| Summary: | 碩士 === 國立海洋大學 === 船舶機械工程學系 === 83 === This study presents the optimum design of fins at he same heat
duty and base temperature in order to obtain the smallest
volume to reach the economical consideration. First of all,
excavated fins with heat transfer at the end are investigated.
Optimum profile with the corresponding temperature distribution
is obtained when they are subject to a single mode of heat
transfer by using the method of calculus of variation. The
effects of heat transfer at fin tip and Biot number are also
quantified. Secondly, through the assumption of steady one-
dimensional analysis. Optimization is made by a numerical
method when many different heat modes coexist simultaneoly on a
fin. The boiling curve which the present model relies on
isestablished from the experimental data by others. The results
of excavated fins are compared with the solid ones and the end-
insulated fins respectively. Finally,the present model is
extended to apply in the cases of rectangular fins. The result
shows that the optimum fins proposed in the present study can
dissipate more energy than the fins with insulated tip. From
the comparison between solid and excavated fins, the
enhancement in heat transfer of the later is not so rignificant
as the former for the total area of the circumferential
surface. However, the heat transfer of unit volume is found to
be larger in the excavated fins.
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