Phase-change heat transfer of bare surface evaporator with phase-separating wick in downward facing orientation
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Egbo, M., & Hwang, G. (2021). Phase-change heat transfer of bare surface evaporator with phase-separating wick in downward facing orientation. International Journal of Heat and Mass Transfer, 173 doi:10.1016/j.ijheatmasstransfer.2021.121206
Abstract
Liquid-vapor, phase-change heat transfer using wicks can provide reliable and high heat flux cooling capability, especially in microgravity applications. However, the maximum heat removal capacity, also known as Critical Heat Flux (CHF), is related to the capillary-driven liquid supply limit and/or vapor removal limit. A key is to develop a novel wick structure, offering efficient liquid supply as well as vapor removal pathways. In this study, the Bare Surface Evaporator with Phase-Separating Wick (BEPSW) is examined to understand the liquid supply and vapor removal limits in a downward facing orientation for microgravity environment. The BEPSW consists of a bare surface evaporator for the efficient evaporation, and the distributed, sintered-particle post wicks with the phase-separating wick for enhanced liquid supply and vapor removal. The bare surface is fabricated from a copper disk 19.1 mm in diameter, while the post and phase-separating wicks are manufactured using 10 and 3 layers of sintered copper particles, respectively. The heat flux is measured as a function of the surface superheat for different post-post pitch distances (