Thermal performance and exergy analysis in a round tube with louvered trapezoidal winglets
| dc.contributor.author | Promvonge, Pongjet | |
| dc.contributor.author | Eiamsa-ard, Smith | |
| dc.contributor.author | Skullong, Sompol | |
| dc.contributor.author | Maruyama, Naoki | |
| dc.contributor.author | Hirota, Masafumi | |
| dc.date.accessioned | 2026-08-06T10:42:22Z | |
| dc.date.available | 2026-08-06T10:42:22Z | |
| dc.date.issued | 2023-09-15 | |
| dc.description.abstract | An experiment was performed to investigate the influence of inserting a louver-punched trapezoidal-winglet (LPTW) into a uniform heat-fluxed tube in order to create a longitudinal vortex generator. This research aims to maximize both the thermal performance to increase energy savings, and the relative Nusselt number (Nu<inf>R</inf>) at the optimal performance to reduce heat exchanger sizes. Therefore, the experimental result was emphasized on the thermal and pressure loss characteristics including entropy, and exergy analysis of the turbulent tube flow for Reynolds numbers (Re) that extended from 4760 to 29,280. The LPTWs were arranged by letting V-tip direct downstream with three attack angles (α = 30°, 45° and 60°) and five louver angles (θ<inf>1</inf> = 0°, 25°, 30°, 45° and 90°), all at a single relative winglet pitch (P<inf>R</inf> = 1.0) and height (B<inf>R</inf> = 0.25). According to the findings, it revealed that the friction factor (f) and Nusselt number (Nu) of the LPTW at α= 60° and θ<inf>1</inf> = 0° are, respectively, up to 29.1 and 5.5 times above those of the plain tube. With decreasing Re and θ<inf>1</inf>, the entropy generation (S˙<sup>′</sup><inf>gen</inf>) was reduced to a lower value and the maximum exergy efficiency (η<inf>Ex</inf>) was obtained for the LPTW at α = 60° and θ<inf>1</inf> = 0° The peak thermal performance around 2.5 together with Nu<inf>R</inf> = 4.68 was found at a= 60°, θ<inf>1</inf> = 45° and the lowest Re. However, the optimal condition at α= 60°, θ<inf>1</inf> = 30° was preferable because it provides the greatest Nu<inf>R</inf> = 5.04 at TEF = 2.47. Additionally, correlations for f and Nu were derived and presented for the range of parameters that were taken into consideration. | |
| dc.identifier.citation | International Journal of Heat and Mass Transfer, 212, 2023 | |
| dc.identifier.doi | 10.1016/j.ijheatmasstransfer.2023.124261 | |
| dc.identifier.issn | 00179310 | |
| dc.identifier.other | 2-s2.0-85159229868 | |
| dc.identifier.uri | https://dspace.kmitl.ac.th/handle/123456789/14643 | |
| dc.source | International Journal of Heat and Mass Transfer | |
| dc.subject | Entropy generation | |
| dc.subject | Exergy efficiency | |
| dc.subject | Heat exchanger | |
| dc.subject | Thermal performance | |
| dc.subject | Vortex generator | |
| dc.title | Thermal performance and exergy analysis in a round tube with louvered trapezoidal winglets | |
| dc.type | Article |