Micro and Nano Thermal Transport

Micro and Nano Thermal Transport
Author: Lin Qiu
Publisher: Academic Press
Total Pages: 358
Release: 2022-02-09
Genre: Science
ISBN: 012823623X

Download Micro and Nano Thermal Transport Book in PDF, Epub and Kindle

Micro and Nano Thermal Transport Research: Characterization, Measurement and Mechanism is a complete and reliable reference on thermal measurement methods and mechanisms of micro and nanoscale materials. The book has a strong focus on applications and simulation, providing clear guidance on how to measure thermal properties in a systematic way. Sections cover the fundamentals of thermal properties before introducing tools to help readers identify and analyze thermal characteristics of these materials. The thermal transport properties are then further explored by means of simulation which reflect the internal mechanisms used to generate such thermal properties. Readers will gain a clear understanding of thermophysical measurement methods and the representative thermal transport characteristics of micro/nanoscale materials with different structures and are guided through a decision-making process to choose the most effective method to master thermal analysis. The book is particularly suitable for those engaged in the design and development of thermal property measurement instruments, as well as researchers of thermal transport at the micro and nanoscale. Includes a variety of measurement methods and thermal transport characteristics of micro and nanoscale materials under different structures Guides the reader through the decision-making process to ensure the best thermal analysis method is selected for their setting Contains experiments and simulations throughout that help apply understanding to practice

Exploring Heat Transfer at the Atomistic Level for Thermal Energy Conversion and Management

Exploring Heat Transfer at the Atomistic Level for Thermal Energy Conversion and Management
Author: Zhiting Tian
Publisher:
Total Pages: 115
Release: 2014
Genre:
ISBN:

Download Exploring Heat Transfer at the Atomistic Level for Thermal Energy Conversion and Management Book in PDF, Epub and Kindle

Heat transfer at the scales of atoms plays an important role in many applications such as thermoelectric energy conversion and thermal management of microelectronic devices. While nanoengineering offers unique opportunities to manipulate heat to our advantages, it also imposes challenges on the fundamental understanding of nanoscale heat transfer. As the characteristic lengths of the system size become comparable to the mean free paths of heat carriers, macroscopic theories based on heat diffusion are no longer valid due to size effects. Atomistic level simulation can provide powerful insights into the microscopic processes governing heat conduction, and is the focus of this thesis. In this thesis, we first introduce atomistic techniques to investigate phonon transport in bulk crystals. We start with normal mode analysis within the classical molecular dynamics framework to estimate the spectral phonon transport properties. Although it can provide the detailed phonon properties adequately, classical molecular dynamics with empirical potentials do not always yield accurate predictions. Then, we move to first-principles density functional theory (DFT) to compute mode-dependent phonon properties. Such simulations can well reproduce experimental values of phonon dispersion and thermal conductivity with no adjustable parameters, establishing confidence that such an approach can provide reliable information about the microscopic processes. These detailed calculations not only unveil which phonon modes are responsible for heat conduction in bulk crystals, but also expand our fundamental understanding of phonon transport, such as the importance of optical phonons. Next, we study thermal transport across single and multiple interfaces via the atomistic Green's function method, especially the impact of interface roughness on phonon transmission across a single interface and coherent phonon transport in superlattices. Both the DFT and Green's function techniques provide fundamental parameters that then can be used to understand mesoscale transport. This paves the way for multiscale modeling from first-principles. Through these multiscale modeling efforts, we are able to obtain a comprehensive understanding of heat transfer from the atomistic to the macroscale, with important implications for energy applications. Complementary to the theoretical work, we measure the interface thermal conductance using ultrafast time-domain thermoreflectance experiments, examining thermal transport across solid-liquid interfaces modified by self-assembled monolayers. We find that an extra molecular layer can enhance the thermal transport across solid-liquid interfaces. In summary, theoretical, computational and theoretical approaches have been applied to study heat transfer at the atomistic level. The findings from this thesis have improved our fundamental understanding of phonon transport properties with important implications for energy applications and beyond, and build a foundation for multiscale simulation of phonon heat conduction at the mesoscale.

