Dr. Pinar Menguc
Department of Mechanical Engineering
University of Kentucky
Lexington, KY 40506-0503
Phone: 859-257-6336 ext 80658
E-mail: menguc@engr.uky.edu
Enhancement of radiative heat transfer between surface/bodies spaced by a nanometric gap is due to the tunnelling of evanescent waves. Indeed, these evanescent waves, which carry no energy on the average, are always present at the surface of any body at temperature T and extend over a distance of about few nanometers. In far-field radiative heat transfer (classical theory of radiation), these waves have no contribution on the overall radiant energy exchanges. On the other hand, when the surfaces/bodies are spaced close enough (order of nanometer), these evanescent can propagate from one medium to another, and this phenomenon is called radiation tunnelling. Therefore, it must be understood that radiation tunnelling in nanostructures is a new channel in which radiant energy can flow, which is not available in the far-field.
mehanna@engr.uky.edu