Investigation of Heat Transfer and Entropy Generation of Natural Convection in Gambrel Roof
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Date
2022
Authors
Ogwumike, T.E.
Olakoyejo, O.T.
Musah, A.A.
Oloruntoba, O.T.
Oyekeye, M.O.
Journal Title
Journal ISSN
Volume Title
Publisher
UJESR
Abstract
A numerical study has been executed for a 2D laminar natural convection in Gambrel roof with boundary conditions that depict a hot weather climate in Nigeria. A commercial numerical code is used to model the design conditions. As a result of symmetry of the Gambrel roof geometry, half of the roof is used to carry out the study. The inclined roof and bottom roof surfaces are kept isothermally heated and cooled respectively, while the vertical surface at the symmetry line is kept adiabatic. Air is used as the coolant in this analysis. The effects of base ( ) and top ( ) pitch angles and Rayleigh number (Ra) on the heat transfer and entropy generation characteristics are investigated. The results are presented by Nusselt number (Nu), entropy generation, isotherms and streamlines. Isotherms are seen to be smooth and uniform
at lower Ra, while they undergo distortion at higher Ra. When the pitch angles are fixed, the effect of Ra on the Nu is not significant until Ra 105 , after which the relationship between Ra and Nu is becomes clearly linear. At fixed Ra, reducing causes an increase in total entropy generation and Nu while increasing the causes a slight increase in the Nu. The physical implication of this is that at fixed Ra, the best convective heat transfer process is achieved by reducing and increasing . This study would prove useful to designers in improving the thermal comfort of buildings with the Gambrel roof for a summer climate condition.
Description
Scholarly article
Keywords
Natural convection , Pitch angle , Nusselt number , Entropy generation , Research Subject Categories::TECHNOLOGY::Engineering mechanics
Citation
Ogwumike, T.E., Olakoyejo, O.T., Musah, A.A., Oloruntoba, O.T. and Oyekeye, M.O. (2022). Investigation of Heat Transfer and Entropy Generation of Natural Convection in Gambrel Roof, Uniport Journal of Engineering and Scientific Research vol 6(2), 24-33