Melting of a pure metal on a vertical wall: Numerical simulation

Melting of pure gallium in a bidimensional rectangular cavity with aspect ratio 1.4 is presented. The paper is focused on pattern formation in the fluid phase during the process of melting. The formation of a multiple cells structure has been found during the first stage of the transient, while a merging of the small recirculating cells into larger ones is observed during the following stage of the transient, generating a quite complex evolution of the flow pattern. To ensure the validity of the flow pattern evolution found, a deep mesh sensitivity analysis has been performed and repeated during the different phases of flow evolution. Three different meshes have been tested, the finest of those, assuming asunity the shorter vertical dimension, with a Dx=1/640 and a Dy=1/320. To optimize computational resources requests, an optimal solution strategy has been adopted, using different meshes during the various phases of the transient, depending on the size of the melted zone. Because of the large request of CPU time only one test case is presented and compared with available results at Ra=7x10^5, Pr=0.0216, and Ste=4.6x10^-2. Results show that only the use of a fine mesh allows the observation of the multicellular flowstructure described.