Subcooled water jet quenching phenomena for a high temperature rotating cylinder

Quenching characteristics of a rotating hollow steel cylinder with 15 mm water jet having flow rate of 6-10 L/min has been experimentally investigated. The jet with 60-80 K subcooling was impinged on the horizontally rotating (0, 15, 30 and 60 rpm) 460-560 °C hot cylinder. A developed inverse solution estimated surface temperature and heat flux from measured temperatures during quenching. Surface rotation created a non-uniform cooling which resulted in a non-uniform distribution of wetting front (leading edge of visible vigorous boiling region). Surface velocity (rotation) strongly influenced relative velocity between solid and liquid which affected the surface heat transfer during cooling. As the cylinder rotated and the jet was fixed, the surface heat flux fluctuated which was followed by the surface temperature. Heat transfer from a relatively faster moving surface was smaller but due to periodic cooling, bulk temperature reduced more. The estimated heat flux agreed reasonable with static surface critical heat flux in literature especially for the trend with radial position. The produced boiling curves were well compatible with some of the compared correlations in nucleate boiling region.