A conjugate heat transfer model for unconstrained melting of macroencapsulated phase change materials subjected to external convection
Hummel D, Beer S, Hornung A (2020)
Publication Type: Journal article
Publication year: 2020
Journal
Book Volume: 149
Article Number: 119205
DOI: 10.1016/j.ijheatmasstransfer.2019.119205
Abstract
A new conjugate heat transfer model for unconstrained melting of macroencapsulated phase change material subjected to external convection is presented. Flow and heat transfer processes are modeled for the phase change material, the capsule wall and the external heat transfer fluid. The solvers for each region operate in a segregated and sequential manner and are coupled by mixed thermal boundary conditions. For the description of the solid body motion in unconstrained melting, the enthalpy-porosity method is modified. The solid body surface is reconstructed from the liquid volume fraction field for every time step by a triangulated isosurface using a marching tetrahedra technique. Based on computation of the forces exerted on the solid, the motion of the solid is determined iteratively in a strong coupling between solid velocity and pressure. The new conjugate heat transfer solver is utilized to simulate the commonly experimentally and numerically investigated scenario of a spherically encapsulated phase change material immersed in a water bath. The coupled flow and heat transfer is investigated for a natural convection dominated mixed convection problem with a Richardson number of 50 · 103 and Stefan numbers of 0.075, 0.1, 0.15, 0.2 and 0.25. Contrary to the commonly made assumption, the resulting capsule wall temperature is transient and highly non-uniform. The differences in melting times range from 50.7 to 67.5% between the consideration of external heat transfer and the assumption of constant uniform wall temperatures.
Authors with CRIS profile
Daniel Hummel
Lehrstuhl für Hochtemperaturprozesstechnik
Andreas Hornung
Lehrstuhl für Hochtemperaturprozesstechnik
Involved external institutions
Germany (DE)How to cite
APA:
Hummel, D., Beer, S., & Hornung, A. (2020). A conjugate heat transfer model for unconstrained melting of macroencapsulated phase change materials subjected to external convection. International Journal of Heat and Mass Transfer, 149. https://dx.doi.org/10.1016/j.ijheatmasstransfer.2019.119205
MLA:
Hummel, Daniel, Stefan Beer, and Andreas Hornung. "A conjugate heat transfer model for unconstrained melting of macroencapsulated phase change materials subjected to external convection." International Journal of Heat and Mass Transfer 149 (2020).
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