Solidification and Melting of Aluminum onto Circular Cylinders Under Forced Convection: Experimental Measurements and Numerical Modeling

The solid-liquid interface is examined as aluminum solidifies and melts onto a circular cylinder in flowing liquid aluminum. Cylinders of different elemental composition from aluminum were immersed into liquid aluminum flow-fields under conditions which promote the aluminum solid-liquid interface to move forward and then in reverse. The solidification and melting time (SMT) of the aluminum shell was measured by thermocouples located on the surface of the cylinder. These thermocouples monitor the point in time where the receding solid-liquid interface approaches the surface of the cylinder. The data demonstrate that the shell solidifies and melts faster closer to the stagnation point. ANSYS Fluent, which incorporates an enthalpy algorithm, was utilized to predict this phase change process. When a thermal resistance is implemented at the cylinder-aluminum interface, there is good agreement between the numerically predicted and the experimentally measured aluminum shell SMTs. The effect of various magnitudes of thermal resistance at the cylinder-aluminum interface was explored on the local aluminum SMTs.