A diffuse interface method for simulation‐based screening of heat transfer processes with complex geometries

Abstract

Frequently, the simulation‐based design of physicochemical processes requires screening of large numbers of alternative designs with complex geometries. These geometries may result in conformal meshes which introduce stability issues, significant computational complexity, and require user‐interaction for their creation. In this work, a method for simulation of heat transfer using the diffuse interface method to capture a complex geometry is presented as an alternative to conformal meshing, with analysis and comparisons given. The methods presented include automated non‐iterative generation of phase fields from CAD geometries and an extension of the diffuse interface method for mixed boundary conditions. Simple measures of diffuse interface quality are presented and used to predict performance. The method is applied to a realistic three‐dimensional heat transfer problem (LED heat sink) and compared to the traditional conformal mesh approach. It is found to enable reasonable accuracy at an order‐of‐magnitude reduction in simulation time or comparable accuracy for equivalent simulation times.

Diffuse-Interface Blended Method for Imposing Physical Boundaries in Two-Fluid Flows

“…Instead of using a conformal mesh, the physical boundaries may be “embedded” in the problem, which has been a topic of research in the area of single-phase fluid mechanics for several decades, especially for fluid-structure interaction problems. Examples of past relevant work includes the use of the fictitious domain, immersed boundary, − and diffuse domain/interface − methods. Physical boundaries are defined in the embedded domain method through the use of a level-set function, a phase-field, or similar continuous indicator field.…”