Melting transient process has been scrutinized in a wavy channel. The present storage unit utilized the benefits of dispersion of nanomaterial and wavy duct. Kind of nanoparticles and PCM are copper oxide and RT28, respectively. FVM with help of structure grid has been employed for this simulation. For validity of current code, obtained data was compared with experimental data. Outputs during melting phenomena were summarized in contours and plots. Temperature of hot air reduces in outlet section due to melting process. PCM gets the needed heat for melting from hot air. As solid fraction declines, lower heat transfer from air to PCM and consequently temperature of outlet augments. Air temperature enhances about 2.4% with rise of time from 5 to 50 h when a = 10 mm. As all solid converts to liquid, the average temperature of air and PCM become equal due to assumption of no heat loss from the domain. As move from point 1 to point 3, temperature increase because of existence of hot air flow near the 3rd point and this difference is more sensible for greater time in which lower solid fraction exist. At t = 20 h and 40 h, augmenting a leads to about 10.19% increament and 21.98% reduction in Q, respectively. Amount of Q is related to mass of solid and it reduces as time progress. At a = 10 mm, Q for t = 40 h is 2.61 times lower than that of t = 5 h. Amplitude of wavy duct can affect the temperature distribution and its influence is more observable in greater time. At t = 50 h, temperature of PCM reaches to 316.77 K which is very close to air average temperature in this time. Melting time has reverse relationship with efficiency of storage unit. Liquid fraction augments about 299.5% as time progress from 5 to 20 h when a = 5 mm. Utilizing nanomaterial and extended surfaces can boost the system in view of reducing in time of melting. At t = 5, 20 and 40 h, liquid fraction augments with rise of a by about 26.04%, 17.45% and 7.81%.