June 24, 2017
June 24, 2017
June 28, 2017
The standard macroscopic presentation of the second law of Thermodynamics is an elegant but abstract sequence of thought experiments that relies on very specific thought experiments that utilize reversible processes occurring within heat engines operating between infinite temperature reservoirs. These reversible processes allow no spatial variation of properties and are therefore infinitely slow and imaginary. The length, specificity and complexity of this sequence may hamper the understanding of important concepts such as exergy and entropy. Additionally, the standard sequence has been unchanged for more than a century, originating during a time when the description of local phenomena using computational approaches would have been considered science fiction. In this work, second law concepts and formulations have been derived from thought experiments that use real, rather than imaginary processes. The thought experiments involve classifying the different kinds of heat transfer at any local point for any arbitrary process involving work-heat interactions, and then collecting terms throughout the control volume in order to relate property changes to external heat transfer and/or work. They embrace the spatial non-uniformity present in any real process, are consistent with contemporary computational approaches, and can potentially serve as building blocks for the development of computational thinking in students.
Brahma, I. (2017, June), Board # 81 : Rethinking the Macroscopic Presentation of the Second Law of Thermodynamics Paper presented at 2017 ASEE Annual Conference & Exposition, Columbus, Ohio. https://peer.asee.org/27933
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