Session: K13-02: EVAPORATION AND POOL BOILING FROM ENHANCED SURFACES

Paper Number: 142381

142381 - Scaling for Critical Heat Flux During Pool Boiling of Micropillared and Sandblasted Surfaces 

Abstract: 

Boiling is a vital process used to transfer heat effectively via harnessing the substantial latent heat of vaporization for a variety of energy and thermal management applications. In our study, we delved into how surface structures influence the enhancement of critical heat flux (CHF) during pool boiling heat transfer conducted on hemi-wicking surfaces. Previous research has demonstrated that both roughness and wickability significantly influence CHF enhancement. These two parameters are intrinsically intertwined, however, complicating the analysis of their individual impacts on CHF values. To isolate and analyze the distinct effects of roughness and wickability on CHF values, we systematically designed micropillar surfaces with specific roughness and wickability parameters. Specifically, we created a series of micropillars with uniform roughness but different levels of wickability, and conversely, a set with consistent wickability but varied roughness. Integrating pool boiling experiments on micropillar surfaces with scaling analyses, we derived a unified descriptor for CHF values. This descriptor not only succeeded in capturing the effects of microfabricated surfaces but also demonstrated a linear relationship with CHF enhancements observed on micropillar surfaces. The study extended to incorporate a scalable manufacturing technique, sandblasting, aiming to broaden the application of our findings to industry-scale applications. We confirmed that our unified descriptor can capture the enhancement of randomly structured sandblasted surfaces as well. This correlation underscores the descriptor’s applicability in guiding the design and optimization of surface treatments to maximize boiling heat transfer performance. Our results offer a methodical approach to designing and evaluating surface treatments for enhanced boiling. By providing a bridge between small-scale laboratory experiments and large-scale industrial applications, our findings may pave the way for advancements in energy and thermal management solutions.

Presenting Author: Youngsup Song University of Florida

Presenting Author Biography: Youngsup Song is an Assistant Professor in the Department of Mechanical and Aerospace Engineering at the University of Florida. He obtained his Ph.D. in Mechanical Engineering from MIT, where he investigated multiphase heat transfer. Following his graduate work, he trained as a postdoctoral researcher at Lawrence Berkeley National Laboratory before joining the University of Florida.

Authors:

Youngsup Song University of Florida
Lenan Zhang Massachusetts Institute of Technology
Carlos Diaz-Marin Massachusetts Institute of Technology
Hyeongyun Cha University at Buffalo
Evelyn Wang Massachusetts Institute of Technology