## Abstract

The present study explores numerically the process of solidification of a phase change material (PCM) in cylindrical shells with a vertical axis. The material properties used in the simulations are based on a commercially available paraffin wax, which is manufactured to be used mainly in latentheat-based heat storage systems. A parametric investigation is performed for solidification in

cylindrical shells of 10, 20 and 40mm in diameter. The initial temperature of the system is uniform, at few degrees above the melting point of the material. The process starts with a step change in the wall temperature to a new uniform value, from 10°C to 50°C below the mean solidification temperature of the PCM. The bottom of the shell is either adiabatic or follows the wall temperature.

Transient numerical simulations are performed using Fluent 6.2 code. These simulations show the whole solidification process, and incorporate such phenomena as convection in the liquid phase, volumetric contraction due to solidification, and irregular boundary between the PCM and air.

Formation of curvilinear solid surface is demonstrated. Dimensional analysis of the results is attempted and presented as the PCM melt fractions vs. an appropriate combination of the Fourier and Stefan numbers.

cylindrical shells of 10, 20 and 40mm in diameter. The initial temperature of the system is uniform, at few degrees above the melting point of the material. The process starts with a step change in the wall temperature to a new uniform value, from 10°C to 50°C below the mean solidification temperature of the PCM. The bottom of the shell is either adiabatic or follows the wall temperature.

Transient numerical simulations are performed using Fluent 6.2 code. These simulations show the whole solidification process, and incorporate such phenomena as convection in the liquid phase, volumetric contraction due to solidification, and irregular boundary between the PCM and air.

Formation of curvilinear solid surface is demonstrated. Dimensional analysis of the results is attempted and presented as the PCM melt fractions vs. an appropriate combination of the Fourier and Stefan numbers.

Original language | English GB |
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Title of host publication | Proceedings of the 5th European Thermal Sciences Conference, Eindhoven, The Netherlands |

Number of pages | 8 |

State | Published - 2008 |