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1-D Steady-State Heat Conduction
Published in Je-Chin Han, Lesley M. Wright, Analytical Heat Transfer, 2022
It is important to point out that the temperature distribution through a fin varies depending on the aforementioned fin tip boundary conditions. In general, these temperatures decay from the fin base to the fin tip as shown in Figure 2.8. These decay curves are derived from the sinh and cosh functions shown above. In addition, the heat transfer rate through the fin depends on the temperature gradient at the fin base and the fin thermal conductivity. For example, the temperature gradient at the fin base is greater for the steel fin than the aluminum fin. However, the heat transfer rate through the fin base is higher for an aluminum fin than for a steel fin for the same fin geometry and working fluid conditions. This is because the aluminum fin has a much larger thermal conductivity than the steel fin.
Applications
Published in Raj P. Chhabra, CRC Handbook of Thermal Engineering Second Edition, 2017
Joshua D. Ramsey, Ken Bell, Ramesh K. Shah, Bengt Sundén, Zan Wu, Clement Kleinstreuer, Zelin Xu, D. Ian Wilson, Graham T. Polley, John A. Pearce, Kenneth R. Diller, Jonathan W. Valvano, David W. Yarbrough, Moncef Krarti, John Zhai, Jan Kośny, Christian K. Bach, Ian H. Bell, Craig R. Bradshaw, Eckhard A. Groll, Abhinav Krishna, Orkan Kurtulus, Margaret M. Mathison, Bryce Shaffer, Bin Yang, Xinye Zhang, Davide Ziviani, Robert F. Boehm, Anthony F. Mills, Santanu Bandyopadhyay, Shankar Narasimhan, Donald L. Fenton, Raj M. Manglik, Sameer Khandekar, Mario F. Trujillo, Rolf D. Reitz, Milind A. Jog, Prabhat Kumar, K.P. Sandeep, Sanjiv Sinha, Krishna Valavala, Jun Ma, Pradeep Lall, Harold R. Jacobs, Mangesh Chaudhari, Amit Agrawal, Robert J. Moffat, Tadhg O’Donovan, Jungho Kim, S.A. Sherif, Alan T. McDonald, Arturo Pacheco-Vega, Gerardo Diaz, Mihir Sen, K.T. Yang, Martine Rueff, Evelyne Mauret, Pawel Wawrzyniak, Ireneusz Zbicinski, Mariia Sobulska, P.S. Ghoshdastidar, Naveen Tiwari, Rajappa Tadepalli, Raj Ganesh S. Pala, Desh Bandhu Singh, G. N. Tiwari
Extended surfaces have fins attached to the primary surface on one or both sides of a two-fluid or a multifluid heat exchanger. Fins can be of a variety of geometries—plain, wavy, or interrupted—and can be attached to the inside, outside, or both sides of circular, flat, or oval tubes, or parting sheets. Fins are primarily used to increase the surface area (when the heat transfer coefficient on that fluid side is relatively low) and consequently to increase the total rate of heat transfer. In addition, enhanced fin geometries also increase the heat transfer coefficient compared to that for a plain fin. Fins may also be used on the high heat transfer coefficient fluid side in a heat exchanger primarily for structural strength purposes (e.g., for high-pressure water flow through a flat tube) or to provide a thorough mixing of a highly viscous liquid (such as for laminar oil flow in a flat or a round tube). Fins are attached to the primary surface by brazing, soldering, welding, adhesive bonding, or mechanical expansion, or they are extruded or integrally connected to the tubes. Major categories of extended surface heat exchangers are plate-fin (Figures 4.1.23 through 4.1.25) and tube-fin (Figures 4.1.26 through 4.1.28) exchangers. Note that shell-and-tube exchangers sometimes employ individually finned tubes—low-finned tubes (similar to Figure 4.1.26a but with low-height fins) (Shah, 1985).
