Evaluations of Thermal Contact Resistance in an Atmospheric Environment.

Abstract

To accurately analyze temperature field and thermal stress problem with contact surface, the effects of thermal resistance of contact surface must be taken into consideration. Most studies on thermal contact resistance problem have been carried out for especially such critical structures as space equipment and nuclear plant, and the others were devoted to some special contact conditions whose contact pressure was less then 5MPa. In this paper, thermal contact resistance is measured with an infrared thermography system for contact surfaces composed of common structural members, where the contact pressure and surface roughness are varied over a wide range. In addition, an empirical equation is proposed to evaluate the thermal contact coefficient for common engineering materials in an atmospheric environment. As an application of engineering problem, a contact temperature field in a bolted joint is analyzed using finite element method as a heat transfer problem with contact surface, and the validity of the empirical equation proposed here is ascertained by comparing with experimental results.