Transient thermal field in cylindrical item and shaft

For easy removal of cylindrical item from the shaft the item is heated on its external surface for thermal expansion. The best result is obtained if the temperature difference between the internal surface of the item and external surface of the shaft is highest. Since the item can be heated only on its external surfaces, in the paper the transient thermal field is analyzed inside the item and the shaft, when a constant high temperature suddenly occurs on the external cylindrical surface of the homogenous item and the best time for item removal is determined. The maximal temperature drop on the air gap is also calculated. An example of application is given.