Jiang, Xi 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). pp. 633-642. ISSN 0142-727XFull text not available from this repository.
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. (C) 2001 Elsevier Science Inc. All rights reserved.
|Journal or Publication Title:||International Journal of Heat and Fluid Flow|
|Uncontrolled Keywords:||DNS ; buoyancy ; transition ; combustion ; non-circular jets ; JET DIFFUSION FLAMES ; SQUARE JETS ; BOUNDARY-CONDITIONS ; NONCIRCULAR JETS ; BUOYANT PLUMES ; THERMAL PLUME ; TURBULENCE ; FLOWS ; COMBUSTION ; TRANSITION|
|Departments:||Faculty of Science and Technology > Engineering|
|Deposited On:||21 Nov 2011 11:44|
|Last Modified:||07 Jan 2015 17:02|
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