Mechanistic Model for Predicting Two-Phase Void Fraction for Water in Vertical Tubes, Channels, and Rod Bundles

摘要

A mechanistic model for flow boiling in vertical geometries is developed and is qualified against steady-state void formation data. Extensive testing versus rod bundle data is included.nThe model allows for subcooled void formation utilizing a modified Bankoff-Jones drift correlation. As established the model uses heat transfer and vapor generation correlations which are continuous over the full range of parameters but does not utilize flow regime maps.nThe correlations are qualified against tube, channel, and rod bundle voidage data for two models of the drift velocity Vgj. The qualification leads to excellent statistical agreement with the data.