2-PHASE FLOW MODEL-BASED ON LOCAL RELATIVE VELOCITY

Accurate estimation of the area-averaged volumetric fraction is requir ed when we evaluate two-phase flow characteristics such as pressure dr op and heat transfer. A two-phase flow model based on local relative v elocity was proposed in this study. The effects of distribution of loc al phase velocities and local volumetric fractions on the area-average d volumetric fractions were also taken into account in the model by in troducing new distribution parameters. In order to examine the applica bility of the model to the estimation of the area-averaged volumetric fractions, measured area-averaged volumetric fractions of solid-liquid flow and gas-liquid flow in vertical pipes were correlated based on t he basic equation of the model. The area-averaged volumetric fractions calculated with the correlation agreed well with the experimental dat a. Consequently, it was confirmed that the proposed model is a useful two-phase flow model.