Structured surfaces for enhanced pool boiling heat transfer

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 similar to 208W/cm(2) was achieved with a surface roughness of similar to 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. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4724190]