Share

Heat Transfer in Graphene and Anisotropic/Nonlinear Systems

2014
Download Heat Transfer in Graphene and Anisotropic/Nonlinear Systems PDF Online Free

Author :
Release : 2014
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Heat Transfer in Graphene and Anisotropic/Nonlinear Systems by : Zhen Chen

Download or read book Heat Transfer in Graphene and Anisotropic/Nonlinear Systems written by Zhen Chen. This book was released on 2014. Available in PDF, EPUB and Kindle. Book excerpt: Various modern devices involve highly anisotropic materials. For example, Bi2Te3 is used in thermoelectrics, and graphene finds broad applications ranging from microelectronics to optoelectronics. The heat transfer in these materials can deviate significantly from classical isotropic transport theory. Nonlinear thermal devices have also drawn a great deal of attention for such applications as thermal regulation of building envelopes, and thermal protection of delicate components in electrical hardware, spacecraft thermal shielding, and satellite radiators. In this thesis, heat transfer in nonlinear devices and anisotropic materials, in particular graphene, is investigated using both experimental and theoretical methods. Measurements on graphene sheets encased by silicon dioxide layers show the strong effect of the encasing oxide in disrupting the thermal conductivity of adjacent graphene layers, leading to more than one order of magnitude suppression as compared to the freely-suspended graphene experiment reported in literature. Modeling thermal properties of anisotropic materials reveals an unexpected guideline to engineer heat transport: due to phonon focusing effects, in many cases the heat transfer can be enhanced by reducing a phonon velocity component perpendicular to the transport direction. Finally, a nonlinear thermal diode, based on a new mechanism exploiting asymmetric scattering of ballistic energy carriers by pyramidal reflectors, is demonstrated experimentally. Experiments underline that all thermal rectifiers require nonlinearity in addition to asymmetry.

Dynamical Analysis of Non-Fourier Heat Conduction and Its Application in Nanosystems

2015-10-14 Science
Download Dynamical Analysis of Non-Fourier Heat Conduction and Its Application in Nanosystems PDF Online Free

Author :
Release : 2015-10-14
Genre : Science
Kind : eBook
Book Rating : 854/5 ( reviews)

GET EBOOK


Book Synopsis Dynamical Analysis of Non-Fourier Heat Conduction and Its Application in Nanosystems by : Yuan Dong

Download or read book Dynamical Analysis of Non-Fourier Heat Conduction and Its Application in Nanosystems written by Yuan Dong. This book was released on 2015-10-14. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies the general heat conduction law, irreversible thermodynamics and the size effect of thermal conductivity exhibited in nanosystems from the perspective of recently developed thermomass theory. The derivation bridges the microscopic phonon Boltzmann equation and macroscopic continuum mechanics. Key concepts such as entropy production, temperature and the Onsager reciprocal relation are revisited in the case of non-Fourier heat conduction. Lastly, useful expressions are extracted from the picture of phonon gas dynamics and are used to successfully predict effective thermal conductivity in nanosystems.

Thermoelectricity and Heat Transport in Graphene and Other 2D Nanomaterials

2017-07-15 Science
Download Thermoelectricity and Heat Transport in Graphene and Other 2D Nanomaterials PDF Online Free

Author :
Release : 2017-07-15
Genre : Science
Kind : eBook
Book Rating : 903/5 ( reviews)

GET EBOOK


Book Synopsis Thermoelectricity and Heat Transport in Graphene and Other 2D Nanomaterials by : Serhii Shafraniuk

