Perfect thermal contact
Perfect thermal contact of the surface of a solid with the environment (convective heat transfer) or another solid occurs when the temperatures of the mating surfaces are equal. == Perfect thermal contact conditions == Perfect thermal contact supposes that on the boundary surface A {\displaystyle A} there holds an equality of the temperatures T | A = T e | A {\displaystyle T{\big |}_{A}=T_{e}{\big |}_{A}\,} and an equality of heat fluxes − k ∂ T ∂ n | A = − k e ∂ T e ∂ n | A {\displaystyle -k{\frac {\partial T}{\partial n}}{\bigg |}_{A}=-k_{e}{\frac {\partial T_{e}}{\partial n}}{\bigg |}_{A}\,} where T , T e {\displaystyle T,~T_{e}} are temperatures of the solid and environment (or mating solid), respectively; k , k e {\displaystyle k,~k_{e}} are thermal conductivity coefficients of the solid and mating laminar layer (or solid), respectively; n {\displaystyle n} is normal to the surface A {\displaystyle A} .