Entropy generation analysis of laminar film condensation inside an elliptical tube

• Main Authors: Wen Chung Lung, 溫純龍
• Other Authors: Kuo Chun Hsien
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/9qfk6d

碩士 === 國立高雄應用科技大學 === 模具系碩士在職專班 === 101 === The paper aims to analyze the second law of thermodynamics on a saturated vapor slowly onto an elliptical tube laminar film condensation heat transfer problems. Based on Bejan entropy generation method, the dependence of the local and average entropy generation rate on Rayleigh number, Jakob number, Brinkman number and irreversibility ratio is investigated numerically. The entropy generation technical analysis is applied to an elliptical tube laminar film condensation heat transfer to find that entropy generation is caused mainly by heat transfer and film flow friction. The results of this paper provide different geometric eccentricities by tilting a elliptical tube to identify the impact factors of laminar film condensation heat transfer process of entropy generation. From the second law point of view, entropy generation increases with increasing the value of ellipticity. When eccentricity becomes larger, the cooling efficiency is better.