The present research is devoted to the numerical study of the effect of ultrasonic waves emitted from an ultrasonic transducer on the melting performance of a double-pipe latent heat exchanger system (LHS). In the considered LHSs, hot water passes through the inner tube and the phase change material (PCM) located in the annulus melts by taking heat from the water. The performance of the LHS systems including the ultrasonic waves were compared with the performance of common LHS systems in both horizontal and vertical situations. In contrast to conventional methods for enhancing the heat transfer, integration of ultrasonic source with LHS is the novelty of current research. It is followed by evaluating the effect of transduce position and power on thermal energy absorption. The ultrasonic transducers were installed in various positions to find the most suitable location for improving the heat transfer. The melting time of PCM decreased up to 56.63 % and 74.59 % by applying the ultrasonic field for horizontal and vertical LHS, respectively. In addition, the effect of the transducer power on the performance of the best horizontal and vertical LHS cases was investigated. It was found that the increase in the transducer power from 20 W to 150 W is associated with a decrease up to 40.83 % in the charging time of PCM. The obtained improvement of heat charging of LHS can be attributed to the intensifying the convective heat transfer through ultrasonic field.
