TY - JOUR ID - discovery1332314 SN - 0022-1120 N1 - © 2011 Cambridge University Press JF - J FLUID MECH EP - 115 AV - public N2 - 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. VL - 681 UR - http://dx.doi.org/10.1017/jfm.2011.232 SP - 80 KW - acoustics KW - reacting flows KW - turbulent reacting flows KW - INLET VELOCITY OSCILLATIONS KW - ACOUSTIC RADIATION KW - NONLINEAR RESPONSE KW - SOUND GENERATION KW - VALIDATION KW - TURBULENCE KW - SPEED KW - MODEL KW - JET TI - Heat release rate correlation and combustion noise in premixed flames A1 - Swaminathan, N A1 - Xu, G A1 - Dowling, AP A1 - Balachandran, R Y1 - 2011/08// PB - CAMBRIDGE UNIV PRESS ER -