NOMENCLATURE

An experimental investigation on two-phase frictional pressure drop of water-vapor mixture was conducted in a vertical rectangular narrow channel. The present experimental data were carefully analyzed and compared against the homogenous model, including several well-known two-phase viscosity models. The results reveal that the models using two-phase viscosity proposed by Cicchitti and Dukler provide the relatively accurate predictions, while McAdams, Beattie-Whalley, Lin and Awad-Muzychka poorly predicted the database. Considering the effects of surface tension, gravity, channel size and mass flux, a new correlation for two-phase frictional pressure drop in rectangular narrow channel was developed based on the Cicchitti model. The new correlation predict the experimental data with a mean deviation of 18.7