We determine how the natural distributions of phonon-phonon and phonon-boundary scattering free paths affect the prediction of thermal conductivity for thin films, nanowires, and porous nanofilms. Using Monte Carlo sampling, the effective mean free path for each phonon mode is calculated using a Poisson distribution for the phonon-phonon free path and assuming an equal probability of the phonon originating at any point in the nanostructure. We find our predictions to be consistent with an analytical result for the in-plane direction in the thin films, as opposed to the Matthiessen rule, which leads to an under-prediction by up to 10%. Furthermore, we are able to use our approach to predict the thermal conductivities of complex nanostructures, where correct application of the Matthiessen rule is challenging.
- Heat Transfer Division
Effect of Phonon Free Path Distributions on Nanostructure Thermal Conductivity
Jain, A, & McGaughey, AJH. "Effect of Phonon Free Path Distributions on Nanostructure Thermal Conductivity." Proceedings of the ASME 2012 Heat Transfer Summer Conference collocated with the ASME 2012 Fluids Engineering Division Summer Meeting and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. Volume 1: Heat Transfer in Energy Systems; Theory and Fundamental Research; Aerospace Heat Transfer; Gas Turbine Heat Transfer; Transport Phenomena in Materials Processing and Manufacturing; Heat and Mass Transfer in Biotechnology; Environmental Heat Transfer; Visualization of Heat Transfer; Education and Future Directions in Heat Transfer. Rio Grande, Puerto Rico, USA. July 8–12, 2012. pp. 601-607. ASME. https://doi.org/10.1115/HT2012-58445
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