Transient Heat Transfer Through a Thin Circular Pipe Due to Unsteady Flow in the Pipe

An analysis of the transient heat transfer between a thin circular tube and the incompressible fluid moving through the tube is made for the case where the temperature of the inlet fluid is kept constant. Both radial conduction of heat in the wall and the heat loss at the outer surface of the cylinder are taken into consideration. It is shown to be especially easy to calculate temperature of both fluid and tube in the initial period by means of the figures. So far, it is common to use the temperature of the wall calculated by the assumption that it is constant radially. It is shown that for the insulated tube in the initial period such temperature is equal to the temperature of the outer surface of the tube. The temperature of the inner surface of the tube may be appreciably different from such temperature even for the metallic tube. The difference is extremely large for the tube made from insulating material.