Experimental measurements of heat transfer coefficient in a partially/fully opened tilted cavity

Journal Article · Sat Nov 01 04:00:00 EST 1997 · Journal of Solar Energy Engineering

DOI:https://doi.org/10.1115/1.2888036· OSTI ID:590137

Chakroun, W; Elsayed, M M; Al-Fahed, S F ^[1]

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1. Kuwait Univ. (Kuwait). Mechanical and Industrial Engineering Dept.

An experimental investigation was carried out to determine the heat transfer coefficient from a rectangular tilted cavity to the ambient due to the buoyancy driven flow in the cavity. The cavity is partially or fully open from one side. All the walls of the cavity are adiabatic except the wall facing the cavity opening which is heated at a constant heat flux. Air was used as the cavity fluid and the experiments were carried out at a flux Grashof number of 5.5 {times} 10{sup 8}. The tilt angle of the cavity, measured from the vertical direction, was changed between {minus}90 deg to +90 deg in 15 deg increments. Also, geometries of aspect ratio (height-to-width of cavity) of 1.0, 0.5, and 0.25 and of opening ratio (opening height to cavity height) of 1.0, 0.5, and 0.25 were considered in the study. The results are presented in terms of the average Nusselt number for different values of the above experimental parameters. Conclusions are derived for the effect of changing the tilt angle, the aspect ratio, or the opening ratio of the cavity on the average heat transfer coefficient between the cavity and the ambient air. Buoyancy-driven flow in rectangular cavities has been widely investigated by many researchers. This geometry is of special interest in many solar applications such as in solar passive heating, solar concentrators, and solar central receivers. The importance of the geometry extends to other engineering applications such as electronic equipment, fire research, and energy conservation in buildings.

• Sponsoring Organization: USDOE
• OSTI ID: 590137
• Journal Information: Journal of Solar Energy Engineering, Journal Name: Journal of Solar Energy Engineering Journal Issue: 4 Vol. 119; ISSN JSEEDO; ISSN 0199-6231
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
42 ENGINEERING
CAVITIES
CENTRAL RECEIVERS
HEAT TRANSFER
PARAMETRIC ANALYSIS
PASSIVE SOLAR HEATING SYSTEMS
SOLAR CONCENTRATORS