Thermal contact conductance as a method of rectification in bulk materials

Journal Article · Mon Aug 01 00:00:00 EDT 2016 · Heat Transfer Research

DOI:https://doi.org/10.1615/HeatTransRes.2016010297· OSTI ID:1117444

Sayer, Robert A. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

A thermal rectifier that utilizes thermal expansion to directionally control interfacial conductance between two contacting surfaces is presented. The device consists of two thermal reservoirs contacting a beam with one rough and one smooth end. When the temperature of reservoir in contact with the smooth surface is raised, a similar temperature rise will occur in the beam, causing it to expand, thus increasing the contact pressure at the rough interface and reducing the interfacial contact resistance. However, if the temperature of the reservoir in contact with the rough interface is raised, the large contact resistance will prevent a similar temperature rise in the beam. As a result, the contact pressure will be marginally affected and the contact resistance will not change appreciably. Owing to the decreased contact resistance of the first scenario compared to the second, thermal rectification occurs. A parametric analysis is used to determine optimal device parameters including surface roughness, contact pressure, and device length. Modeling predicts that rectification factors greater than 2 are possible at thermal biases as small as 3 K. Lastly, thin surface coatings are discussed as a method to control the temperature bias at which maximum rectification occurs.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1117444
• Report Number(s): SAND--2013-9506J; 481048
• Journal Information: Heat Transfer Research, Journal Name: Heat Transfer Research Journal Issue: 8 Vol. 47; ISSN 1064-2285
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
thermal contact conductance
thermal contact resistance
thermal rectification