Net Vapour Generation Onset During High Velocity Subcooled Boiling Flow:- A Simple Turbulence-Based Prediction Method

High velocity net vapour generation onset is examined by assuming that the onset criteria is that turbulence-induced temperature fluctuations permit pockets of saturated fluid which can contain vapour in subcooled regions of the flow away from the heated surface. This previously unconsidered concept was examined analytically and computationally, with wall nucleation effects on thermal hydraulics being neglected. Despite this simplification, both the analytic and computational studies support the basic concept, and provide predictive methods which in principle extend beyond the data range on which existing empirical predictive methods are based.