Session: IMECE Undergraduate Research and Design Exposition

Paper Number: 114189

114189 - Thermal Performance of Dovetail Fins Under Dehumidifying Operating Conditions – Analytical and Numerical Solutions 

Extended surfaces or fins are widely used to enhance the rate of heat transfer between a solid and a surrounding fluid. The first scenario is thermal management by dissipating heat from a hot surface. The applications range from heat loss through a car radiator to the thermal management of electronic appliances by enhanced heat loss through extended surface heat sinks. The second category is for heating, ventilating, and air conditioning (HVAC) applications. The purpose of a refrigeration and air conditioning equipment is to cool the atmospheric air by passing it over an extended surface (or fin) which is at a temperature lower than the passing air. Moreover, if the fin surface temperature is below the dew point temperature of incoming moist air, then the condensation of water vapor occurs on the fin surface. Therefore, both the heat and mass transfer occur simultaneously over the fin surface. The application is commonly termed as “wet fin”.

In most applications, enhanced fin patterns (such as wavy, louver, slit, and convex louver) are adopted. However, simple fin geometries are commonly used due to low manufacturing and maintenance cost. The most common fins are longitudinal (or plane) fins, annular (or radial) fins and spines (or pin fins). A dovetail fin (i.e., variable thickness fin) can be used to enhance the performance of a double pipe heat exchanger, due to its higher surface area in comparison with the rectangular profile fin. Literature shows that the performance of a dovetail fin has been studied for heat loss function (or dry operating conditions) only and no closed form solution is available for air conditioning (i.e., wet fin) applications. The analysis of a wet fin is more challenging than the dry fin analysis because of additional consideration of mass transfer due to vapor condensation from the moist air.

The thermal performance of an extended surface is commonly described through a dimensionless parameter called fin efficiency. The current work presents a closed form solution for thermal efficiency and temperature profile of a dovetail fin that accounts for the combined heat and mass transfer under dehumidification operating conditions. The developed solution is a general case that covers rectangular, tapered and triangular fins. The solution is validated through available closed form solutions of rectangular and triangular fins. Comparison of results with a two-dimensional finite element numerical solution provided the limit of one-dimensional solution for a dovetail fin. Preliminary results show that dovetail fin has higher thermal efficiency than the rectangular and triangular fins.

Presenting Author: Pornphiphat Saiboonchan Texas A&M University Texarkana

Presenting Author Biography: P. Saiboonchan is an excellent mechanical engineering undergraduate student and holds the Best Student Award for the AY 2021-22. During summer 2022, under supervision of a professor of physics at TAMUT, he participated in a collaborative research project with Rice University. They worked on developing a metallic compound for studying its magnetic properties

Authors:

Pornphiphat Saiboonchan Texas A&M University Texarkana
Sulaman Pashah Texas A&M University Texarkana