Effects of surface modifications on pool boiling heat transfer with HFE-7100
Genesis Mlakar, Cho-Ning Huang, Chirag R. Kharangate
Abstract
This study explores pool boiling of HFE-7100 on copper surfaces. The key objective of this study was to examine the effects that surface modifications have on nucleate boiling performance. The surface enhancements studied are roughness, artificial nucleation sites, and a combination of both. Observing roughness between 0.480 μm to 7.564 μm shows that the heat transfer coefficient improves with increasing roughness. Observing hole diameters from 1 mm to 3 mm and hole pitch, or spacing to diameter ratio, from 1.75 to 3.5; a configuration with a hole diameter of 1 mm and pitch of 2.5 provides the best improvement to heat transfer coefficient compared to a bare surface with a roughness of 0.480 μm, while the configuration with a hole diameter of 1 mm and pitch of 3.5 provides worse heat transfer coefficient compared to a bare surface with a roughness of 0.480 μm. Applying a roughness to a hole pattern also improves the heat transfer coefficient with increasing roughness compared to both a bare surface with a roughness of 0.480 μm, as well as to the hole pattern alone. The majority of the surface enhancement modes yield overall improvements in heat transfer coefficient. The introduction of surface enhancement decreases critical heat flux across all samples.