Modeling and simulation of alloys solidification and prediction of segregations

This internship falls within a R&D project of Electricité de France which focus on the comprehen- sion of the causes and the consequences of the positive segregations localized in some identified components of the French nuclear plants. During ingot castings, a non uniform distribution of the alloy components can be observed. These heterogeneities at the ingot scale, called macrosegrega- tions, can impact the mechanical characteristics of the material and in some cases they weaken its resistance to cracks. In order to progress on the identification and the comprehension of the main mechanisms leading to macrosegregations, the internship focused on the implementation of a simple solidification model in Code_Saturne the CFD open-source code developed at EDF. This work include sensibility studies upon the physical model and upon the numerical methods of a strongly coupled equations system. The proposed model has been simulated on academic and industrial cases and compared to other models and to some experimental data.

Questo stage è stato proposto da Electricité de France Ricerca & Sviluppo e si concentra sulla comprensione delle cause e delle conseguenze delle segregazione positive trovate su alcuni componenti delle centrale nucleare francese. Un semplice modello di solidificazione è stato implementato in Code_Saturne. Questa tesi comporta delle analisi di sensibilita per quanto riguarda il modello fisico e i metodi numerici. Alla fine il codice è stato verificato con dei benchmarks e dati sperimentali