Flow and heat transfer regimes during quenching of hot surfaces

Quenching experiments inside 6.0mm tube at reduced gravity

“…The relationship between the apparent rewetting temperature and rewetting temperature with the flow pattern during the rewetting process is represented schematically in Fig. 7, showing the complex vapour-liquid structures at the quench front according to the observations of Barnea et al [9]. The authors observed the vapour film extended upstream the rewetting front and occasionally some liquid droplets cooled the dry surface downstream the liquid front.…”

“…According to Westbye et al [2], Chen et al [7], Kim and Lee [8], and Barnea et al [9], the rewetting temperature is defined as the apparent rewetting temperature obtained by drawing the tangents to the transient temperature curves in the regions where the significant change of the curve slope occurs, as schematically drawn in Fig. 6.…”

“…Formally, and more theoretically, rewetting temperature, according to Barnea et al [9], is defined as the temperature of the surface at which a triple interface, vapour-liquid-solid, is formed. This temperature is very difficult to be obtained from measurements on the outer surface of the test tube.…”

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

“…The location of the maximum heat flux at the hot surface during quenching is very important for understanding the behavior of quenching phenomena. Most of the researchers [9][10][11][12][13] have found that the maximum heat flux occurred at the location of the wetting front position. Other researcher [14,15] found that the maximum heat flux occurs where nucleate boiling occurs.…”

Effect of Gravity on Film Boiling Heat Transfer and Rewetting Temperature during Quenching

“…1, replacing D by a capillary length (Berenson 1961) or a characteristic wave length of the Kevin − Helmholtz instability (Leonard et al 1977). Frederking and Clark (1962) proposed a correlation based on local acceleration instead of gravity for the quenching of a sphere, and more recently, some models of convective film boiling have been developed (Barnea et al 1994), with a local approach, by taking into account the local void fraction α 2 , or the vapor quality x 2 . Hammouda et al (1997) developed a modeling of flow film boiling on terrestrial condition also based on a local approach.…”