Thermo-acoustic behavior of a swirl stabilized diffusion flame with heterogeneous sensors

TitleThermo-acoustic behavior of a swirl stabilized diffusion flame with heterogeneous sensors
Publication TypeJournal Article
Year of Publication2013
AuthorsSingh AV, Yu M, Gupta AK, Bryden KM
Journal TitleApplied Energy
Date Published06
Type of ArticleArticle
ISBN Number0306-2619
Accession NumberWOS:000317544400001
KeywordsAcoustics, CFD, Heterogeneous sensor system, LES, noise, RANS, Swirl, Temperature fluctuations, temperature-measurements, Thermal time scales, thermocouples, Turbulent diffusion flame

Next generation combustors are expected to be significantly more efficient while reducing pollutants and eliminating carbon emissions. In such combustors, the challenges of local flow, pressure, chemical composition and thermal signatures as well as their interactions require understanding to seek for optimum performance of the system. The current practice of using a single sensor to measure certain parameters at a single location cannot provide sufficient information to achieve desirable and optimum overall performance of the combustor. A high density sensor network with a large number of sensors will be required in future smart combustors to obtain detailed information on the various ongoing processes within the system. As an initial step towards the development of such sensor networks, the effect of mean and fluctuating temperature distribution on the distribution of acoustic sources within the flame has been examined by using a thermocouple and condenser microphone using swirl stabilized diffusion flames. The measurement of high frequency temperature signal allowed observation of characteristic mean and fluctuating temperatures, and thermal stratification characteristics from within the flame. Specifically mean and fluctuating temperatures, integral and micro-thermal time scales have been determined at various spatial locations in the flame. Investigation of the thermal field and their effect on the localization of acoustic sources in the two flames formed at different equivalence ratios has been examined. The thermal characteristics data obtained provided a better insight on the thermal behavior of co-swirl diffusion flames. Noise spectra for varying air-fuel ratios were determined. Results of time average and fluctuating temperature and sound pressure level spectra showed noise emission in flames to lie near to the regions of high temperature which result in pressure fluctuations within the flame. The results are complemented with 3D CFD simulations that supported the localization of the acoustic sources within the turbulent diffusion flames. (C) 2013 Elsevier Ltd. All rights reserved.

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