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arXiv · 2206.09715

Evaluating the Gouy-Stodola Theorem in Classical Mechanic Systems: A Study of Entropy Generation

R. H. Longaresi·S. D. Campos
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Abstract

We propose to apply the entropy generation $(\dot S_{gen}$) concept to a mechanical system: the well-known simple pendulum. When considering the ideal case, where only conservative forces act on the system, one has $\dot S_{gen}=0$, and the entropy variation is null. However, as shall be seen, the time entropy variation is not null all the time. Considering a non-conservative force proportional to the pendulum velocity, the amplitude of oscillations decreases to zero as $t$ grows. In this case, $\dot S_{gen}>0$ indicates that it is related to energy dissipation, as stated by the Gouy-Stodola theorem. Hence, as shall be seen, the greater the strength of the non-conservative force, the greater are both the energy dissipation and the time rate of entropy variation.

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R. H. Longaresi, S. D. Campos. 2022-06-20. Evaluating the Gouy-Stodola Theorem in Classical Mechanic Systems: A Study of Entropy Generation. https://doi.org/10.1142/s2661339522500184

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