  Thermal contact has always been a hot issue in many engineering fields and
thermal contact resistance (TCR) is one of the important indicators weighing
the heat transfer efficiency among the interfaces. In this paper, the contact
heat transfer of conforming rough surfaces is theoretically re-estimated
considering both the heat transfer from contact and non-contact regions. The
fluctuational electrodynamics (an ab initio calculation) is adopted to
calculate the thermal radiation. The contribution of contact regions is
estimated by the CMY TCR model and further studied by modelling specific
surfaces with corresponding surface roughness power spectrum (PSD). Several
tests are presented where aluminum and amorphous alumina are mainly used in the
simulations. Studies showed that there exists a significant synergy between the
thermal conduction and near-field thermal radiation at the interface in a
certain range of effective roughness. When the effective roughness is near to
the scales of submicron, the near-field radiation effect should not be
neglected even at room temperature.
