Natural convection heat transfer in moderate aspect ratio enclosures

Journal Article · Thu Nov 01 04:00:00 EST 1979 · J. Heat Transfer; (United States)

DOI:https://doi.org/10.1115/1.3451052· OSTI ID:5645639

Meyer, B A; Mitchell, J W; El-Wakil, M M

Local and average heat transfer coefficients for natural convection between parallel plates separated by slats to create enclosures of moderate aspect ratio have been experimentally determined using an interferometric technique. The effects of Rayleigh number, tilt and slat angle, and aspect ratio on the Nusselt number have been determined. The Rayleigh number range tested was up to 7 x 10/sup 4/, and the aspect ratio (ratio of enclosure length to plate spacing) varied between 0.25 and 4. The angles of tilt of the enclosure with respect to the horizontal were 45, 60 and 90 deg. Slat angles of 45, 60 90 and 135 deg were studied. The results obtained in a previous investigation (1) for aspect ratios of 9 to 36 are included to show continuity. The results indicate that the convective heat transfer is a strong function of the aspect ratio for aspect ratios less than 4. For aspect ratios in the range of 0.5 to 4, spacers between the plates increase, rather than decrease, natural convection heat transfer compared to that for long enclosures. Slat angles less than 90 deg (i.e., oriented downward) reduce convective heat transfer.

• Research Organization: Mechanical Engineering Department, The University of Wisconsin, Madison, Wisc. 53706
• OSTI ID: 5645639
• Journal Information: J. Heat Transfer; (United States), Journal Name: J. Heat Transfer; (United States) Vol. 101:4; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ASPECT RATIO
CONVECTION
INTERFEROMETRY
NATURAL CONVECTION
NUSSELT NUMBER
PLATES