EXPERIMENTAL STUDIES OF RADIATIVE HEAT TRANSFER BETWEEN BODIES AT SMALL SEPARATIONS

Abstract

Radiative heat transfer between bodies can be significantly enhanced beyond Planck’s law in the near field due to photon tunneling. Extensive theoretical work was reported to study near-field radiation between bodies with different geometries and materials. Although experimentally measuring heat transfer at small gaps is very difficult, many advanced experimental techniques have been developed to measure near-field radiative heat transfer over the past decades. The aim of this chapter is to give an in-depth review about those experimental techniques, measured results, and their comparison with theoretical predictions. The previous experimental studies are categorized in terms of three configurations: parallel-plate, tip-plate, and sphere-plate. Future directions of measuring near-field radiation are also discussed.