Buoyancy-assisted flow reversal and convective heat transfer in entrance region of a vertical rectangular duct

✍ Scribed by Chin-Hsiang Cheng; Chun-Jen Weng; Win Aung

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 672 KB
• Volume: 21
• Category: Article
• ISSN: 0142-727X
• DOI: 10.1016/s0142-727x(00)00005-9

✦ Synopsis

In this study, predictions of buoyancy-assisted ¯ow reversal and convective heat transfer in the entrance region of a vertical rectangular duct are reported for the ®rst time. In line with the current trend toward the use of computationally ecient numerical methods, the present study is based on the use of a three-dimensional parabolic, boundary-layer model and the FLARE approximation. Physical situations investigated include cases with various asymmetric heating conditions over wide ranges of parameters. Analytical solutions for the fully developed ¯ows are also presented, and the criteria for the ¯ow reversal to occur are predicted. Solutions for the developing ¯ow obtained in this study agree closely with the elliptic-model solutions, and precisely approach the fully developed solutions downstream.