To elucidate the three-way relationship among a crystal’s structure, its phonon dispersion characteristics, and its thermal conductivity, an analysis is conducted on layered diatomic Lennard-Jones crystals with various mass ratios. Lattice dynamics theory and molecular dynamics simulations are used to predict the phonon dispersion curves and the thermal conductivity. The layered structure gener...

In this paper, finite element method is used to obtain thermal conductivity coefficients of single-walled carbon nanotube reinforced polypropylene. For this purpose, the two-dimensional representative volume elements are modeled. The effect of different parameters such as nanotube dispersion pattern, nanotube volume percentage in polymer matrix, interphase thickness between nanotube and surroun...

his investigation was carried out to reveal the impact of solar radiation on wind flow structure and pollutant dispersion in an urban street canyon of aspect ratio of one using the computational fluid dynamic (cfd) technique. the simulation results (velocity and concentration data) show that heating from building wall surfaces and ground lead to strong buoyancy forces as the air is heated by th...

In this paper, analysis for the propagation of general anisotropic media of finite thickness with two thermal relaxation times is studied. Expression of displacements, temperature, thermal stresses, and thermal gradient for most general anisotropic thermoelastic plates of finite thickness are obtained in the analysis. The calculation is then carried forward for slightly more specialized case of...

The thermal properties of Si nanowires (NWs) are of high interest for a variety of applications such as thermal management and thermoelectricity. Most simulation studies to date use the Si bulk dispersion within a confined geometry. The phonon dispersion in ultra-narrow 1D NWs, however, is different from the bulk dispersion, and can lead to different thermal properties. In this work, we study t...

Photothermal techniques are based on the thermal waves detection, such waves are generated when a modulated light strikes on a sample material, thermal waves then travel through the material, is the material is homogenous then thermal waves propagate freely and, only suffering an attenuation as a function of traveled distance, when the material has defects the waves will suffer not only attenua...

Photothermal techniques are based on the thermal waves detection, such waves are generated when a modulated light strikes on a sample material, thermal waves then travel through the material, is the material is homogenous then thermal waves propagate freely and, only suffering an attenuation as a function of traveled distance, when the material has defects the waves will suffer not only attenua...

The theory accounting for nonlinear particle relaxation (viscous and thermal) has been applied to the prediction of dispersion of sound in dilute suspensions. The results suggest that significant deviations exist for sound dispersion between the linear and nonlinear theories at large values of omegatau(d), where omega is the circular frequency and tau(d) is the Stokesian particle relaxation tim...

The phononic band structure and thermal conductivity of a family of a two-atom unit cell Lennard-Jones crystals are predicted using molecular dynamics simulations. The structure consists of alternating layers of atoms with different masses, leading to anisotropic thermal properties. An increase in the mass ratio results in an increase in the width of the band gap and a decrease in the value of ...