Study of ultrasonic enhancement in melting process of phase-change materials

Experimental results of ultrasonic enhancement in melting phenomena were reported in this paper. Three different cases of experimental investigation have been conducted: (1) melting of a water-frozen porous body in warm water, (2) melting of an ice cube floating in warm water, and (3) melting of paraffin (99 percent n-octadecane) in a rectangular enclosure. The results showed that the application of ultrasonic vibrations enhanced the melting process of phase-change material. For the melting of paraffin in an enclosure, for instance, the application of ultrasonic vibrations at 55 KHz enhanced the melting process about 2.5 times greater than the natural melting case (without ultrasound). It was also observed that as the frequency of vibrations increased the melting process increased until the frequency reached an optimum value.