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arXiv 1808.07698cond-mat.stat-mechphysics.comp-phphysics.flu-dyn
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热相分离中的熵产生:动力学理论方法

Entropy production in thermal phase separation: a kinetic-theory approach

Yudong Zhang, Aiguo Xu, Guangcai Zhang, Yanbiao Gan, Zhihua Chen, Sauro Succi

摘要:

采用离散Boltzmann动力学模型研究了多相流热相分离过程中的熵产生。的熵产生率被发现在失稳分解阶段增加,并在畴生长阶段减少,达到最大值在两者之间的交叉。这种行为为识别和区分这两种制度提供了一个自然标准。此外,通过系统地探讨非平衡能量和动量通量之间的相互作用,研究了导热系数,粘度和表面张力对熵产生率的影响。结果表明,由于能量通量的熵产生率是普朗特数的增函数,而动量通量则表现出相反的趋势。另一方面,这两个贡献都表现出随表面张力增加的趋势。目前的分析内的非平衡态热力学的一般框架内,因此,它预计将是有关的软流动系统远离机械和热平衡的广泛类别。

英文摘要:

Entropy production during the process of thermal phase-separation of multiphase flows is investigated by means of a discrete Boltzmann kinetic model. The entropy production rate is found to increase during the spinodal decomposition stage and to decrease during the domain growth stage, attaining its maximum at the crossover between the two. Such behaviour provides a natural criterion to identify and discriminate between the two regimes. Furthermore, the effects of heat conductivity, viscosity and surface tension on the entropy production rate are investigated by systematically probing the interplay between non-equilibrium energy and momentum fluxes. It is found that the entropy production rate due to energy fluxes is an increasing function of the Prandtl number, while the momentum fluxes exhibit an opposite trend. On the other hand, both contributions show an increasing trend with surface tension. The present analysis inscribes within the general framework of non-equilibrium thermodynamics and consequently it is expected to be relevant to a broad class of soft-flowing systems far from mechanical and thermal equilibrium.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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