| The contact melting of phase change materials, ice and n-octadecane, within a rectangular enclosure are experimentally investigated under the influences of various vibrations. Isothermal wall condition is maintained at the test cells with three typical aspect ratios of 0.4, 1.0, and 2.5, respectively. The solid-liquid interface contour is videotaped to obtain the melted volume fraction. It is shown that melting rates are increased under vibrating conditions and melting enhancement is proportional to the acceleration of vibration. Compared to the stationary experiments, the maximum melting rate enhancement of 170 percent is observed in ice melting. Aspect ratio plays an important role in phase change heat transfer mechanism and the lowest melting rates occur in both stationary and vibrating conditions for aspect ratio of 1.0. The relative melting enhancement by vibration for both high and low aspect ratio cases are significant. The increase of melting due to vibration is more pronounced at the low Stefan numbers. The present experiments indicate that horizontal vibration can be more effective than vertical vibration to enhance the melting rate. Preliminary theoretical analysis is also given to explain the complex phenomena of contact melting with the effect of vibration. |
