0
RESEARCH PAPERS: Natural and Mixed Convection

Observations of Spanwise Symmetry Breaking for Unsteady Mixed Convection in Horizontal Ducts

[+] Author and Article Information
R. E. Spall

Department of Mechanical Engineering, University of South Alabama, Mobile, M 36688

J. Heat Transfer 118(4), 885-888 (Nov 01, 1996) (4 pages) doi:10.1115/1.2822584 History: Received December 04, 1995; Revised August 01, 1996; Online December 05, 2007

Abstract

Three-dimensional mixed convection in a horizontal rectangular duct heated from below was studied numerically for a non-Boussinesq fluid. The duct was of aspect ratio four, with cold side-wall boundary conditions. Results were obtained at a reduced temperature of 2.33, Rayleigh number of 130,700, and Reynolds numbers of 5 and 20. Using the Re = 20 solution as initial conditions, the Re = 5 solution developed asymmetries about the duct centerline plane, with a streamwise periodic generation and dissolution of the inner pair of vortices. The consequence of these coherent vortical structures was a complex time-dependent distribution of the Nusselt number on the lower wall, with implications in the area of chemical vapor deposition. Specifically, when compared with the steady flow case occurring at Re = 20, an increased spatial uniformity of the time-averaged Nusselt number along the lower duct surface resulted.

Copyright © 1996 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In