TY - JOUR
T1 - Natural convection between two horizontal cylinders inside a circular enclosure subjected to external convection
AU - Ho, C. J.
AU - Cheng, Y. T.
AU - Wang, C. C.
N1 - Funding Information:
The authors gratefully acknowledge the support for the present study from the National Science Council of the Republic of China through project NSC 81-0401-E006-03. The constructive comments of the reviewers leading to improvement of the earlier manuscript are sincerely appreciated.
PY - 1994/8
Y1 - 1994/8
N2 - This paper presents a numerical study, supplemented with experiments of flow visualization and holographic interferometric measurement, concerning the buoyancy-induced fluid flow and heat transfer between two horizontal, differentially heated cylinders inside a circular, air-filled enclosure subjected to external convection. Numerical simulations via a finite-difference method have been conducted mainly to investigate the effect of insulation (namely, the external convection boundary condition) at the circular enclosure wall on the buoyant air flow structure and heat transfer characteristics among the horizontal cylinders and the circular enclosure wall. The results are displayed graphically to emphasize the effects of the Rayleigh number (Ra = 104∼107), the inclination angle of the enclosure with respect to gravity (φg = 30, 60, 90°) and the gap width between the horizontal cylinders (s/d = 0.7, 0.8333, 1.0) in the presence of external convection. The external convection at the circular enclosure wall was found to further promote buoyant convection flow and a markedly enhanced heat transfer between the cylinders accordingly results. In addition, the simulation taking account for the external convection at the enclosure wall was found to compare favorably with the experimental results of flow visualization and temperature distribution in a test cell with imperfect thermal insulation.
AB - This paper presents a numerical study, supplemented with experiments of flow visualization and holographic interferometric measurement, concerning the buoyancy-induced fluid flow and heat transfer between two horizontal, differentially heated cylinders inside a circular, air-filled enclosure subjected to external convection. Numerical simulations via a finite-difference method have been conducted mainly to investigate the effect of insulation (namely, the external convection boundary condition) at the circular enclosure wall on the buoyant air flow structure and heat transfer characteristics among the horizontal cylinders and the circular enclosure wall. The results are displayed graphically to emphasize the effects of the Rayleigh number (Ra = 104∼107), the inclination angle of the enclosure with respect to gravity (φg = 30, 60, 90°) and the gap width between the horizontal cylinders (s/d = 0.7, 0.8333, 1.0) in the presence of external convection. The external convection at the circular enclosure wall was found to further promote buoyant convection flow and a markedly enhanced heat transfer between the cylinders accordingly results. In addition, the simulation taking account for the external convection at the enclosure wall was found to compare favorably with the experimental results of flow visualization and temperature distribution in a test cell with imperfect thermal insulation.
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U2 - 10.1016/0142-727X(94)90015-9
DO - 10.1016/0142-727X(94)90015-9
M3 - Article
AN - SCOPUS:0028486592
VL - 15
SP - 299
EP - 306
JO - Heat Fluid Flow
JF - Heat Fluid Flow
SN - 0142-727X
IS - 4
ER -