Implications of the Interface Modelling Approach on the Heat Transfer Across Solid-Liquid Interfaces and Thin-Film Evaporation

Implications of the Interface Modelling Approach on the Heat Transfer Across Solid-Liquid Interfaces and Thin-Film Evaporation
Author: Carlos Gonzalez-Valle
Publisher:
Total Pages:
Release: 2021
Genre:
ISBN:

Download Implications of the Interface Modelling Approach on the Heat Transfer Across Solid-Liquid Interfaces and Thin-Film Evaporation Book in PDF, Epub and Kindle

In this Dissertation, the governing mechanisms of thermal energy transfer across solid-liquid interfaces and thin-film evaporation are investigated by means of classical molecular dynamics (MD) simulations. In an effort to steer the heat transfer community from heavily empirical techniques into more physically sound methods, significant attention was given to the formulation physics and chemistry informed interface modelling approaches in MD simulations of heat transfer and evaporation. MD simulations were carried out to characterize and analyze the parameters affecting interfacial heat transport, namely, the solid-liquid affinity, the interfacial vibrational compatibility, and the liquid structuring. Understanding and controlling heat transfer and evaporation is fundamental for various applications, such as photothermal therapy and diagnosis, water desalination, additive manufacturing, energy storage and conversion, and thermal management of high-power electronics. For water desalination, electronics cooling, and nanoparticle-mediated thermotherapy, materials featuring good chemical stability, wide band gap, and biological compatibility are necessary. Therefore, inspired by the current technological interests in solid-liquid interfaces, this Dissertation was dedicated to investigate aqueous interfaces of silicon carbide (SiC) and aluminum oxide (alumina). In addition, graphite-water interfaces were used as a reference framework, since this system has been extensively characterized and studied, and several interfacial modelling parameters are available in the literature. The surface wettability was theoretically and numerically characterized for SiC evaluating the effect of different crystallographic orientations and surface terminations. Anysotropy of wettability was found and analytical models based on Mean-Field theory could adequately describe the wetting behavior for compound materials. In addition, the calculations of the interfacial thermal conductance for SiC showed that the most hydrophilic surfaces were not the most conductive, opposing to the conventional notions that related efficient interfacial thermal transport with hydrophilic surfaces. By including additional parameters, such as the interfacial liquid depletion, a reconciliation of the interfacial thermal conductance was observed, indicating that the surface wettability is only one of the mechanisms involved in the thermal transport phenomena. The potential effect of the liquid structuring on the interfacial thermal transport was verified by the calculation of the thermal conductance at the graphite-water interface. The various interface parameters considered produced a wide spectrum of wetting conditions; nonetheless, no direct relationships between wetting parameters such as the contact angle, the work of adhesion, and the binding energy were observed. Similar to the observed for SiC, the liquid density depletion helped to reconcile the calculations of the interfacial conductance for the graphite-water interface. A more complex interfacial model accounting for surface chemistry and electrostatic interactions was developed to analyze the alumina-water interface. The results indicated that wetting and thin-film evaporation are significantly susceptible to interfacial modeling parameters. Moreover, the improper definition of the atomic interactions led to unphysical droplet spreading when using widely accepted modeling parameters for water-alumina interactions. The characterization of interfacial thermal transport for alumina demonstrated the exitance of an interplay between the solid-liquid affinity, the interfacial vibrational compatibility, and the formation of hydrogen bonds. Thin-film evaporation results showed significant variations in the evaporating film thickness and the evaporation mass fluxes with the different interface models, which demonstrated the crucial role of a robust interfacial modelling approach in capturing evaporation in MD simulations.

Nano-scale Heat Transfer in Nanostructures

Nano-scale Heat Transfer in Nanostructures
Author: Jihong Al-Ghalith
Publisher: Springer
Total Pages: 88
Release: 2018-03-06
Genre: Science
ISBN: 3319738828

Download Nano-scale Heat Transfer in Nanostructures Book in PDF, Epub and Kindle

The book introduces modern atomistic techniques for predicting heat transfer in nanostructures, and discusses the applications of these techniques on three modern topics. The study of heat transport in screw-dislocated nanowires with low thermal conductivity in their bulk form represents the knowledge base needed for engineering thermal transport in advanced thermoelectric and electronic materials, and suggests a new route to lower thermal conductivity that could promote thermoelectricity. The study of high-temperature coating composite materials facilitates the understanding of the role played by composition and structural characterization, which is difficult to approach via experiments. And the understanding of the impact of deformations, such as bending and collapsing on thermal transport along carbon nanotubes, is important as carbon nanotubes, due to their exceptional thermal and mechanical properties, are excellent material candidates in a variety of applications, including thermal interface materials, thermal switches and composite materials.

