Article ID Journal Published Year Pages File Type
647799 Applied Thermal Engineering 2011 14 Pages PDF
Abstract

The present paper numerically analyzes a passive cooling system using enclosures with different geometries filled with thermal conductivity-enhanced phase change material (PCM). A numerical code is developed using an unstructured finite-volume method and an enthalpy-porosity technique to solve for natural convection coupled to a solid–liquid phase change. Five geometries containing the same volume of PCM are compared while cooling the same surface. The unsteady evolution of the melting front and the velocity and temperature fields is detailed. Other indicators of cooling efficiency are monitored, including the maximum temperature reached at the cooled surface. The computational results show the high impact of varying geometry: a maximum temperature difference as high as 40 °C is observed between two of the enclosures. The best efficiency is obtained for an enclosure shifted vertically relative to the cooled surface. Other findings and recommendations are made for the design of PCM-filled enclosures.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The shape of a PCM-filled enclosure impacts the cooling of a vertical surface. ► Its relative position is of great importance also. ► The best tested configuration is a slender geometry shifted vertically. ► This configuration reduces the maximum temperature at the surface by 40 °C. ► Part of the PCM should be placed above the surface, and none below it.

Related Topics
Physical Sciences and Engineering Chemical Engineering Fluid Flow and Transfer Processes
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