Movement of maximum heat flux and wetting front during quenching of hot cylindrical block

An experimental work is carried to study the characteristics of heat transfer and wetting front during quenching high temperature cylindrical block by water jet at atmospheric pressure. The surface temperature and heat flux are estimated by applying a two-dimensional inverse solution. The movements of both wetting front and transition boiling region over the heated block surface were observed using a high speed video camera. The surface temperature and heat flux over the whole surface during quenching could be estimated well. The surface temperature, the position and the time at which the maximum heat flux occurs are obtained. It has been found that the maximum heat flux occurs neither in the wetting front, nor in the transition boiling region but in the fully wetted region. It has also been found that the maximum heat flux dose not start at the same time when the jet water strikes the heated block, but it starts when the surface temperature decreases to a value less than 170 degreesC. (C) 2004 Elsevier SAS. All rights reserved.