Investigation of Melting in a Vertical Circular Tube: Local Heat Fluxes

Abstract

The present study explores the process of melting of a phase change material (PCM) in a vertical circular tube. A detailed analysis of the digital experimental pictures, obtained in previous investigations, is performed. In this analysis, the tubes are subdivided by horizontal planes into 1cm high slices. The melt fraction as a function of time is calculated separately for each slice, yielding the local heat transfer rates into the solid. The flow patterns that cause these effects are obtained from the numerical simulation. The simulation provides a detailed heat flux distribution on the inner wall of the tube. The numerical simulations, performed using the Fluent 6 software, model the same commercially available paraffin-type material that was used in the previous experimental investigations.. The simulation results, along with the analysis of the experimental pictures, reveal the effects of convection in the liquid phase, which make heat transfer from the wall to the melting PCM essentially non-radial. Thus, the analysis adopted in the present study provides a comprehensive picture of melting in vertical circular tubes at various locations and instants.

Numerical modeling of fluid dynamics and heat transfer of glass flow in a short channel

“…In most cases, an over-relaxation factor is used to accelerate the convergence of the iteration. Shmueli et al (2008) investigated the process of melting of a phase change material in a vertical tube. The numerical simulations were done with fluent and the flow patterns and a detailed distribution of heat transfer on the inner wall of the tube were obtained.…”

Simulation of the solidification in a channel of a water-cooled glass flow

“…In most cases, an over-relaxation factor was used to accelerate the convergence of the iteration. Shmueli et al (2008) investigated the process of melting of a phase change material in a vertical tube. The numerical simulations were done with FLUENT and the flow patterns were obtained with a detailed distribution of heat transfer on the inner wall of the tube.…”