Modeling of Constriction Resistance in Coated Joints

Metallic coatings applied to surfaces in contact have been shown to be effective at reducing thermal contact resistance. Contact resistance is primarily caused by the constriction of heat flow as it passes through individual contact spots. Most analyses of coated constrictions have been limited to plane contacts of a semi-infinite cylinder, whereas an actual constriction terminates in a shape like the frustum of a cone. A numerical model has been developed to determine the constriction resistance of such a coated asperity. The gap between the cone and contact surface is considered either to be evacuated or filled with a gas, and the temperature jump phenomenon is included in the gas-gap model. The effects of radiation heat transfer are also included