Electrically and frictionally derived mound temperatures in carbongraphite brushes

摘要

Numerical and analytical simulations of mound temperatures arepresented as the mound evolves from cold to hot. The temperature fieldabout a thermal mound in an electrical brush is estimated using a heatconduction equation with frictional and electrical internal heatsources. Computed temperatures seem to agree with measured temperatures,but thermal nonlinearities can result in temperatures that are higherand hot zones that are larger than the mathematical sum of thefrictional and joule thermal fields. It is found that combined heatingcoupled with nonlinear effects can significantly shorten the formationtime of very hot temperature zones. Computed thermal fields maturewithin about 4 ms, the approximate lifetime of a stationary mound on thebrush face. This suggests validity for the assumption that the mound isstationary on the brush during thermal evolution