PhD defense of Cynthia Hayek

Cynthia Hayek will defend her PhD in Computational Mathematics, High Performance Computing and Data on Nov. 24, 23.

Modeling and high-fidelity simulation of the Lost Foam Casting process

Cynthia Hayek conducted her PhD work in the CFL team under the supervision of Elie Hachem and Rudy Valette. She will defend her PhD in Computational Mathematics, High Performance Computing and Data, on November 24th, 23 in front of the following jury:

Abstract:

The Lost Foam Casting process is a form of evaporative-pattern casting selected to manufacture automotive parts, where a polymeric foam pattern, covered by a refractory material permeable to gas and surrounded by sand is replaced by a flowing hot liquid metal. When the pattern enters in direct contact with the metal, it decomposes, forming an intermediate decomposition layer between the metal and the pattern, which evacuates through the refractory material. Modeling such a multi-scale and multi-physical problem lead to undesirable computational cost. In this thesis, we present a fast and user-friendly model suitable for 3D industrial topologies. The advection velocity was derived by coupling multiple phenomena (heat transfer, foam phase change, mass transfer). The model was then refined by addressing scenarios when the vaporizing front is distorted, which occurs when a thin ‘undercut’ layer of vapor is formed near the wall. Additionally, we extended the model to address situations where the metal front advances in a counter-gravity direction. Both the global and local models were solved numerically using our finite element library. Various descriptors were extracted, enabling predictions of potential defect formation locations in the casting process.

Keywords: CFD, Phase Change, Physics of interfaces, Heat Transfer, Porous Media