3-DIMENSIONAL TRANSIENT HEAT-TRANSFER FROM A BURIED PIPE .3. COMPREHENSIVE MODEL

The transient heat transfer problem of solidification of a liquid Rowi ng in a buried pipe is analyzed. The system is cooled from a horizonta l Rat top surface. The model described in the preceding two manuscript s in this series has been extended to the case when a fluid in laminar flow inside a buried pipe freezes. The cross section for flow, which changes with axial position and time, has been approximated as an elli pse. The velocity profile, which is required in the partial differenti al equation for the temperature inside the Rowing fluid, is determined from the dimensions of the ellipse. Numerical procedures are presente d For tracking the moving interface between the solid and the fluid in laminar flow. Simulation examples demonstrate the impact of the Reyno lds number on the times to freezing, the temperature profiles and the thickness of the ice layers formed. The effects of pipe burial depth a nd of other parameters in the model are also examined.