On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters

The recent literature has introduced the use of architected materials with a metallic lattice structure-based topology to enhance the thermal conductivity of phase change materials (PCM). The potential of such structures lies in the freedom of design with complex geometries. This, however, has intro...

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Main Authors: Stefano Piacquadio, Johannes Soika, Maximilian Schirp, Kai-Uwe Schröder, Sauro Filippeschi
Format: Article
Language:English
Published: MDPI AG 2023-10-01
Series:Thermo
Subjects:
Online Access:https://www.mdpi.com/2673-7264/3/4/34
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author Stefano Piacquadio
Johannes Soika
Maximilian Schirp
Kai-Uwe Schröder
Sauro Filippeschi
author_facet Stefano Piacquadio
Johannes Soika
Maximilian Schirp
Kai-Uwe Schröder
Sauro Filippeschi
author_sort Stefano Piacquadio
collection DOAJ
description The recent literature has introduced the use of architected materials with a metallic lattice structure-based topology to enhance the thermal conductivity of phase change materials (PCM). The potential of such structures lies in the freedom of design with complex geometries. This, however, has introduced novel challenges regarding the analytical description of these materials’ effective thermophysical properties, which are used in order to treat the composite as a homogenized material. Only a few limited works have been presented thus far that have holistically addressed the calculation of such properties. The wide variety of possible geometric parameters in these materials can only be appropriately treated via an adaptable approach that can be extended to upcoming lattice geometries. With this aim in mind, the present work introduces a method to calculate the effective thermal conductivity of the discussed composite PCM. A cell-based approach to calculate the effective thermal conductivity is introduced. The method makes use of Steinmetz’s solids as a basis from which one can derive the porosity of unit cells with variable geometric parameters. Empirical factors are introduced to account for limitations due to the complex geometry and eventual manufacturing imperfections of these structures. Thus, semi-analytical formulae to describe the effective thermal conductivity of the lattice cells are derived for a variety of cuboid and hexagonal prismatic unit cells with generic topological parameters. The formulae are validated against the models and experimental results present in the literature. Finally, an analysis and discussion of the limited validity of homogenization techniques for lattice structures is presented.
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spelling doaj.art-25525a0bd61b4283a97211c299acc83d2023-12-22T14:45:47ZengMDPI AGThermo2673-72642023-10-013456659210.3390/thermo3040034On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological ParametersStefano Piacquadio0Johannes Soika1Maximilian Schirp2Kai-Uwe Schröder3Sauro Filippeschi4Insitute for Structural Mechanics and Lightweight Design, RWTH Aachen University, Wüllnerstraße 7, 52062 Aachen, GermanyFaculty of Mechanical Engineering, RWTH Aachen University, Templergraben 55, 52062 Aachen, GermanyInsitute for Structural Mechanics and Lightweight Design, RWTH Aachen University, Wüllnerstraße 7, 52062 Aachen, GermanyInsitute for Structural Mechanics and Lightweight Design, RWTH Aachen University, Wüllnerstraße 7, 52062 Aachen, GermanyDepartment of Energy, Systems, TErritory and Constructions Engineering (DESTEC), University of Pisa, Largo Lucio Lazzarino, 56122 Pisa, ItalyThe recent literature has introduced the use of architected materials with a metallic lattice structure-based topology to enhance the thermal conductivity of phase change materials (PCM). The potential of such structures lies in the freedom of design with complex geometries. This, however, has introduced novel challenges regarding the analytical description of these materials’ effective thermophysical properties, which are used in order to treat the composite as a homogenized material. Only a few limited works have been presented thus far that have holistically addressed the calculation of such properties. The wide variety of possible geometric parameters in these materials can only be appropriately treated via an adaptable approach that can be extended to upcoming lattice geometries. With this aim in mind, the present work introduces a method to calculate the effective thermal conductivity of the discussed composite PCM. A cell-based approach to calculate the effective thermal conductivity is introduced. The method makes use of Steinmetz’s solids as a basis from which one can derive the porosity of unit cells with variable geometric parameters. Empirical factors are introduced to account for limitations due to the complex geometry and eventual manufacturing imperfections of these structures. Thus, semi-analytical formulae to describe the effective thermal conductivity of the lattice cells are derived for a variety of cuboid and hexagonal prismatic unit cells with generic topological parameters. The formulae are validated against the models and experimental results present in the literature. Finally, an analysis and discussion of the limited validity of homogenization techniques for lattice structures is presented.https://www.mdpi.com/2673-7264/3/4/34phase change materiallattice structuresadditive manufacturingeffective thermal conductivitythermophysical propertiesscale variance
spellingShingle Stefano Piacquadio
Johannes Soika
Maximilian Schirp
Kai-Uwe Schröder
Sauro Filippeschi
On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters
Thermo
phase change material
lattice structures
additive manufacturing
effective thermal conductivity
thermophysical properties
scale variance
title On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters
title_full On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters
title_fullStr On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters
title_full_unstemmed On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters
title_short On the Effective Thermophysical Properties of Phase Change Materials Embedded in Metallic Lattice Structures with Generic Topological Parameters
title_sort on the effective thermophysical properties of phase change materials embedded in metallic lattice structures with generic topological parameters
topic phase change material
lattice structures
additive manufacturing
effective thermal conductivity
thermophysical properties
scale variance
url https://www.mdpi.com/2673-7264/3/4/34
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