We develop a computational framework, based on the Boltzmann transport equation (BTE), with the ability to compute thermal transport in nanostructured materials of any geometry using, as the only input, the bulk cumulative thermal conductivity. The main advantage of our method is twofold. First, while the scattering times and dispersion curves are unknown for most materials, the phonon mean free path (MFP) distribution can be directly obtained by experiments. As a consequence, a wider range of materials can be simulated than with the frequency-dependent (FD) approach. Second, when the MFP distribution is available from theoretical models, our approach allows one to include easily the material dispersion in the calculations without discretizing the phonon frequencies for all polarizations thereby reducing considerably computational effort. Furthermore, after deriving the ballistic and diffusive limits of our model, we develop a multiscale method that couples phonon transport across different scales, enabling efficient simulations of materials with wide phonon MFP distributions length. After validating our model against the FD approach, we apply the method to porous silicon membranes and find good agreement with experiments on mesoscale pores. By enabling the investigation of thermal transport in unexplored nanostructured materials, our method has the potential to advance high-efficiency thermoelectric devices.
Heat Conduction in Nanostructured Materials Predicted by Phonon Bulk Mean Free Path Distribution
Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received August 29, 2014; final manuscript received January 27, 2015; published online March 24, 2015. Assoc. Editor: Robert D. Tzou.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Romano, G., and Grossman, J. C. (July 1, 2015). "Heat Conduction in Nanostructured Materials Predicted by Phonon Bulk Mean Free Path Distribution." ASME. J. Heat Transfer. July 2015; 137(7): 071302. https://doi.org/10.1115/1.4029775
Download citation file:
- Ris (Zotero)
- Reference Manager