Thermal contact resistance is a confounding problem in most thermal engineering problems. Coating of one or both surfaces of a joint has been identified as an effective method of controlling the thermal conductance of the joint. The first step in predicting the contact conductance of a coated joint is to determine the constriction resistance associated with an individual contact spot. Most previous analyses of coated constrictions have been limited toplane contacts of a semiinfinite solid. In reality, the constriction is a bounded finitie volume that terminates in a shape like the frustum of a cone. The present work describes a numerical analysis that takes into account the size of the constriction, the cone semi-angle, the coating thciness, and the coating conductivity. The results indicate that the effect of the coating is most pronounced for smaller constriction ratios; an optimum coating thickness for minimizing the constriction resistance has been found to exist in all cases.
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