水平平板流之熱質傳遞影響熵增值之研究

摘要本文探討微粒沉積於平板時所對熵增值造成之影響。熵的產生是由熱和質量傳遞過程在一多層流體流經平板中推導出來，由於熱和質量傳遞之間的結合所造成之熵的產生為研究的方向之一，研究的目的在研究在流體流經一水平平板，質量和熱傳遞影響熵值產生的現象。以不同的史密數及溫差來探討對熵增值的影響效應及最小熵增值時之平板長度，結果顯示當史密數越來越大時則其熵增值越來越小，另當平板表面溫度小於流體溫度時，溫差愈大，其熵的增值率愈大。

關鍵字

熱質傳遞；吹出參數；熵增值；熱泳係數

並列摘要

ABSTRACT This thesis discusses the influence of entropy generation when particles deposit on the flat plate. Entropy generation is from flow over a flat plate due to heat and mass transfers. This is one of the basic studies for entropy generation resulting from coupling of heat and mass transfers. The mass and heat transfers are induced from flow over the flat plate. The influence and phenomenon as a result of entropy generation are the purpose of investigation in this study. Results show discusses the effects from the entropy generation for the flow over a flat plate under different Schmidt number and temperature. Also, the minimum entropy generation and the optimal flat plate length are examined. The results of the numerical are found that the entropy generation decreases with a increasing in the Schmidt number. In addition, a increasing in temperature difference, when the surface temperature of plate is less than the flow temperature causes the increase in entropy generation ratio.

並列關鍵字

Entropy Generation ； Thermophortic coefficient ； Blowing number ； Heat and Mass Transfers

參考文獻

【1】A. Bejan, A study of entropy generation in fundmental convective heat transfer, ASME J. Heat Transfer 101, 718-125 (1979).

【2】A. Bejan, Second law analysis in heat transfer, Energy 5, 721-732 (1980).

【3】A. Bejan, The concept of irreversibility in heat exchanger design: counterflow heat exchangers for gas-to-gas applications, ASME J. Heat Transfer 99, 374-380 (1977).

【4】A. Bejan, Two thermodynamic optima in the design of sensible heat units for energy storage, ASME J. Heat Transfer 100, 708-712 (1978).

【7】J. O. Hirschfelder, C . F. Curtiss and R. B. Bird, Molecular Theory of Gases and Liquids, Wiley, New York (1954).

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水平平板流之熱質傳遞影響熵增值之研究

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