Nanoscale Energy Transport and Conversion

Nanoscale Energy Transport and Conversion
Author: Gang Chen
Publisher: Oxford University Press
Total Pages: 570
Release: 2005-03-03
Genre: Science
ISBN: 9780199774685

Download Nanoscale Energy Transport and Conversion Book in PDF, Epub and Kindle

This is a graduate level textbook in nanoscale heat transfer and energy conversion that can also be used as a reference for researchers in the developing field of nanoengineering. It provides a comprehensive overview of microscale heat transfer, focusing on thermal energy storage and transport. Chen broadens the readership by incorporating results from related disciplines, from the point of view of thermal energy storage and transport, and presents related topics on the transport of electrons, phonons, photons, and molecules. This book is part of the MIT-Pappalardo Series in Mechanical Engineering.

Final Report

Final Report
Author:
Publisher:
Total Pages: 7
Release: 2006
Genre:
ISBN:

Download Final Report Book in PDF, Epub and Kindle

Research supported by this grant has significantly advanced fundamental understanding of the thermal conductance of solid-liquid interfaces, and the thermal conductivity of nanofluids and nanoscale composite materials. The thermal conductance of interfaces between carbon nanotubes and a surrounding matrix of organic molecules is exceptionally small and this small value of the interface conductance limits the enhancement in thermal conductivity that can be achieved by loading a fluid or a polymer with nanotubes. The thermal conductance of interfaces between metal nanoparticles coated with hydrophilic surfactants and water is relatively high and surprisingly independent of the details of the chemical structure of the surfactant. We extended our experimental methods to enable studies of planar interfaces between surfactant-coated metals and water where the chemical functionalization can be varied between strongly hydrophobic and strongly hydrophilic. The thermal conductance of hydrophobic interfaces establishes an upper-limit of 0.25 nm on the thickness of the vapor-layer that is often proposed to exist at hydrophobic interfaces. Our high-precision measurements of fluid suspensions show that the thermal conductivity of fluids is not significantly enhanced by loading with a small volume fraction of spherical nanoparticles. These experimental results directly contradict some of the anomalous results in the recent literature and also rule-out proposed mechanisms for the enhanced thermal conductivity of nanofluids that are based on modification of the fluid thermal conductivity by the coupling of fluid motion and the Brownian motion of the nanoparticles.

Microscale and Nanoscale Heat Transfer

Microscale and Nanoscale Heat Transfer
Author: Mourad Rebay
Publisher: CRC Press
Total Pages: 499
Release: 2016-01-06
Genre: Science
ISBN: 1498736319

Download Microscale and Nanoscale Heat Transfer Book in PDF, Epub and Kindle

Microscale and Nanoscale Heat Transfer: Analysis, Design, and Applications features contributions from prominent researchers in the field of micro- and nanoscale heat transfer and associated technologies and offers a complete understanding of thermal transport in nano-materials and devices. Nanofluids can be used as working fluids in thermal system

Nanoscale Liquid Interfaces

Nanoscale Liquid Interfaces
Author: Thierry Ondarçuhu
Publisher: CRC Press
Total Pages: 782
Release: 2013-04-17
Genre: Science
ISBN: 9814316458

Download Nanoscale Liquid Interfaces Book in PDF, Epub and Kindle

This book addresses the recent developments in the investigation and manipulation of liquids at the nanoscale. This new field has shown important breakthroughs on the basic understanding of physical mechanisms involving liquid interfaces, which led to applications in nanopatterning. It has also consequences in force microscopy imaging in liquid environment. The book proposes is a timely review of these various aspects. It is co-authored by 25 among the most prominent scientists in the field.

Thermal Transport for Applications in Micro/Nanomachining

Thermal Transport for Applications in Micro/Nanomachining
Author: Basil T. Wong
Publisher: Springer Science & Business Media
Total Pages: 243
Release: 2008-07-19
Genre: Science
ISBN: 3540736077

Download Thermal Transport for Applications in Micro/Nanomachining Book in PDF, Epub and Kindle

Beginning with an overview of nanomachining, this monograph introduces the relevant concepts from solid-state physics, thermodynamics, and lattice structures. It then covers modeling of thermal transport at the nanoscale and details simulations of different processes relevant to nanomachining. The final chapter summarizes the important points and discusses directions for future work to improve the modeling of nanomachining.