Efficient designs of double-pass curved solar air heaters

Kumar, A.; Akshayveer; Singh, A.P.; Singh, O.P.

dc.contributor.author	Kumar, A.
dc.contributor.author	Akshayveer
dc.contributor.author	Singh, A.P.
dc.contributor.author	Singh, O.P.
dc.date.accessioned	2020-11-17T11:44:50Z
dc.date.available	2020-11-17T11:44:50Z
dc.date.issued	2020-11
dc.identifier.issn	09601481
dc.identifier.uri	http://localhost:8080/xmlui/handle/123456789/904
dc.description.abstract	Recent research has shown that flat plate double-pass solar air heaters (DPSAH) exhibit higher thermal performance compared to conventional flat plate single-pass solar air heaters (SPSAH). However, scientific literature on design and performance evaluation of a curved DPSAH is scarce. In this paper, we systematically investigated various designs of DPSAH and reported its performance characteristics using a validated numerical model. Higher outlet air temperature by about 5 °C was observed when the DPSAH absorber plate is located at the mid of the insulating wall and transparent glass cover. Furthermore, putting asymmetric semi-circular roughened surfaces shows better performance than symmetric circular shapes as the reattachment of vortices with the absorber plate is more frequent in the former case. Two new correlations were developed for Nusselt number (Nu) and friction factor (f) as a function of Reynolds number (Re) and relative roughness height (d/H). The values of Nu and f obtained from the developed correlations agree well with data from the model. © 2020 Elsevier Ltd	en_US
dc.language.iso	en_US	en_US
dc.publisher	Elsevier Ltd	en_US
dc.relation.ispartofseries	Renewable Energy;Vol. 160
dc.subject	Curved solar air heater	en_US
dc.subject	Double-pass	en_US
dc.subject	Computational fluid dynamics	en_US
dc.subject	Relative roughness ratio	en_US
dc.subject	Nusselt number	en_US
dc.title	Efficient designs of double-pass curved solar air heaters	en_US
dc.type	Article	en_US