Heat Transfer Analysis of a Solar Air Heater Roughened with Chamfered Rib and Groove Roughness on the Absorber Plate Using CFD Approach

Influences of arc-shaped baffles turbulators (ASB) on thermal behaviors in a solar air heater channel are studied. In the experiment, the ASB with three pitch ratios (P/e) are placed on the absorber plate (bottom channel wall in this case) to generate stronger turbulence intensity in the channel. The distributions of temperature and local Nusselt number contours in the absorber plate fitted with ASB are observed with thermochromic liquid crystal (TLC) sheet. The results reveal that the heat transfer increases with the decrease in P/e due to longitudinal vortex flow effect. The heat transfer from employing the ASB at P/e = 4.0, 6.0 and 8.0 is higher than the smooth channel around 116%, 120% and 127%, respectively. This indicates that the ASB pitch spacing is optimal at 8 times baffle height in the present work.

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NUMERICAL INVESTIGATION OF HEAT TRANSFER COEFFICIENT AND FRICTION FACTOR OF SOLAR AIR HEATER PROVIDED WITH ISOSCELES RIGHT TRIANGLE RIB ROUGHNESS ON THE ABSORBER PLATE

JP Journal of Heat and Mass Transfer ◽

10.17654/hm014010069 ◽

2017 ◽

Vol 14 (1) ◽

pp. 69-96 ◽

Cited By ~ 1

Author(s):

Rajeev Ranjan ◽

M. K. Paswan ◽

N. Prasad ◽

R. V. Sharma

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Friction Factor ◽

Numerical Investigation ◽

Solar Air Heater ◽

Absorber Plate ◽

Air Heater

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Experimental Studies on a Solar Air Heater Having V-Corrugated Absorber Plate with Obstacles Bent Vertically

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.493.86 ◽

2014 ◽

Vol 493 ◽

pp. 86-92 ◽

Cited By ~ 5

Author(s):

Ekadewi A. Handoyo ◽

Djatmiko Ichsani ◽

Prabowo ◽

S. Sutardi

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Flat Plate ◽

Air Temperature ◽

Temperature Rise ◽

Experimental Studies ◽

Bottom Plate ◽

Solar Air Heater ◽

Absorber Plate ◽

Air Heater

A solar air heater (SAH) is a simple heater using solar radiation that is useful for drying or space heating. Unfortunately, heat transfer from the absorber plate to the air inside the solar air heater is low. Some researchers reported that obstacles are able to improve the heat transfer in a flat plate solar air collector and others found that a v-corrugated absorber plate gives better heat transfer than a flat plate. Yet, no work of combining these two findings is found.This paper describes the result of experimental study on a SAH with v-corrugated absorber plate and obstacles bent vertically started from 80oto 0owith interval 10oon its bottom plate. Experiments were conducted indoor at five different Reynolds numbers (1447 Re 7237) and three different radiation intensities (430, 573, and 716 W/m2).It is found that the obstacles improve SAH performance. Both the air temperature rise and efficiency increase with inserting obstacles bent at any angle vertically. Unfortunately, the air pressure drop is increasing, too. Obstacles bent vertically at smaller angle (means more straight) give higher air temperature rise and efficiency. However, the optimum angle is found 30o. The air temperature rise and efficiency will be 5.3% lower when the obstacles bent 30oinstead of 0o, but the pressure drop will be 17.2% lower.

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