Hi, Say I have a sphere of radius r that has a constant surface temperature of T_s. The sphere is surrounded by air at a constant temperature T_amb. I am interested in the temperature gradient surrounding the sphere. From the little I know, I think i have to look at the natural convection and radiation. I can calculate the heat transfer by using newtons cooling law and the law for radiation, but I do not know how to calculate the temperature gradient. Could someone please point me in the right direction? Much appreciated!