On the correlation of heat release rate in turbulent premixed flames

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• 作者：N. Swaminathan^a ; ^{ns341@cam.ac.uk} ; R. Balachandran^b ; G. Xu^a ; ¹ ; A.P. Dowling^a
• 关键词：Combustion noise ; Premixed flames ; Sound emission from flames ; Two-point correlation
• 刊名：Proceedings of the Combustion Institute
• 出版年：2011
• 出版时间：2011
• 年：2011
• 卷：33
• 期：1
• 页码：1533-1541
• 全文大小：629 K

文摘

Two-point spatial correlation of rate of change of fluctuating heat release rate dictates the sound emission from open turbulent flames and this correlation is not directly addressed in past studies. The results from Direct Numerical Simulation and laser diagnostics of turbulent premixed flames are analyzed to study this correlation function and the two-point spatial correlation of the fluctuating heat release rate. The analyses showed that these correlation functions can be represented very well using Gaussian functions. The integral length scale, ℓ, for the fluctuating heat release rate is about one to two planar laminar flame thermal thickness, , and this is not influenced by turbulence Reynolds number and swirl. The length scale for the rate of change of fluctuating heat release rate is about . The far field sound pressure levels of open turbulent premixed flames calculated by post processing RANS simulation results along with the above length scales compare very well with measured values.