Effect of artificial roughness on heat transfer and friction factor in a solar air heater

Solar Energy ◽  
1988 ◽  
Vol 41 (6) ◽  
pp. 555-560 ◽  
Author(s):  
B.N. Prasad ◽  
J.S. Saini
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Solar Air Heater ◽  
Artificial Roughness ◽  
Air Heater

Experimental Investigation of Thermohydraulic Performance of the Solar Air Heater Having Arc-Shaped Ribs With Multiple Gaps

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Sheetal Kumar Jain ◽  
Ghanshyam Das Agrawal ◽  
Rohit Misra
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Nusselt Number ◽  
Friction Factor ◽  
Solar Air Heater ◽  
Artificial Roughness ◽  
Absorber Plate ◽  
Maximum Enhancement ◽  
Air Heater ◽  
Absorber Surface

Abstract In the present research, the thermohydraulic performance of a solar air heater having artificial roughness in the form of arc-shaped ribs with multiple gaps has been investigated experimentally and compared with that of a solar air heater having smooth absorber plate. The performance has been investigated in terms of enhancement in the Nusselt number and friction factor. Results of the present work have also been compared with previously published work. Reynolds number and arc angle (α) were varied from 3000 to 18,000 and 30 deg to 75 deg, respectively. Present roughness results in a higher rate of heat transfer from the absorber surface to air, but it also imposes a penalty in terms of the increased friction factor. Maximum enhancement in Nusselt number, friction factor, and thermohydraulic performance parameter for the roughened absorber surface is found to be 3.74, 2.69, and 2.75 times that of the smooth plate, respectively. Correlations of heat transfer and friction factor for proposed roughness have also been developed.

scholarly journals EFFECT OF ARTIFICIAL ROUGHNESS ON HEAT TRANSFER AND FRICTION CHARACTERSTICS OF DOUBLE PASS SOLAR AIR HEATER

2013 ◽  
pp. 52-56
Author(s):  
AVDHESH SHARMA ◽  
VARUN VARUN ◽  
GAURAV BHARADWAJ
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Factor ◽  
Solar Air Heater ◽  
Rectangular Duct ◽  
Artificial Roughness ◽  
Absorber Plate ◽  
Double Pass ◽  
Air Heater ◽  
Aluminium Wire

Double pass solar air heater (DPSAH) consisted of rectangular duct provided with artificial roughness on both side of the absorber plate has been experimentally investigated. Circular ribs of aluminium wire is used to provide roughness to increase heat transfer coefficient between absorber plate and air. Ribs are attached to absorber plate at four different angle of attackbetween 30° to 75° . Experiment is carried out over the range of Reynolds Number from 4900 to 12000, and relative roughness height (e/Dh) varies from 0.022 to 0.044. Experimentally different values of Nusselt number(Nu). and friction factor(fr) have been determined for various parameters. The enhance-ment in heat transfer and increment in the friction factor values of Nusselt number and friction factor have also been compared with the smooth one.

Effect of Gap Position in Broken V-rib Roughness Combined with Staggered Rib on Thermohydraulic Performance of Solar Air Heater

Green ◽  
2011 ◽  
Vol 1 (4) ◽  
Author(s):  
Anil K. Patil ◽  
J. S. Saini ◽  
K. Kumar
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Hydraulic Performance ◽  
Solar Air Heater ◽  
Artificial Roughness ◽  
Effective Technique ◽  
Air Heater ◽  
Flow Through ◽  
Absorber Surface

AbstractApplication of artificial roughness on underside of absorber surface has been found to be effective technique to improve thermo hydraulic performance of solar air heaters. In progression to the previous researches, the present study discloses the effect of broken V-rib roughness combined with staggered ribs on heat transfer and friction in a flow through artificially roughened solar air heater duct. The experimentations were performed to collect the data on heat transfer and friction by varying the Reynolds number (Re) between 3000 and 17,000, relative gap position (

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