Minimum film-boiling quench temperature increase by CuO porous microstructure coating

Abstract

Increase in the minimum film-boiling quench temperature, T-MFB, is achieved with microstructured CuO particles, and attributed to local cooling (fin effect) by the microstructure causing liquid-solid contact. A periodic structure is obtained using electrochemical deposition of 1 mu m diameter particles on brass sphere diameter 15mm forming unit-cell porous cones of average height L = 100 lm and base diameter D = 20 lm. Fin analysis predicts the cone tip cooling to the homogeneous nucleation temperature of water (similar to 330 degrees C), while the base temperature is at 600 degrees C. This causes liquid-solid contact during quenching, and analysis suggests the fin effective thermal conductivity hki and fin characteristic length L-2/D are key to this liquid-solid contact that influences TMFB. Published by AIP Publishing.