustion instability when the operating conditions are varied towards leaner equivalence ratios. Precursors to such a transition from chaos to dynamics dominated by periodic oscillations are of interest to designers and operators of combustors in estimating the boundaries of operability. We introduce a test for chaos, known as 0–1 test for chaos in the literature, as a measure of the proximity of the combustor to an impending instability. The measure is robust and shows a smooth transition for variation in flow conditions towards instability enabling thresholds to be set for operational boundaries.

Item Type:Article
Source:Copyright of this article belongs to SAGE Publications.
ID Code:109975
Deposited On:21 Dec 2017 10:55
Last Modified:21 Dec 2017 10:55

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