Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation AnalysisReport as inadecuate




Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis - Download this document for free, or read online. Document in PDF available to download.

Journal of Combustion - Volume 2014 2014, Article ID 280671, 29 pages -

Research Article

School of Mechanical and Systems Engineering, Newcastle University, Claremont Road, Newcastle-Upon-Tyne NE1 7RU, UK

Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK

Received 5 December 2013; Accepted 31 January 2014; Published 3 April 2014

Academic Editor: Michael Fairweather

Copyright © 2014 Y. Gao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The statistical behaviours of the instantaneous scalar dissipation rate of reaction progress variable in turbulent premixed flames have been analysed based on three-dimensional direct numerical simulation data of freely propagating statistically planar flame and V-flame configurations with different turbulent Reynolds number . The statistical behaviours of and different terms of its transport equation for planar and V-flames are found to be qualitatively similar. The mean contribution of the density-variation term is positive, whereas the molecular dissipation term acts as a leading order sink. The mean contribution of the strain rate term is predominantly negative for the cases considered here. The mean reaction rate contribution is positive negative towards the unburned burned gas side of the flame, whereas the mean contribution of the diffusivity gradient term assumes negative positive values towards the unburned burned gas side. The local statistical behaviours of , , , , , and have been analysed in terms of their marginal probability density functions pdfs and their joint pdfs with local tangential strain rate and curvature . Detailed physical explanations have been provided for the observed behaviour.





Author: Y. Gao, N. Chakraborty, and N. Swaminathan

Source: https://www.hindawi.com/



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