Heat transfer and friction factor correlations for a solar air heater duct roughened artificially with multiple v-ribs

Journal Article · Tue Jun 15 04:00:00 EDT 2010 · Solar Energy

DOI:https://doi.org/10.1016/J.SOLENER.2010.02.004· OSTI ID:21320545

Hans, V S ^[1]; Saini, R P ^[2]; Saini, J S ^[3]

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1. Department of Mechanical Engineering, PAU, Ludhiana (Punjab) 141004 (India)
2. Alternate Hydro Energy Centre, Indian Institute of Technology, Roorkee (UA) 247667 (India)
3. Mechanical and Industrial Engineering Department, Indian Institute of Technology, Roorkee (UA) 247667 (India)

The use of artificial roughness on the underside of the absorber plate is an effective and economic way to improve the thermal performance of a solar air heater. Several experimental investigations, involving different types of roughness elements, have been carried out to improve the heat transfer from the absorber plate to air flowing in solar air heaters. This paper presents an experimental investigation carried out to study the effect of multiple v-rib roughness on heat transfer coefficient and friction factor in an artificially roughened solar air heater duct. The experiment encompassed Reynolds number (Re) from 2000 to 20000, relative roughness height (e/D) values of 0.019-0.043, relative roughness pitch (P/e) range of 6-12, angle of attack ({alpha}) range of 30-75 and relative roughness width (W/w) range of 1-10. Extensive experimentation has been conducted to collect data on heat transfer and fluid flow characteristics of a rectangular duct roughened with multiple v-ribs. Using these experimental data, correlations for Nusselt number and friction factor in terms of roughness geometry and flow parameters have been developed. (author)

• OSTI ID: 21320545
• Journal Information: Solar Energy, Journal Name: Solar Energy Journal Issue: 6 Vol. 84; ISSN 0038-092X; ISSN SRENA4
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
AIR
CORRELATIONS
DUCTS
EXPERIMENTAL DATA
FLUID FLOW
FRICTION FACTOR
GEOMETRY
HEAT TRANSFER
HEIGHT
Multiple v-ribs
NUSSELT NUMBER
PERFORMANCE
PLATES
REYNOLDS NUMBER
ROUGHNESS
SOLAR AIR HEATERS
WIDTH