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

• Published in: Experimental thermal and fluid science Vol. 131; p. 110530
• Main Authors: Sun, Zhihao, Zhang, Yimo, Luo, Kang, Pérez, Alberto T., Yi, Hongliang, Wu, Jian
• Format: Journal Article
• Language: English
• Published: Philadelphia Elsevier Inc 01.02.2022; Elsevier Science Ltd
• Subjects: Asymmetric electrodes; Charge injection; Current voltage characteristics; Cylinders; Electric Field; Electric fields; Electric potential; Fractions; Heat transfer; Heat transfer enhancement; Injection; Liquid phases; Melting; Melting point; Melting points; Organic phase change materials (PCMs); Particle image velocimetry; Phase change materials; Polarity; Velocity distribution; Voltage; Heat transfer enhancement; Particle image velocimetry; Asymmetric electrodes; Melting; Organic phase change materials (PCMs); Electric Field
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2021.110530

[Display omitted] •Experiments on the influence of electric field on melting of n-octadecane inside a cylinder-cubic cavity are performed.•The Coulomb force rather than the dielectric force plays the central role.•The electric field would hinder or accelerate the melting depending on the charge generation mechanism.•Charge injected from the cylinder could significantly speed up melting. 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.