Thermo-hydraulic performance enhancement of a solar air heater using rotating cylindrical turbulators
Year of publication
2024
Authors
Singh, Sarvapriya; Suman, Siddharth; Mitra, Santanu; Kumar, Manish
Abstract
A novel concept of rotating cylindrical ribs as artificial roughness in a solar air heater to enhance its thermo-hydraulic performance factor has been investigated using 3D computational fluid dynamics. The rotational speed is varied from 2000 RPM to 10,000 RPM on the static ribs optimised for height (e), diameter (d), longitudinal pitch (P), and transverse pitch (S) at Reynolds number (Re) ranging from 5000 to 24000. The optimised static ribs configuration having e = 3.5 mm, d = 3 mm, S = 20 mm, and P/e = 10 is experimentally validated to establish the accuracy of rotating ribs performance computed using computational fluid dynamics. The maximum thermo-hydraulic performance factor of 1.89 is achieved—32 % higher than the best performance for static ribs—using rotational ribs for the rotational speed of 10,000 RPM at Re = 5000. A comparison between parallel and perpendicular orientations of rotating ribs with respect to the absorber plate establishes that perpendicular ribs configuration is highly desirable to reduce the pressure drop penalty, in turn, enhancing the thermo-hydraulic performance. The performances of the proposed perpendicularly oriented rotating cylindrical ribs are also compared with the performances reported in the literature for static ribs of different shapes having the same orientation with respect to absorber plate and it is observed that rotational ribs outperforms all the other static ribs.
Show moreOrganizations and authors
VTT Technical Research Centre of Finland Ltd
Suman Siddharth
Publication type
Publication format
Article
Parent publication type
Journal
Article type
Original article
Audience
ScientificPeer-reviewed
Peer-ReviewedMINEDU's publication type classification code
A1 Journal article (refereed), original researchPublication channel information
Journal
Volume
236
Issue
Part C
Article number
121748
ISSN
Publication forum
Publication forum level
3
Open access
Open access in the publisher’s service
Yes
Open access of publication channel
Partially open publication channel
License of the publisher’s version
CC BY
Self-archived
No
Other information
Fields of science
Mechanical engineering
Keywords
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Language
English
International co-publication
Yes
Co-publication with a company
No
DOI
10.1016/j.applthermaleng.2023.121748
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes