Abstract
Current study is about the charging process of paraffin within a tank with spiral duct. The paraffin has been enhanced with adding CuO nanoparticles. The hot fluid within the spiral pipes is hybrid nanomaterial. The fraction of nano-sized material is poorer than 0.04 and selecting single phase methodology is acceptable. Finite volume approach with including implicit method was applied to solve these transient equations. Grids with structural configurations were utilized for two suggested styles of containers. Verification with empirical data reveals that nice agreement exist for utilized mathematical model. Entropy generation components were measured and reported in contours forms. Also, important role of buoyancy force were reported in streamline contours. Increase of time leads to increase in liquid fraction in both cases and first configuration reach to maximum value in lower time. The amount of liquid fraction (LF) for first style is higher than second style which means better performance of first configuration. When time increase up to 80 min, the amount of LF for second and first configuration are 5.77 and 4.9 times bigger than those of t = 300 s. With rise of time, frictional irreversibility augments owing to augmentation of velocity of liquid paraffin. Also, with rise of volume of liquid paraffin, the temperature gradient ( backward difference T) reduces which provides lower value of thermal irreversibility. The first configuration has greater frictional entropy term while its thermal irreversibility is lower than second approach. With reduce of solid paraffin, temperature decreases and reaches to uniform value about 368 K. The first configuration has greater temperature and maximum difference occurs at t = 45 min.