Skip to main content
×
Home
    • Aa
    • Aa

Heat release rate correlation and combustion noise in premixed flames

  • N. SWAMINATHAN (a1), G. XU (a1), A. P. DOWLING (a1) and R. BALACHANDRAN (a2)
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 τc/34 on an average, where τc 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 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.

Copyright
Corresponding author
Email address for correspondence: ns341@cam.ac.uk
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

R. W. Bilger 1993 In Turbulence and Molecular Processes in Combustion (ed. T. Takeno ), pp. 267285. Elsevier.

K. N. C. Bray 1980 Turbulent flows with premixed reactants. In Turbulent Reacting Flows (ed. P. A. Libby & F. A. Williams ), pp. 115183. Springer.

D. G. Crighton , A. P. Dowling , J. E. F. Williams , M. Heckl & F. G. Leppington 1992 Modern Methods in Analytical Acoustics: Lecture Notes, chap. Thermoacoustic sources and instabilities, pp. 387405. Springer.

N. Peters 2000 Turbulent Combustion. Cambridge University Press.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Fluid Mechanics
  • ISSN: 0022-1120
  • EISSN: 1469-7645
  • URL: /core/journals/journal-of-fluid-mechanics
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×
MathJax

Keywords:

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 57 *
Loading metrics...

Abstract views

Total abstract views: 205 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 26th June 2017. This data will be updated every 24 hours.