Geometry for Efficient External and Internal Cooling of Cylindrical Heat Sources

A unique geometry is found for a heat generating cylindrical rod cooled on both sides within a coolant channel, which leads to the same coolant temperature and the same surface temperature on both sides of the rod. The “optimum” rod i.d./o.d. is close to one-half and the corresponding overall void fraction close to 57% for cylindrical, hexagonal, or square channel configurations.