INVESTIGATION ON PERFORMANCE OF COMBINED ANNULAR AND LONGITUDINAL RECTANGULAR FINS ON A HORIZONTAL CYLINDER IN FREE CONVECTION

Date

2024-6-13

Author

Salamatbakhsh, Elyas

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

90
views

18
downloads

Cite This

Natural convection has wide applications in various industries. However, it has a lower heat transfer rate compared to forced convection due to lower coolant velocity. To enhance heat exchanger performance under natural convection, surface extensions known as fins are commonly employed. While unconventional fin designs offer a significant surface area and effectively disrupt the thermal boundary layer, their usage is constrained by manufacturing complexities. On the other hand, annular and longitudinal fins have extensive usage due to ease of manufacturing, simplicity, rigidity, durability, and cost-effectiveness. In the conventional air-cooled annular fin and tube units, the airflow follows a relatively direct path between the fins, with thermal performance primarily reliant on surface area. In this study, a combined annular and longitudinal fin and tube design is proposed which aims to enhance the local air velocity at the vicinity of the unit and heat transfer by deflecting airflow. An experimental setup is constructed to investigate the effects of annular fin spacing and longitudinal fin inclination angle on thermal performance, with experimental data validating the numerical simulations. Furthermore, the performance of the proposed design in an array of fin and tube units is numerically investigated. In the case of a single fin and tube unit, in the optimal annular fin spacing for maximizing the heat transfer, the heat transfer consistently decreases as the angle of the longitudinal fin increases from the vertical position, with the thermal performance always being lower than that of the conventional annular fin and tube design. However, when used in an array, the units with optimal fin spacing demonstrate up to 65% increase in heat transfer compared to an array of conventional annular fin and tube units.

Subject Keywords

natural convection, heat exchanger, CFD, heat transfer

URI

https://hdl.handle.net/11511/110079

Collections

Graduate School of Natural and Applied Sciences, Thesis