Structured surfaces for enhanced pool boiling heat transfer

TLDR

The study fabricated microstructured surfaces with varying roughness and extended an analytical force‑balance model to explain the observed CHF enhancement, achieving a maximum CHF of ~208 W/cm² at a roughness of ~6. Model–experiment agreement confirms that roughness‑amplified capillary forces drive CHF enhancement, providing design guidelines for high‑heat‑removal structured surfaces.

Abstract

We experimentally investigated surface roughness-augmented wettability on critical heat flux (CHF) during pool boiling with horizontally oriented surfaces. Microstructured surfaces with a wide range of well-defined surface roughness were fabricated, and a maximum CHF of ∼208 W/cm2 was achieved with a surface roughness of ∼6. An analytical force-balance model was extended to explain the CHF enhancement. The excellent agreement found between the model and experimental data supports the idea that roughness-amplified capillary forces are responsible for the CHF enhancement on structured surfaces. The insights gained from this work suggest design guidelines for new surface technologies with high heat removal capability.