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Baokun Liu

Publications and source records attributed to Baokun Liu.

2 recordsLinked to original sources

Many-body interaction on near-field radiative heat transfer between two nanoparticles caused by proximate particle ensembles

Near-field radiative heat transfer (NFRHT) has received growing attention because of its high intensity far beyond the Planck's black-body limit. Insertion of a third object in proximity of the two articles can significantly influence and manipulate its NFRHT. However, for the system composed of many particles, the effect of many-body interaction (MBI) on NFRHT between arbitrary two particles is still not well understood. In this work, the MBI is studied for two particles with three typical proximate ensembles: particle chain, plane and grating. With the increasing of proximate particle size, the MBI on NFRHT will experience a radical change from inhibition to enhancement. The polarizability of the proximate particle increases with particle radius, which enhances the interaction between the proximate particles and the main particle, and then results in enhancement of NFRHT between the main particles. When twisting the proximate particle ensemble, the proximate MBI accounts for a smooth and non-oscillated twisting angle dependence of NFRHT, different from the oscillation phenomenon of NFRHT for particle gratings. This work deepens the understanding of NFRHT in dense particulate systems.

physics.optics

Continuum approach based on radiation distribution function for radiative heat transfer in densely packed particulate system

The study of radiative heat transfer in particulate system is usually based on radiative transfer equation (RTE) with effective radiative properties. However, for non-random, densely and regularly packed particulate systems, the applicability of RTE is questionable due to dependent scattering and weak randomness of particle arrangement. In this paper, a new continuum approach that does not explicitly rely on the RTE is proposed for radiative heat transfer in the densely packed particulate system. The new approach is based on the generalization of the concept of radiation distribution factor (RD) at discrete scale (or particle scale) to radiation distribution function (RDF) at continuum scale. The derived governing equation is in integral form, with RDF as the continuum scale physical parameter that characterize the radiative transfer properties of the system. The characteristics of the RDF for different particulate system (randomly or regularly packed) are studied. The RDF in regularly distributed particulate system is shown to be anisotropic. The continuum approach is verified by using heat transfer simulation at the particle scale, and demonstrated to have excellent performance in predicting the temperature distribution in dense particulate system. This work provides an alternative continuum theory, which will help the analysis and understanding of radiative heat transfer in densely packed media.

physics.app-ph