Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater

A literature review carried out by the authors reveals that that a CFD analysis has not been the focus of attention to evaluate the efficacy of turbulators for improving the thermal performance of solar air heaters. A three dimensional CFD analysis is carried out in the present work to augment the performance of solar air heater. Arc shaped wire turbulators (with forward and reverse curvature aligned with flow direction), V-shaped wire turbulators (with forward and reverse geometry with respect to the flow direction) and Straight turbulators are used in this study to improve the flow turbulence and thereby enhance the convective heat transfer to air. The numerical results are validated with experimental results for model without turbulator to calibrate the numerical methodology. The numerical results show that turbulators whether curved or straight are useful in enhancing the heat transfer rates. The Arc shaped turbulators have been found to provide better heat transfer coefficient value compared to that of straight and V-shape turbulators. Also interestingly, Reverse arc turbulators seems to provide better heat transfer coefficient value compared to forward arc turbulators. Further, V-angle has no significant effect for both forward and reverse V-turbulator configurations.

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A Review on Heat Transfer Enhancement of Solar Air Heater Using Various Artificial Roughed Geometries

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.89.1.92133 ◽

2021 ◽

Vol 89 (1) ◽

pp. 92-133

Author(s):

Sudharani Panda ◽

Rakesh Kumar

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Heated Surface ◽

Cost Effective ◽

Solar Air Heater ◽

Artificial Roughness ◽

Air Heater

Solar air heater acts as one of the important components in utilization of solar energy. The air heater absorbs the irradiance and converts it into heat energy at the absorbing surface. The thermal energy is further use in heating flowing air through the duct. Solar air heaters are cost effective as well as simple in design. Solar air heater can be used in space heating, timber seasoning and agricultural drying. In spite of all these advantages the solar air heater has certain challenges such as the air has low heat transfer coefficient. The heat transfer rate from the heated absorber surface to the air is low. Hence in order to enhance the heat transfer coefficient the surface area either increases or the flow made to be turbulent. In order to do so the artificial roughened element must be incorporated on the heated surface. The use of artificial roughness is considered as an effective technique to enhance the heat transfer rate of fluid flowing through the duct of solar air heater. The heat transfer and friction characteristics of number of roughness geometries incorporated solar air heater have been investigated. In this paper an attempt has been made to review on element geometries used as artificial roughness in solar air heater in order to improve thermal and thermo hydraulic performance of solar air heater ducts.

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Performance Analysis of Solar Air Heater using CFD Simulation

International Journal of Thermal Technologies ◽

10.14741/ijtt/v.8.1.2 ◽

2018 ◽

Vol 8 (01) ◽

Author(s):

Ambreesh Prasad Shukla ◽

Rakesh Kushwaha ◽

Bhupendra Gupta ◽

Anand Bisen

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Solar Energy ◽

Transfer Coefficient ◽

Cfd Simulation ◽

Solar Air Heater ◽

Outlet Temperature ◽

Absorber Plate ◽

Air Heater ◽

Research Article

Solar energy has emerged as one of the alternate to conventional sources of energy. Solar air heaters are one of the important devices to utilize solar energy. But, poor heat transfer coefficient is one of the major problem in solar air heater. In this research article, an attempt is made to increase heat transfer coefficient of solar air heater by putting Hollow bodies over the absorber plate. These resulted in increase in heat transfer coefficient, efficiency and increase in outlet temperature of air simultaneously

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