"Re-wetting behavior and heat extraction during laboratory-scale quenching experiments using two probe geometries"

The effect of probe geometry on the re-wetting behavior and heat extraction of cylindrical probes during forced convective quenching in laboratory-scale equipment was studied. Flat-end and semi-spherical-end cylindrical probes made of AISI 304 stainless steel and instrumented with type-K thermocouples were considered. Two free-stream velocities (0.2 and 0.6 m/s) and two initial probe temperatures (850 and 950 °C) were studied. The quench medium was water at 60 °C.

The inverse boiling curves and videos obtained showed that the vapor film stage lasts longer when using flat-end probes. This delay in the start of re-wetting shifted the cooling curves to the right and favored the probe surface to reach lower temperatures before the start of re-wetting which resulted in slightly higher values of the wetting front velocity. It is shown that the hydrodynamics of the flow around the probe end is responsible for the differences observed between the two geometries.