Contents
Flow, heat transfer & particle transport in metal foams
Context
Porous media are nowadays common materials in many thermal or mechanical engineering applications such as heat exchangers or oil/air separators. However, since a few decades, a new type of such "macro-porous" media called metal foams often used in the engineering field has emerged. Compared to other standard materials, metal foams or metfoams constitute a new class of materials, known to have many interesting combinations of physical & mechanical properties.
Target Applications, Hurdles
Since the possible fields of applications of metal foams are very large, this project has the ambition to tackle the challenge of proposing a numerical/experimental methodology in order to create the design tools for next generation metal foams conception & optimization, by not only characterizing but also proposing & determining the more adapted macro/micro scale pore structure for each specific application. We shall mainly focus on developing a methodology for the design of high performance compact heat exchangers and heat sinks, e.g. in the context of the thermal management of direct thermo-electric converters or electronic devices coolers, for instance in the context of LED thermal management. Above the enhanced thermal conduction or the desired filtering, undesired particulate fouling is a common phenomenon in porous media/metal foams and may dramatically reduce the heat transfer efficiency.
Main objectives
The main research objectives are to:
- develop a numerical framework based on an Immersed Boundary Method (IBM) including a Level-Set technique for tracking the complex fluid/solid interface,
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- incorporate physical interactions between turbulent flow, particles and heat transfer in complex porous structures within the proposed framework while preserving high-order accuracy (using adapted versions of DEM, Discrete Element Method);
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Geometries proposed for the model development, from the simplest one to the full 3D foam geometry a) 2D cubic array b) 3D cubic array c) 3D Weaire-Phelan periodic cell (Boomsma et al. 2003) d) full 3D reconstruction (Lefebvre, 2007)
- apply the validated numerical framework to identify the key contributing parameters to fouling mechanisms and its mitigation in porous metal foams in turbulent heated flows.
Preliminary DNS Results
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Velocity contours at \(Re_H=\)𝟏𝟏𝟎𝟎𝟎 (\(Re_D=\) = 𝟒𝟖𝟎𝟎 to 𝟔𝟎𝟎𝟎, \(U_\infty=\)0.12 \(m.s^{-1}\)) on different idealized pore shapes (a) cylinder, (b) square, (c) longitudinal ellipse, (d) transversal ellipse.
Participants
Emilie Sauret, Sofiane Khelladi, Thomas Sarfati, Lucas Manueco, Eric Herbert, Yves D'Angelo.