The Convection of Heat from Small Copper Wires

Abstract

It is well known that when an electrically heated wire is supported in air, it dissipates its heat by conduction, radiation and convection. Conduction takes place longitudinally through and into the metallic terminals of the wire, and would take place laterally through the air, if the latter were kept at rest like a rigid medium. The metallic conduction at the ends may be eliminated by confining observation to parts of the wire not near the ends. The lateral conduction through the air is also negligible, because the air does not remain at rest but expands and flows convectively. Consequently we may safely ignore conductive thermal loss.