Understanding the thermodynamic properties of the elastocaloric effect through experimentation and modelling
| Autor: | Eduard Vives, Jaka Tušek, Kurt Engelbrecht, Lluís Mañosa, Nini Pryds |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Thermodynamics
superelastičnost 02 engineering and technology 01 natural sciences Isothermal process Thermodynamic cycle superelasticity 0103 physical sciences elastocaloric effect General Materials Science Maxwell relations Adiabatic process COP 010302 applied physics shape memory alloy isothermal entropy change Fundamental thermodynamic relation Chemistry Shape-memory alloy adiabatic temperature change 021001 nanoscience & nanotechnology udc:697:621.577(045) zlitine z oblikovnim spominom Mechanics of Materials Direct methods elektrokalorični učinek Pseudoelasticity 0210 nano-technology |
| Zdroj: | Shape memory and superelasticity, vol. 2, no. 4, pp. 317-329, 2016. |
| Popis: | This paper presents direct and indirect methods for studying the elastocaloric effect (eCE) in shape memory materials and its comparison. The eCE can be characterized by the adiabatic temperature change or the isothermal entropy change (both as a function of applied stress/strain). To get these quantities, the evaluation of the eCE can be done using either direct methods, where one measures (adiabatic) temperature changes or indirect methods where one can measure the stress–strain–temperature characteristics of the materials and from these deduce the adiabatic temperature and isothermal entropy changes. The former can be done using the basic thermodynamic relations, i.e. Maxwell relation and Clausius–Clapeyron equation. This paper further presents basic thermodynamic properties of shape memory materials, such as the adiabatic temperature change, isothermal entropy change and total entropy–temperature diagrams (all as a function of temperature and applied stress/strain) of two groups of materials (Ni–Ti and Cu–Zn–Al alloys) obtained using indirect methods through phenomenological modelling and Maxwell relation. In the last part of the paper, the basic definition of the efficiency of the elastocaloric thermodynamic cycle (coefficient of performance) is defined and discussed. |
| Databáze: | OpenAIRE |
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