Experimental investigation on melting heat transfer of an organic material under electric field

In this paper the melting heat transfer process of n-octadecane when confined in a cylinder-cubic cavity under the influence of an electric field is experimentally investigated. n-octadecane is a typical organic phase change material (PCM) and possesses a well-defined melting point. The cylinder is subject to the simultaneous actions of electric potential and heating, while the bottom wall or the four sidewalls of cavity are grounded. The effects of the voltage's magnitude and polarity on the solid-liquid phase change heat transfer performance are studied. The dynamic evolutions of the melting front and liquid fractions, the measurement of velocity field and electric current-voltage characteristics, and the distribution of electric field are presented to understand the physical mechanism. It is observed that when the applied voltage is higher than a certain threshold charge injection at the cylinder takes places, and the resulting strong Coulomb force promotes melting. In addition, heat transfer enhancement is more significant when the charge injection takes place at a negative voltage. The strong electric field that surrounds the whole cylinder with the four grounded sidewalls would facilitate injection and accelerate phase change. In this case, the melting time can be reduced by up to 68.0% when the -25.0 kV is applied.

Automated summary

This paper experimentally investigates the melting heat transfer process of n-octadecane confined in a cylinder-cubic cavity under the influence of an electric field. It is found that when the applied voltage is higher than a certain threshold, charge injection at the cylinder takes place, leading to melting promotion. Heat transfer enhancement is more significant when charge injection occurs at a negative voltage, resulting in a reduction of melting time by up to 68.0% with -25.0 kV applied.