Cooperative interactions of asperities in the thermotribology of sliding contacts

Thermal conduction through a stationary cluster of microcontacts is treated by an approximation which shows that thermal resistance of the cluster may be close to that for a region of uniform contact of the same size. The derivation is extended to sliding contacts, where thermal conduction is greatly different from that of stationary contacts. The conclusion is that a uniform contact may be a valid approximation in predicting thermal resistance. This supports the numerical validity of treating conduction through Hertzian contacts as though elastic contact of smooth bodies was involved, with conduction occurring over the full Hertzian patch, irrespective of roughness. It also supports the modeling of quasi-Hertzian contact of thermoelastically formed mounds by smooth-surface models