Direct numerical simulation of the near field dynamics of a rectangular reactive plume


Jiang, X. and Luo, K.H. (2001) Direct numerical simulation of the near field dynamics of a rectangular reactive plume. International Journal of Heat and Fluid Flow, 22, (6), 633-642. (doi: 10.1016/S0142-727X(01)00123-0).

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Description/Abstract

Spatial direct numerical simulation (DNS) is used to study the near field dynamics of a buoyant diffusion flame established on a rectangular nozzle with an aspect ratio of 2:1. Combustion is represented by a one-step finite-rate Arrhenius chemistry. Without applying external perturbations at the inflow boundary, large vortical structures develop naturally in the flow field, which interact with the flame and temporally create localized holes within the reaction zone in which no chemical reactions take place. The interaction between density gradients and gravity plays a major role in the vorticity generation of the buoyant plume. At the downstream of the reactive plume, a more disorganized flow regime characterized by small scales has been observed, following the breakdown of the large vortical structures due to three-dimensional (3D) vortex interactions. Analysis of energy spectra shows that the spatially developing reactive plume has a tendency of transition to turbulence under the effects of combustion-induced buoyancy. The buoyancy effects are found to be very important to the formation, development, interaction, and breakdown of vortices in reactive plumes. In contrast with the relaminarization effects of chemical exothermicity via viscous damping and volumetric expansion on non-buoyant jet diffusion flames, the tendency towards transition to turbulence in reactive plumes is greatly enhanced by the buoyancy effects.

Item Type: Article
Additional Information: The paper presented a fundamental study of interactions among flow instabilities, vortex dynamics, turbulence and combustion using cutting-edge direct numerical simulation. New findings were obtained regarding effects of buoyancy and combustion on flow transition. Cited by Goldstein RJ, Eckert ERG, Ibele WE, et al. (2003) in ``Heat Transfer – a Review of 2001 Literature’’ Intl. J. Heat and Mass Transfer 46 (11): 1887-1992. Journal impact factor 1.013.
ISSNs: 0142-727X (print)
Related URLs:
Keywords: DNS, buoyancy, transition, combustion, non-circular jets
Subjects: T Technology > T Technology (General)
Q Science > QD Chemistry
Divisions: University Structure - Pre August 2011 > School of Engineering Sciences
University Structure - Pre August 2011 > School of Engineering Sciences > Thermofluids and Superconductivity
ePrint ID: 23103
Date Deposited: 16 Mar 2006
Last Modified: 27 Mar 2014 18:12
Contact Email Address: K.H.Luo@soton.ac.uk
URI: http://eprints.soton.ac.uk/id/eprint/23103

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