THE INFLUENCE OF THE STEFAN NUMBER ON THE FUSION PROCESS UNDER HARMONIC CHANGES OF THE DRIVING TEMPERATURE

The influence of the Stefan number on the one-dimensional fusion proce ss caused by harmonic changes of the air temperature has been investig ated. Analytical relations for zero and infinite Stefan number are com pared with numerical results for an arbitrary Stefan number. A compari son of the variations of the interface location, surface temperature a nd surface heat flux has been accomplished using new general expressio ns for the dimensionless interface location, surface heat flux and Fou rier number. A new analytical relation is proposed, describing the mov ement of the interface for an arbitrary Stefan number and a harmonical ly changing surface temperature. Cases with identical thermal properti es and different thermal parameters in the two phases have been consid ered. An average driving temperature is defined, which gives the same penetration depth in the liquid and solid phase. This is expressed as a function of the thermal properties of the two phases.