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Persistent URL http://purl.org/net/epubs/work/25589
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Record Id 25589
Title On the local constitutive convolution and graph theoretical representations of thermodynamic processes
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Abstract A thermodynamic processes can be represented as either a local constitutive relationship or as a directed graph network. It is demonstrated that only the local constitutive equations yield, for all cases considered, the correct values for the physical properties of the materials under test, whereas the directed graph network representations are unreliable. This is because the directed graph network representations can be ill posed and likely to lead to erroneous values for the transport coefficients. The local constitutive equations allow the measurement of the linear and nonlinear transport properties under dynamical conditions. The response function values are estimated directly from the time series data of the physical observables and the area under the response function is equal to the equilibrium transport coefficient value. The nonlinear temporal form of the multidimensional convolution representation is also given and used to estimate the linear and nonlinear thermal transport coefficients of materials with low thermal conductivities. The nonlinear analysis shows that the one dimensional thermal conductive transport is linear within the experimental uncertainties for a range of material types whose conductivity spans three orders of magnitude.
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Language English (EN)
Type Details URI(s) Local file(s) Year
Report RAL Technical Reports RAL-93-089. 1993. RAL-TR-1993-089.pdf 1993