Both analytical and numerical calculations are performed to study the buoyancy effect on the reversed flow structure and heat transfer processes in a finite vertical duct with a height to spacing ratio of 12. One of the walls is heated uniformly and the opposite wall is adiabatic. Uniform air flow is assumed to enter the duct. In the ranges of the buoyancy parameter of interest here for both assisted and opposed convection, a reversed flow, which can be observed to initiate in the downstream close to the exit, propagates upstream as increases. The increase in the Reynolds number has the effect of pushing the reversed flow downstream. Simple analytical models are developed to predict the penetration depth of the reversed flow for both assisted and opposed convection. The models can accurately predict the penetration depth when the transport process inside the channel is dominated by natural convection. Local and average Nusselt numbers at different buoyancy parameters are presented. Comparison with the experimental data published previously was also made and discussed. Good agreement confirms many of the numerical predictions despite simplifications of the numerical process made, such as two-dimensional and laminar flow assumptions.
Skip Nav Destination
e-mail: gauc@mail.ncku.edu.tw
Article navigation
Research Papers
Numerical and Analytical Study of Reversed Flow and Heat Transfer in a Heated Vertical Duct
C. S. Yang,
C. S. Yang
Department of Computer Science and Information Engineering,
Far East University
, Hsin-Shih, Tainan County 744, Taiwan
Search for other works by this author on:
D. Z. Jeng,
D. Z. Jeng
Aeronautics Research Laboratory,
Chung-Shan Institute of Science and Technology
, Taichung, Taiwan
Search for other works by this author on:
K. A. Yih,
K. A. Yih
Institute of Aeronautics and Astronautics and Center for Micro/Nano Science and Technology,
National Cheng Kung University
, Tainan 70101, Taiwan
Search for other works by this author on:
C. Gau,
C. Gau
Institute of Aeronautics and Astronautics and Center for Micro/Nano Science and Technology,
e-mail: gauc@mail.ncku.edu.tw
National Cheng Kung University
, Tainan 70101, Taiwan
Search for other works by this author on:
Win Aung
Win Aung
Institute of Aeronautics and Astronautics and Center for Micro/Nano Science and Technology,
National Cheng Kung University
, Tainan 70101, Taiwan
Search for other works by this author on:
C. S. Yang
Department of Computer Science and Information Engineering,
Far East University
, Hsin-Shih, Tainan County 744, Taiwan
D. Z. Jeng
Aeronautics Research Laboratory,
Chung-Shan Institute of Science and Technology
, Taichung, Taiwan
K. A. Yih
Institute of Aeronautics and Astronautics and Center for Micro/Nano Science and Technology,
National Cheng Kung University
, Tainan 70101, Taiwan
C. Gau
Institute of Aeronautics and Astronautics and Center for Micro/Nano Science and Technology,
National Cheng Kung University
, Tainan 70101, Taiwane-mail: gauc@mail.ncku.edu.tw
Win Aung
Institute of Aeronautics and Astronautics and Center for Micro/Nano Science and Technology,
National Cheng Kung University
, Tainan 70101, TaiwanJ. Heat Transfer. Jul 2009, 131(7): 072501 (9 pages)
Published Online: May 5, 2009
Article history
Received:
June 21, 2008
Revised:
February 3, 2009
Published:
May 5, 2009
Citation
Yang, C. S., Jeng, D. Z., Yih, K. A., Gau, C., and Aung, W. (May 5, 2009). "Numerical and Analytical Study of Reversed Flow and Heat Transfer in a Heated Vertical Duct." ASME. J. Heat Transfer. July 2009; 131(7): 072501. https://doi.org/10.1115/1.3109998
Download citation file:
Get Email Alerts
Cited By
Estimation of thermal emission from mixture of CO2 and H2O gases and fly-ash particles
J. Heat Mass Transfer
Non-Classical Heat Transfer and Recent Progress
J. Heat Mass Transfer
Related Articles
On Natural Convective Heat Transfer in Vertical Channels With a Single Surface Mounted Heat-Flux Module
J. Heat Transfer (August,2003)
Prediction of Nusselt Number and Flow Rate of Buoyancy Driven Flow Between Vertical Parallel Plates
J. Heat Transfer (February,2004)
Transient Double Diffusive Convection in a Vertical Enclosure With Asymmetrical Boundary Conditions
J. Heat Transfer (August,2000)
The Dynamics of Two-Dimensional Buoyancy Driven Convection in a Horizontal Rotating Cylinder
J. Heat Transfer (December,2004)
Related Proceedings Papers
Related Chapters
Applications
Introduction to Finite Element, Boundary Element, and Meshless Methods: With Applications to Heat Transfer and Fluid Flow
Mixed-Up Convection
Hot Air Rises and Heat Sinks: Everything You Know about Cooling Electronics Is Wrong
Cooling of Steel Spherical Balls by Natural Convection and Radiation Heat Transfer in Unsteady State
Electromagnetic Waves and Heat Transfer: Sensitivites to Governing Variables in Everyday Life