Theoretical studies on optimum circular and longitudial fins

• Main Authors: Fan ,Chen-Jyh, 范振智
• Other Authors: Chih-Pin Liaw;Rong-Hua Yeh
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/71695575561232297939

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.