Keywords: solidification, natural convection, density inversion, water, local entropy generation, phase change, annulus, circular tubes, local Nusselt number, heat transfer, temperature
Numerical study on solidification process inside annulus in presence of natural convection
In this study, solidification process of water around a circular tube is analysed with presence of natural convection and heat gain from surroundings. The present model is validated by comparing the numerical predictions with experimental data. Some considerably high agreements are achieved in terms of time–wise variations of interface positions and temperature values. After validating the numerical method, further analyses are conducted to examine the influence of initial temperature value of water on solidification process. Time–wise temperature, local Nusselt number and local entropy generation variations are presented together with the isotherms, streamlines, and entropy generation patterns. The results indicate that influences of the local entropy generation and natural convection become significant for the initial temperature that is higher than density inversion temperature of water. For the parameters studied, entropy generation as associated with heat transfer becomes a deterministic factor for all cases.