Mixed convection heat transfer in concave and convex channels
Abstract
Mixed convection heat transfer studies in the literature have been primarily confined to pipe and rectangular channel geometry's. In some applications, however, heat transfer in curved channels may be of interest (e.g., nozzle and diffuser shaped passages in HVAC systems, fume hoods, chimneys, bell-shaped or dome-shaped chemical reactors, etc.). A numerical investigation of laminar mixed convection heat transfer of air in concave and convex channels is presented. Six different channel aspects ratios (R/L = 1.04, 1.25, 2.5, 5, 10, and {infinity}) and five different values of Gr/Re{sup 2} (Gr/Re{sup 2} = 0, 0.1, 1, 3, 5) are considered. Results are displayed in terms of streamline and isotherm plots, velocity and temperature profiles, and local and average Nusselt number estimates. Numerical predictions reveal that compared to straight channels of equal height, concave channels of low aspect ratio have lower heat transfer at relatively low values of Gr/Re{sup 2} and higher heat transfer at high values of Gr/Re{sup 2}. When compared to straight channels of equal heated length, concave channels are always found to have lower heat transfer and for all values of Gr/Re{sup 2}. On the other hand, predictions for convex channels revealed enhancement in heat transfer compared to straight channelsmore »
- Authors:
- Publication Date:
- Research Org.:
- American Univ. of Beirut (LB)
- Sponsoring Org.:
- American University of Beirut
- OSTI Identifier:
- 20014372
- Resource Type:
- Conference
- Resource Relation:
- Conference: 32nd National Heat Transfer Conference, Baltimore, MD (US), 08/08/1997--08/12/1997; Other Information: PBD: 1997; Related Information: In: ASME proceedings of the 32nd national heat transfer conference (HTD-Vol. 346). Volume 8: Fundamentals of convection; Turbulent heat transfer; Mixed convection heat transfer, by Oosthuizen, P.H.; Chen, T.S.; Acharya, S.; Armaly, B.F.; Pepper, D.W. [eds.], 201 pages.
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; FORCED CONVECTION; NATURAL CONVECTION; CONFIGURATION; LAMINAR FLOW; NUMERICAL ANALYSIS; NUSSELT NUMBER; AUGMENTATION; THEORETICAL DATA
Citation Formats
Moukalled, F, Doughan, A, and Acharya, S. Mixed convection heat transfer in concave and convex channels. United States: N. p., 1997.
Web.
Moukalled, F, Doughan, A, & Acharya, S. Mixed convection heat transfer in concave and convex channels. United States.
Moukalled, F, Doughan, A, and Acharya, S. 1997.
"Mixed convection heat transfer in concave and convex channels". United States.
@article{osti_20014372,
title = {Mixed convection heat transfer in concave and convex channels},
author = {Moukalled, F and Doughan, A and Acharya, S},
abstractNote = {Mixed convection heat transfer studies in the literature have been primarily confined to pipe and rectangular channel geometry's. In some applications, however, heat transfer in curved channels may be of interest (e.g., nozzle and diffuser shaped passages in HVAC systems, fume hoods, chimneys, bell-shaped or dome-shaped chemical reactors, etc.). A numerical investigation of laminar mixed convection heat transfer of air in concave and convex channels is presented. Six different channel aspects ratios (R/L = 1.04, 1.25, 2.5, 5, 10, and {infinity}) and five different values of Gr/Re{sup 2} (Gr/Re{sup 2} = 0, 0.1, 1, 3, 5) are considered. Results are displayed in terms of streamline and isotherm plots, velocity and temperature profiles, and local and average Nusselt number estimates. Numerical predictions reveal that compared to straight channels of equal height, concave channels of low aspect ratio have lower heat transfer at relatively low values of Gr/Re{sup 2} and higher heat transfer at high values of Gr/Re{sup 2}. When compared to straight channels of equal heated length, concave channels are always found to have lower heat transfer and for all values of Gr/Re{sup 2}. On the other hand, predictions for convex channels revealed enhancement in heat transfer compared to straight channels of equal height and/or equal heated length for all values of Gr/Re{sup 2}.},
doi = {},
url = {https://www.osti.gov/biblio/20014372},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jul 01 00:00:00 EDT 1997},
month = {Tue Jul 01 00:00:00 EDT 1997}
}