Nanoscale Heat Transfer Due to Near Field Radiation and Nanofluidic Flows

2015 ◽  
Author(s):  
Peter Taborek
Keyword(s):  
Heat Transfer ◽  
Near Field ◽  
Nanoscale Heat Transfer ◽  
Field Radiation

A Numerical Study of the Nanoscale Heat Transfer in the Head-Disk Interface for Heat Assisted Magnetic Recording

2016 ◽  
Author(s):  
Haoyu Wu ◽  
David Bogy
Keyword(s):  
Heat Transfer ◽  
Magnetic Recording ◽  
Transfer Problem ◽  
Numerical Study ◽  
Near Field ◽  
Experimental Result ◽  
Head Disk Interface ◽  
Heat Assisted Magnetic Recording ◽  
Disk Interface ◽  
Nanoscale Heat Transfer

The near field transducer (NFT) overheating problem is an issue the hard disk drive (HDD) industry has faced since heat-assisted magnetic recording (HAMR) technology was first introduced. In this paper, a numerical study of the head disk interface (HDI) is performed to predict the significance of the nanoscale heat transfer due to the back heating from the disk. A steady-state heat transfer problem is first solved to get the disk temperature profile. Then an iterative simulation of the entire HDI system is performed. It shows that the heat transfer coefficient in the HDI increases to about 6:49 × 106 W/(m2K) when the clearance is 0:83 nm. It also shows that in the free space laser scenario, the simulation result is close to the experimental result.

Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the Heat Transfer

2012 ◽  
Author(s):  
X. Zhang ◽  
Z. Y. Guo
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Near Field ◽  
Mean Free Path ◽  
Viscous Force ◽  
Inertia Force ◽  
Relative Importance ◽  
Interfacial Effects ◽  
Nanoscale Heat Transfer ◽  
The Continuum

This paper describes the effects of size on heat conduction in nanofilms, convective heat transfer in micro/nanochannels, and near-field radiation in nanogaps. As the size is reduced, the ratio of the surface area to the volume increases; therefore, the relative importance of the interfacial effects also increases. The physical mechanisms for these size effects have been classified into two classes. When the scale is reduced to the order of micrometers (except for gases), the interfaces only affect the macro parameters and the continuum assumption still holds, but the relative importance of the various forces (inertia force, viscous force, buoyancy, etc.) and effects (interfacial effect, axial heat conduction in the tube wall, etc.) changes, resulting in changes in the heat transfer characteristics from normal conditions. As the size is further reduced to the order of submicrometers or nanometers, the interface affects not only the macro parameters but also the micro parameters (mean free path, relaxation time, etc.) so the continuum assumption breaks down and Newton’s viscosity law and Fourier’s heat conduction law are no longer applicable. Thus, the major characteristic of micro/nanoscale heat transfer is that the interfacial effects dominate the heat transfer.

Thermal transport across a pair of thin silicon films with the presence of minute vacuum gap: effect of film thickness on thermal characteristics

2016 ◽  
Vol 94 (9) ◽  
pp. 933-944 ◽  
Author(s):  
Haider Ali ◽  
Bekir Sami Yilbas
Keyword(s):  
Heat Transfer ◽  
Film Thickness ◽  
Energy Transport ◽  
Near Field ◽  
Radiation Heat Transfer ◽  
Silicon Films ◽  
Radiation Heat ◽  
Field Radiation ◽  
Thin Silicon ◽  
Vacuum Gap

Energy transport across a pair of thin silicon films with the vacuum gap at the films interface is studied. The Boltzmann transport equation is incorporated in the analysis and the solution for the transient frequency-dependent phonon distribution across the films pair is presented. To assess the phonon characteristics, equivalent equilibrium temperature is introduced, which resembles the average energy of all phonons around a local point when they redistribute adiabatically to an equilibrium state. Because the gap size is comparable to the mean free path of silicon, a near-field radiation heat transfer is incorporated across the film edges at the interface. The frequency cutoff method is used at the interface of the films and the phonons jump across the gap resembling the ballistic phonon contribution to the energy transport is accommodated. The thermal conductivity data predicted are validated with the data obtained from the previous study. The effect of near-field radiation heat transfer on temperature increase at the edges of the film, across the gap interface, is not considerable as compared to that corresponding to phonons transmitted across the gap. Increasing the first film thickness increases temperature difference across the gap, which is more pronounced for large gap sizes.

scholarly journals Heat transfer statistics in extreme-near-field radiation

2018 ◽  
Vol 98 (12) ◽  
Author(s):  
Gaomin Tang ◽  
Jian-Sheng Wang
Keyword(s):  
Heat Transfer ◽  
Near Field ◽  
Field Radiation

Thermotunneling Systems for Advanced Efficient Cooling

2009 ◽  
Author(s):  
Mehmet Arik ◽  
Stanton Weaver ◽  
James W. Bray
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Near Field ◽  
Radiation Heat Transfer ◽  
The Other ◽  
Junction Temperature ◽  
Thermodynamic Efficiency ◽  
Dual Use ◽  
Radiation Heat ◽  
Field Radiation

Refrigeration for electronics components has been studied to keep the junction temperature below allowable limits. Thermoelectrics have been investigated heavily for their dual use over the last six decades These devices can be used for both cooling and power generation. Thermotunneling devices, on the other hand, have been known only for the last two decades, and nobody has been able to manufacture or show the performance of those devices. In this study, we will discuss the thermodynamic efficiency of these systems and design bottlenecks to reach high efficiencies, such as thermal back path and electrical losses. Concepts for possible device designs will be discussed. Then attention will be turned to near field radiation heat transfer that becomes critical in nano scale device designs.

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