Download or read book Thermoelectricity and Heat Transport in Graphene and Other 2D Nanomaterials written by Serhii Shafraniuk. This book was released on 2017-07-15. Available in PDF, EPUB and Kindle. Book excerpt: Thermoelectricity and Heat Transport in Graphene and Other 2D Nanomaterials describes thermoelectric phenomena and thermal transport in graphene and other 2-dimentional nanomaterials and devices. Graphene, which is an example of an atomic monolayered material, has become the most important growth area in materials science research, stimulating an interest in other atomic monolayeric materials. The book analyses flow management, measurement of the local temperature at the nanoscale level and thermoelectric transducers, with reference to both graphene and other 2D nanomaterials. The book covers in detail the mechanisms of thermoelectricity, thermal transport, interface phenomena, quantum dots, non-equilibrium states, scattering and dissipation, as well as coherent transport in low-dimensional junctions in graphene and its allotropes, transition metal dichalcogenides and boron nitride. This book aims to show readers how to improve thermoelectric transducer efficiency in graphene and other nanomaterials. The book describes basic ingredients of such activity, allowing readers to gain a greater understanding of fundamental issues related to the heat transport and the thermoelectric phenomena of nanomaterials. It contains a thorough analysis and comparison between theory and experiments, complemented with a variety of practical examples. Shows readers how to improve the efficiency of heat transfer in graphene and other nanomaterials with analysis of different methodologies Includes fundamental information on the thermoelectric properties of graphene and other atomic monolayers, providing a valuable reference source for materials scientists and engineers Covers the important models of thermoelectric phenomena and thermal transport in the 2D nanomaterials and nanodevices, allowing readers to gain a greater understanding of the factors behind the efficiency of heat transport in a variety of nanomaterials

Thermal Radiative Properties of Uniaxial Anisotropic Materials and Their Manipulations

2020-10-27 Science
Download Thermal Radiative Properties of Uniaxial Anisotropic Materials and Their Manipulations PDF Online Free

Author :
Release : 2020-10-27
Genre : Science
Kind : eBook
Book Rating : 230/5 ( reviews)

GET EBOOK


Book Synopsis Thermal Radiative Properties of Uniaxial Anisotropic Materials and Their Manipulations by : Xiaohu Wu

Download or read book Thermal Radiative Properties of Uniaxial Anisotropic Materials and Their Manipulations written by Xiaohu Wu. This book was released on 2020-10-27. Available in PDF, EPUB and Kindle. Book excerpt: This book presents mainly studies on the calculation methods of thermal radiative properties of uniaxial anisotropic materials, unidirectional transmission, ultrabroadband perfect absorption, and near-field radiative heat transfer with uniaxial anisotropic materials. The results obtained in this book can not only deepen our understanding of the thermal radiative properties of anisotropic materials, but also have important theoretical guiding significance in energy conversion, energy-saving technology, and design of novel devices.

Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains

2015
Download Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains PDF Online Free

Author :
Release : 2015
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains by :

Download or read book Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains written by . This book was released on 2015. Available in PDF, EPUB and Kindle. Book excerpt: High basal plane thermal conductivity k of multi-layer graphene makes it promising for thermal management applications. Here we examine the effects of tensile strain on thermal transport in this system. Using a first principles Boltzmann-Peierls equation for phonon transport approach, we calculate the room-temperature in-plane lattice k of multi-layer graphene (up to four layers) and graphite under different isotropic tensile strains. The calculated in-plane k of graphite, finite mono-layer graphene and 3-layer graphene agree well with previous experiments. The dimensional transitions of the intrinsic k and the extent of the diffusive transport regime from mono-layer graphene to graphite are presented. We find a peak enhancement of intrinsic k for multi-layer graphene and graphite with increasing strain and the largest enhancement amplitude is about 40%. In contrast the calculated intrinsic k with tensile strain decreases for diamond and diverges for graphene, we show that the competition between the decreased mode heat capacities and the increased lifetimes of flexural phonons with increasing strain contribute to this k behavior. Similar k behavior is observed for 2-layer hexagonal boron nitride systems, suggesting that it is an inherent thermal transport property in multi-layer systems assembled of purely two dimensional atomic layers. This study provides insights into engineering k of multi-layer graphene and boron nitride by strain and into the nature of thermal transport in quasi-two-dimensional and highly anisotropic systems.

You may also like...