THERMAL MODELING OF STEADY-STATE CONTACT RESISTANCE BETWEEN 2 DISSIMILAR MATERIALS

Contact resistance between two dissimilar materials of finite thicknes s is formulated as two cylinders in contact over a small area at their centers with their lateral surfaces insulated while the top and botto m surfaces are kept at constant temperatures. Heat diffusion equations in the cylinders are transformed to an integral equation for the heat flux through the contact area. The integral equation is solved numeri cally and no assumption regarding the heat flux distribution on the co ntact surface is made. An expression for the dimensionless contact res istance is developed using the rare of heat transfer through the conta ct area. The effect of the length of the cylinders on contact resistan ce is evaluated. The limiting case of contact resistance for long cyli nders is compared with the solution reported in literature. A correlat ion is developed for the heat flux distribution for long cylinders as a function of dimensionless contact radius. The results are reported i n dimensionless form convenient for parametric study and design analys is. (C) 1998 The Franklin institute. Published by Elsevier Science Ltd .