In this paper, the results of an experimental study of laminar natural convection heat transfer and fluid flow in horizontal annuli between a cylindrical envelope and its inner concentric octagonal heated cylinder are presented. Two octagonal cylinders are investigated: one with a complete surface and the other with two horizontal slots on the top and bottom surfaces. The ratio of the slot width W to H is 0.072. Air is used as the working fluid. The range of Rayleigh number is 2.1×102–1.58×106 for the unslotted case and 1.2×102–1.5×106 for the slotted case. The average heat transfer correlations for the two cases are provided. The results show that the heat transfer intensity of the unslotted octagon is slightly weaker than that in a cylindrical annulus, while for the slotted case, the overall heat transfer enhancement may be as high as 74 percent. The smoke technique is used to visualize the flow patterns. A series of photographs of the flow patterns are provided, which enhances our understanding of the mechanism of heat transfer enhancement for the slotted octagonal case.
Skip Nav Destination
Article navigation
Research Papers
Experimental Study of Natural Convection Heat Transfer Between a Cylindrical Envelope and an Internal Concentric Heated Octagonal Cylinder With or Without Slots
H. L. Zhang,
H. L. Zhang
Department of Power Machinery Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, The People’s Republic of China
Search for other works by this author on:
Q. J. Wu,
Q. J. Wu
Department of Power Machinery Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, The People’s Republic of China
Search for other works by this author on:
W. Q. Tao
W. Q. Tao
Department of Power Machinery Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, The People’s Republic of China
Search for other works by this author on:
H. L. Zhang
Department of Power Machinery Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, The People’s Republic of China
Q. J. Wu
Department of Power Machinery Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, The People’s Republic of China
W. Q. Tao
Department of Power Machinery Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, The People’s Republic of China
J. Heat Transfer. Feb 1991, 113(1): 116-121 (6 pages)
Published Online: February 1, 1991
Article history
Received:
July 28, 1989
Revised:
March 28, 1990
Online:
May 23, 2008
Citation
Zhang, H. L., Wu, Q. J., and Tao, W. Q. (February 1, 1991). "Experimental Study of Natural Convection Heat Transfer Between a Cylindrical Envelope and an Internal Concentric Heated Octagonal Cylinder With or Without Slots." ASME. J. Heat Transfer. February 1991; 113(1): 116–121. https://doi.org/10.1115/1.2910513
Download citation file:
Get Email Alerts
Cited By
Entropic Analysis of the Maximum Output Power of Thermoradiative Cells
J. Heat Mass Transfer
Molecular Dynamics Simulations in Nanoscale Heat Transfer: A Mini Review
J. Heat Mass Transfer
Related Articles
Study of Natural Convection in an Enclosure Bounded by Two Concentric Cylinders and Two Diametric Planes
J. Heat Transfer (February,1995)
Natural Convection Heat Transfer From Long Horizontal Isothermal Cylinders
J. Heat Transfer (February,1994)
Natural Convection in a Partitioned Cubic Enclosure
J. Heat Transfer (May,1992)
Natural Convection Heat Transfer of Cold Water Within an Eccentric Horizontal Cylindrical Annulus
J. Heat Transfer (November,1988)
Related Proceedings Papers
Related Chapters
Applications
Introduction to Finite Element, Boundary Element, and Meshless Methods: With Applications to Heat Transfer and Fluid Flow
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
Finite Element Solution of Natural Convection Flow of a Nanofluid along a Vertical Flat Plate with Streamwise Sinusoidal Surface Temperature
International Conference on Computer and Electrical Engineering 4th (ICCEE 2011)