Evaluation of strain-rate effects in transitional round jets using direct numerical simulation

Mathew, Joseph (1998) Evaluation of strain-rate effects in transitional round jets using direct numerical simulation. In: Symposium (International) on Combustion, 27 (1). pp. 1207-1212.

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Abstract

The coherent flame model uses the strain rate to predict reaction rate per unit flame surface area and some procedure that solves for the dynamics of flame surfaces to predict species distributions. The strainrate formula for the reaction rate is obtained from the analytical solution for a flame in a laminar, plane stagnation point flow. Here, the formula's effectiveness is examined by comparisons with data from a direct numerical simulation (DNS) of a round jetlike flow that undergoes transition to turbulence. Significant differences due to general flow features can be understood qualitatively: Model predictions are good in the braids between vortex rings, which are present in the near field of round jets, as the strain rate is extensional and reaction surfaces are isolated. In several other regions, the strain rate is compressive or flame surfaces are folded close together. There, the predictions are poor as the local flow no longer resembles the model flow. Quantitative comparisons showed some discrepancies. A modified, consistent application of the strain-rate solution did not show significant changes in the prediction of mean reaction rate distributions.

Item Type:	Journal Article
Publication:	Symposium (International) on Combustion
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier science.
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited:	09 Jun 2011 07:22
Last Modified:	09 Jun 2011 07:22
URI:	http://eprints.iisc.ac.in/id/eprint/38112

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