English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this paper, a finite-volume discrete unified gas kinetic scheme (DUGKS)based on the non-gray phonon transport model is developed for multiscale heattransfer problem with arbitrary temperature difference. Under large temperaturedifference, the phonon Boltzmann transport equation (BTE) is essentiallymultiscale, not only in the frequency space, but also in the spatial space. Inorder to realize the efficient coupling of the multiscale phonon transport, thephonon scattering and advection are coupled together in the present scheme onthe reconstruction of the distribution function at the cell interface. TheNewtonian method is adopted to solve the nonlinear scattering term for theupdate of the temperature at both the cell center and interface. In addition,the energy at the cell center is updated by a macroscopic equation instead oftaking the moment of the distribution function, which enhances the numericalconservation. Numerical results of the cross-plane heat transfer prove that thepresent scheme can describe the multiscale heat transfer phenomena accuratelywith arbitrary temperature difference in a wide range. In the diffusive regime,even if the time step is larger than the relaxation time, the present schemecan capture the transient thermal transport process accurately. Compared tothat under small temperature differences, as the temperature differenceincreases, the variation of the temperature distribution behaves quitedifferently and the average temperature in the domain increases in theballistic regime but decreases in the diffusive regime.

Discrete unified gas kinetic scheme for multiscale heat transfer with arbitrary temperature difference