eprintid: 1332314
rev_number: 46
eprint_status: archive
userid: 608
dir: disk0/01/33/23/14
datestamp: 2011-11-30 15:28:04
lastmod: 2021-10-18 00:02:20
status_changed: 2012-11-02 16:29:50
type: article
metadata_visibility: show
item_issues_count: 0
creators_name: Swaminathan, N
creators_name: Xu, G
creators_name: Dowling, AP
creators_name: Balachandran, R
title: Heat release rate correlation and combustion noise in premixed flames
ispublished: pub
divisions: UCL
divisions: B04
divisions: C05
divisions: F45
keywords: acoustics, reacting flows, turbulent reacting flows, INLET VELOCITY OSCILLATIONS, ACOUSTIC RADIATION, NONLINEAR RESPONSE, SOUND GENERATION, VALIDATION, TURBULENCE, SPEED, MODEL, JET
note: © 2011 Cambridge University Press
abstract: The sound emission from open turbulent flames is dictated by the two-point spatial correlation of the rate of change of the fluctuating heat release rate. This correlation in premixed flames can be represented well using Gaussian-type functions and unstrained laminar flame thermal thickness can be used to scale the correlation length scale, which is about a quarter of the planar laminar flame thermal thickness. This correlation and its length scale are observed to be less influenced by the fuel type or stoichiometry or turbulence Reynolds and Damkohler numbers. The time scale for fluctuating heat release rate is deduced to be about tau(c)/34 on an average, where tau(c) is the planar laminar flame time scale, using direct numerical simulation (DNS) data. These results and the spatial distribution of mean reaction rate obtained from Reynolds-averaged Navier-Stokes (RANS) calculations of open turbulent premixed flames employing the standard (k) over tilde-(epsilon) over tilde model and an algebraic reaction rate closure, involving a recently developed scalar dissipation rate model, are used to obtain the far-field sound pressure level from open flames. The calculated values agree well with measured values for flames of different stoichiometry and fuel types, having a range of turbulence intensities and heat output. Detailed analyses of RANS results clearly suggest that the noise level from turbulent premixed flames having an extensive and uniform spatial distribution of heat release rate is low.
date: 2011-08
publisher: CAMBRIDGE UNIV PRESS
official_url: http://dx.doi.org/10.1017/jfm.2011.232
vfaculties: VENG
oa_status: green
language: eng
primo: open
primo_central: open_green
article_type_text: Article
verified: verified_manual
elements_source: Web of Science
elements_id: 340844
doi: 10.1017/jfm.2011.232
language_elements: EN
lyricists_name: Balachandran, Ramanarayanan
lyricists_id: RBALA57
full_text_status: public
publication: J FLUID MECH
volume: 681
pagerange: 80 - 115
issn: 0022-1120
citation:        Swaminathan, N;    Xu, G;    Dowling, AP;    Balachandran, R;      (2011)    Heat release rate correlation and combustion noise in premixed flames.                   J FLUID MECH , 681    80 - 115.    10.1017/jfm.2011.232 <https://doi.org/10.1017/jfm.2011.232>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1332314/1/download4.pdf