1-D Steady-State Heat Conduction
Published in Je-Chin Han, Analytical Heat Transfer, 2016
It is important to point out that the temperature distribution through a fin varies depending on the aforementioned fin tip boundary conditions. In general, these temperatures are a decay curve from the fin base to the fin tip as shown in Figure 2.8. These decay curves are the combination of sinh and cosh functions shown above. In addition, the heat transfer rate through the fin depends on the temperature gradient at the fin base and the fin thermal conductivity. For example, the temperature gradient at the fin base is greater for the steel fin than the aluminum fin. However, heat transfer rate through the fin base is higher for an aluminum fin than for a steel fin for the same fin geometry and working fluid conditions. This is because the aluminum fin has a much larger thermal conductivity than the steel fin.
Numerical investigation on the thermal response of an unsteady magnetohydrodynamics straight porous fin
Published in International Journal of Ambient Energy, 2023
The study of heat transfer is a topic of major contemporary interest both in engineering and science. Thermal insulation engineering, solar engineering, heat storage beds, electronic cooling, geothermal power generation, heat exchangers, fiber coating, etc., are the few noteworthy applications of the heat transfer effect (Cengel and Ghajar 2015). One of the tools which help to achieve heat transfer efficiency is the usage of fins. Fins are the extended surfaces of the devices which aid to enhance heat transfer rate and they play a significant role in heat exchanging devices like heat exchangers in power plants, car radiators, etc. For instance, the regulations of heat inside the combustion chamber of automobile engines are a more critical factor without fins. It plays a major role to upgrade the heat transfer rate and therefore, excellent performance, safety, and fuel consumption of a vehicle are achieved. The convective removal of heat from a surface can be substantially improved by installing an extension on that surface. Those extensions are designed in a variety of shapes and materials on the basis of desired industrial requirements (Dwivedi and Mohan 2014 and Natrayan, Selvaraj, Alagirisamy, and Santhosh 2016). The intention of fin installation on the heat-transferring surface is not only to enhance but also to reduce the heat transfer rate depending on the demands. In several electronic and thermoelectric devices, rejecting waste heat in an economical and trouble-free way is essential.
The effect of using circular fins with a V-shaped cut on the weight reduction and the overall performance of a finned tube heat exchanger
Published in International Journal of Ambient Energy, 2022
Issam Fourar, Abdelmoumene Hakim Benmachiche
From Figure 7, we can conclude that the effect of fin thickness depends on the fin diameter and the fin material. For a material with low thermal conductivity and any fin diameter, it can be seen that there is a significant increase in the total heat transfer rate up to 170.5% when using a fin thickness of 2.5 mm instead of 0.5 mm and this is due to the increase in fin efficiency (Figure 8). On the other hand, for fins with high thermal conductivity and a small fin diameter, the change in fin thickness have almost no influence on the heat transfer. Regarding the fins with high thermal conductivity and large fin diameter, we can see that there is an increase in total heat transfer rate that reaches up to 31.4%. The increase in the total heat transfer rate is mainly due to the increase in heat transfer by conduction, which allows for better temperature distribution in the fins (Figure 8).
Analytical methods for the efficiency of annular fins with rectangular and hyperbolic profiles under partially wet surface conditions
Published in Numerical Heat Transfer, Part A: Applications, 2021
Worachest Pirompugd, Somchai Wongwises
Fins are extended surfaces used as a passive heat transfer enhancement technique. Fins enhance heat transfer rates by increasing surface area. Fins are applied to many heat transfer components such as heat sinks, evaporators, and condensers. For some equipment, the temperature of the fin surface is below the dew point, allowing the water vapor in the air to condense on the surface. As a result, heat and mass transfer take place along with air flow. Sometimes, the temperature of a fin is not uniform. Some areas may be under dry conditions while other areas are under wet conditions, or while the fin is under partially wet conditions. It is necessary to evaluate the efficiency of a fin to determine heat transfer. Schmidt [1] and Kan and Kraus [2] presented the efficiency of dry fins for longitudinal fins, spines, and circular fins. A number of researchers [1–7] have studied fin performance under fully dry conditions.