Natural convection and conduction in massive wall solar collectors with honeycomb and without vents

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · Journal of Solar Energy Engineering

DOI:https://doi.org/10.1115/1.2847766· OSTI ID:118739

Lakhal, E K ^[1]; Bilgen, E; Vasseur, P ^[2]

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1. Semlalia, Marrakesh (Morocco)
2. Ecole Polytechnique, Montreal, Quebec (Canada)

Steady heat transfer by natural convection and conduction is numerically studied in passive solar collector systems consisting of a massive wall with honeycomb structure and without vents. The boundary conditions are constant heat flux on the wall and fins, isothermal on the vertical bounding sides, and adiabatic on the horizontal sides. The governing parameters are the Rayleigh number (10{sup 6} {le} Ra {le} 5 {times} 10{sup 9}), the aspect ratio of the enclosures (0.4 {le} A = H{prime}/L{prime} {le} 1.4), the dimensionless lengths of the fins (0 {le} B = l{prime}/L{prime}{sub 1} {le} 1), the aspect ratio of the microcavities (0.05 {le} C = h{prime}/L{prime} {le} 1), the wall thickness (0.008 {le} w = w{prime}/L{prime} {le} 0.033). The fin thickness (e = e{prime}/H{prime} = 0.06) and the Prandtl number (Pr = 0.72) were constant, and the conductivity ratio was variable (10{sup {minus}4} {le} k{sub r} {le} 5 {times} 10{sup 6}). Local and average Nusselt numbers along the long sides are calculated as a function of various parameters. Streamlines and isotherms are produced. Effects of various parameters on the heat transfer are examined and heat transfer correlations are derived.

• Sponsoring Organization: USDOE
• OSTI ID: 118739
• Journal Information: Journal of Solar Energy Engineering, Journal Name: Journal of Solar Energy Engineering Journal Issue: 3 Vol. 117; ISSN JSEEDO; ISSN 0199-6231
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
NATURAL CONVECTION
PASSIVE SOLAR HEATING SYSTEMS
SOLAR ARCHITECTURE
THERMAL CONDUCTION
THERMAL INSULATION
THERMAL MASS