numerical simulation of two-dimensional fin efficiency in joined fin with inline tubes

• Main Authors: Jui-Ting Fan, 范瑞廷
• Other Authors: Li-Ting Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/51844573646663803504

碩士 === 國立清華大學 === 動力機械工程學系 === 90 === The aim of my thesis is to study the temperature distribution and fin efficiency of the joined-fin whose tubes arranged inline. When the coolant running in a heat exchanger, the tubes in the same sheet of fin have different temperatures. Consequently, it causes the condition of different base (tube) temperatures in one sheet of fin. In this condition, the temperature distribution of the fin is influenced by the ambient temperature and different tubes temperatures. The finite difference approximation was used to simulate the two-dimensional temperature distribution and to calculate mean fin efficiency under the different tubes temperatures condition. The simulation results were then compared with the Schmidt method, which is widely used to calculate the fin efficiency. The result reveals that there is difference between Schmidt method and the method presented in the study when the equivalent radius over the radius of the tube is bigger. Besides, when air passed through the heat exchanger, the airflow heat exchanged with the extend surface, and it also caused the change of air temperature. In addition, the changes of the air temperature in the procedure were shown in the other simulation. The effects of the coolant running in parallel flow and counter flow were discussed.