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Title:
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Nanoscale thermal systems in subcritical region |
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Author:
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Hos, Pascal |
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Advisor:
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Bayazitoglu, Yildiz |
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Degree:
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Doctor of Philosophy thesis |
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Abstract:
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The behavior of a nanoscale fluid system in the subcritical region is investigated using molecular simulation. The fluid used is argon and the intermolecular forces are represented by the Lennard-Jones potential. The simulations show that the phase change in a nanoscale system becomes continuous as opposed to the constant temperature and constant pressure phase change for a macroscale system. Then nonlinear curve fitting was performed using two cubic equations to obtain a representation of the simulation data.
The continuous phase change behavior predicted by the molecular simulation is verified by using an approximate analytical analysis. A cubical system is defined for five different configurations based on the minimization of the interfacial surface area. These systems are then analyzed to define their thermodynamic behavior by using a technique to minimize the Helmholtz free energy.
It is also shown how this continuous phase change alters the behavior of nanoscale thermal systems in subcritical thermodynamic cycles. A nanoscale vapor heat engine shows a lower efficiency than the macroscale vapor heat engine and the coefficient of performance for a nanoscale refrigeration cycle is higher than that for a macroscale refrigeration cycle. |
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Citation:
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Hos, Pascal. "Nanoscale thermal systems in subcritical region." Doctoral Thesis, Rice University, ETD http://hdl.handle.net/1911/17976. |
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Citable link to this page:
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http://hdl.handle.net/1911/17976 |
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Date:
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2001 |
