Summary: | 碩士 === 國立成功大學 === 系統及船舶機電工程學系 === 107 === A three-dimensional shape design problem is considered in this thesis to determine the optimal snowflake-shaped fins (SSF), based on the minimization of maximum domain temperature of fin under fixed fin volume constraint. The Levenberg-Marquardt method (LMM) coupled with software package CFD-ACE+ are used as the design tools. The SSF can be obtained by modifying the helm-shaped fins (HSF), the fine surfaces of HSF can be increased by splitting central part of the extended bodies from the center line outward and perforations can therefore be formed, and thus the maximum temperature of the fin can be reduced. The objective of this work is to estimate the optimal design variables of SSF such that they can minimize the maximum fin temperature. The validity of CFD-ACE+ is first performed to verify the accuracy of the numerical solutions, and two categories of test cases. i.e. single internal heat source (IHS) problems and multiple IHS problems, in determining the optimal SSF are examined in the present study. The estimated optimal SSF are then compared with the HSF given by Feng et al [23]. Results indicate that the optimal SSF can achieve lower maximum fin temperature than HSF.
|