Overview Describes the physical background and some of the nomenclature. Lumped Analysis Transient solution for a highly conductive or small radius sphere. Transient with Radial Temperature Variation Transient solution when the radial temperature gradient is important. Overview The remainder of this page deals with the physical experiment depicted in the sketch below. A sphere of uniform material is intially at some temperature T h .
T h washes over the sphere.
The moving fluid provides convective cooling of the sphere. The thermophysical properties of the sphere and the effectiveness of the convective cooling determine the internal temperature distribution of the sphere as it cools. In other words there will be little difference in temperature between the surface and the center of the sphere. On the other hand if the material has a low conductivity and if the convective cooling is strong then the internal temperature of the sphere will not be uniform. This is the case qualitatively represented by the color distribution in the sphere on the right hand side of the preceding sketch.