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Open AccessArticle

Entropy Generation Due to the Heat Transfer for Evolving Spherical Objects

by Ho-Young Kwak 1,2
Mechanical Engineering Department, Chung-Ang University, Seoul 06974, Korea
Blue Economy Strategy Institute Co. Ltd., Focus Buld. 23-10 Hyoryeong-ro, 60-gil, Seocho-gu, Seoul 06721, Korea
Entropy 2018, 20(8), 562;
Received: 5 July 2018 / Revised: 23 July 2018 / Accepted: 25 July 2018 / Published: 28 July 2018
(This article belongs to the Special Issue Entropy Generation and Heat Transfer)
Heat transfer accompanying entropy generation for the evolving mini and microbubbles in solution is discussed based on the explicit solutions for the hydrodynamic equations related to the bubble motion. Even though the pressure difference between the gas inside the bubble and liquid outside the bubble is a major driving force for bubble evolution, the heat transfer by conduction at the bubble-liquid interface affects the delicate evolution of the bubble, especially for sonoluminescing the gas bubble in sulfuric acid solution. On the other hand, our explicit solutions for the continuity, Euler equation, and Newtonian gravitational equation reveal that supernovae evolve by the gravitational force radiating heat in space during the expanding or collapsing phase. In this article, how the entropy generation due to heat transfer affects the bubble motion delicately and how heat transfer is generated by gravitational energy and evolving speed for the supernovae will be discussed. The heat transfer experienced by the bubble and supernovae during their evolution produces a positive entropy generation rate. View Full-Text
Keywords: bubble; heat transfer; entropy generation; lost work; supernova bubble; heat transfer; entropy generation; lost work; supernova
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Kwak, H.-Y. Entropy Generation Due to the Heat Transfer for Evolving Spherical Objects. Entropy 2018, 20, 562.

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