دانلود رایگان مقاله ذوب در داخل کپسول افقی استوانه ای

Abstract

The role of natural convection on solid-liquid interface motion during constrained melting within a horizontal cylindrical capsule was investigated. A numerical code is developed using an unstructured finite-volume method and an enthalpy porosity technique to solve for natural convection coupled to solid-liquid phase change. Flow patterns for different Rayleigh numbers are presented. The resulting melt shapes and the temperature in the PCM provide conclusive evidence of the importance of natural convection on heat transfer in the melt region.

6. Conclusion

This paper investigates numerically the effect of the Rayleigh number on the natural convection during the melting process within a horizontal cylinder. It is found that the melting process of PCM is dominated by conduction at early stages indicated by concentric solid–liquid interfaces parallel to the circular heated wall. At later times, natural convection is augmented and this affects the shape of the melting front and consequently results in unsymmetrical melting about the horizontal axis of the capsule. The numerical results indicate also that for low Rayleigh number, the flow in the melting zone remains in the stable state as the viscous force is dominant. At the high Rayleigh number, the Rayleigh-Bénard convection indicates an orderly behavior without been affected by the base flow.