Measurement of Vapor Superheat in Post-Critical-Heat-Flux Boiling

A differentially-aspirated superheat probe was developed to measure vapor temperatures in post-critical-heat-flux, dispersed-flow boiling. Measurements obtained for water, at low-to-moderate pressures and mass flow rates in a tube, indicated very significant nonequilibrium, with vapor superheats of several hundred degrees (/sup 0/C). Predictions of published correlations showed unsatisfactory agreement with the experimental results.