Simplified model of transient radiative cooling of spherical body

The cooling of a spherical body in case when radiation is the only heat transfer mechanism between the body surface and the environment has been considered. A mathematical process model employing an own approximate kinetic equation of heat conduction has been worked out. Thus, the process has been described by an ordinary differential equation combined with an algebraic one. The proposed simplified model has been compared with the exact solution and with approximate relations presented by Su [4]. It has been found that the proposed model is accurate and employable for both long and short times as well as for any relations between outer and inner heat transfer resistances.