Title: Vortex structure and heat transfer in a diffusion combustion field with circulating flow

Authors: Hideo Kawahara, Tatsuo Nishimura

Addresses: Shipping Technology Department, Oshima National College of Maritime Technology, 1091-1 Komatsu, Suo-Oshima-cho, Oshima-gun, Yamaguchi-prefecture 742-2193, Japan. ' Department of Mechanical Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube-City, Yamaguchi-prefecture 755-8611, Japan

Abstract: A numerical study was performed to examine the vortical structures for combusting flow from a two-dimensional bluff-body slot burner in the transitional recirculating flow. The numerical results support the flow visualisation results for C₃H₈ combustion by Chin and Tankin [Chin, L.P. and Tankin, R.S. (1991) |Vortical structures in a 2-d vertical bluff-body burner|, Combustion Science and Technology, Vol. 80, pp.207–229]. We identify the fuel effect on the dynamic vortical structures inside the flame for C₃H₈ and CH₄ fuels. The Reynolds number for the inner slot fuel flow is varied from 10–250 at a fixed Reynolds number of 400 for the outer slot air flow. As a result of the study on a two-dimensional bluff-body burner, it was possible to reproduce the dynamic motions of vortical structures obtained by Chin and Tankin visualisation experiment. In the low Reynolds number region, vortex structures in the recirculating region gives large effect in the flame form. In addition, it was confirmed that independently of the fuel variety, the flow at the bluff-body aft comes into three shape varieties.

Keywords: bluff-body slot burner; dynamic motion; flame effect; fuel effect; gaseous fuel; recirculating flow; transition; vortex structure; heat transfer; diffusion combustion; flow visualisation.

DOI: 10.1504/IJETP.2008.017027

International Journal of Energy Technology and Policy, 2008 Vol.6 No.1/2, pp.17 - 30

Published online: 04 Feb 2008 *

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