A Numerical Study of Radiative Fin Performance with an Emphasis on Geometry and Spacecraft Applications

Date of Award


Degree Name

M.S. in Department of Mechanical and Aerospace Engineering


Department of Mechanical and Aerospace Engineering


Rydge Mulford


Radiative fin technology is used in a wide variety of applications: automotive, electronics, and space. However, throughout history, radiative fin geometry is generally only analyzed along the thickness profile. This work analyzes radiative fin planar geometry and thickness profile in tandem. From there, the findings are used to investigate a novel dynamic spacecraft radiator system. Fins are analyzed to optimize for a variety of performance criteria, including maximum heat transfer, tip temperature, or fin efficiency. For analysis of both static and dynamic fins, a two-dimensional mathematical heat transfer model is developed. It is found that a triangular thickness profile is most critical for heat rate maximization. A fin with a triangular thickness profile increases heat rate by 38.8% when compared to a fin with identical planar geometry and volume, but with a uniform thickness profile. Planar shape is also found to influence fin performance. A fin with a rectangular planar geometry has a 6.8% increase in heat transfer as compared to a fin with a triangular planar geometry and identical thickness profile and volume. Additionally, it is also found that triangular thickness profiles produce the maximally efficient fins. Following these results, a novel design for a dynamic spacecraft radiator with annular geometry and varied thickness profiles is presented. It is found that turndown ratios of 3.33 are capable with the novel system. Furthermore, it was found that fins with tapered thickness profile have the highest efficiency and turndown ratio. Finally, it was shown that turndown ratio and fin efficiency decrease as operating temperature increases.


Applied Mathematics, Aerospace Engineering, Engineering, Mechanical Engineering, Radiation, Radiation, fin, fins, heat transfer, radiative fins, spacecraft, CubeSat, geometry, dynamic radiator, turndown ratio, thickness profile, planar shape

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Copyright 2021, author.