Development of a comprehensive set of drift-flux constitutive models for pipes of various hydraulic diameters

The drift-flux model is one of the most significant models for the prediction of two-phase flows being used today, with applications in many fields of engineering. Even more advanced models such as the two-fluid model require the use of drift-flux based models as constitutive relations. For this reason, it is necessary that accurate models for the drift-flux parameters exist for various geometries and fluid systems. One of the main weaknesses in a comprehensive set of drift-flux models is a lack of well-developed models for large diameter pipes, especially at higher void fractions. Thus one major step towards defining a comprehensive set of drift-flux models is to verify models in large pipes. To this end, a review of previous experiments has yielded a database of void fraction information in large pipes. Additionally, experiments have been performed in tests sections with diameters of 0.15 m and 0.20 m with liquid velocities up to 1 m/s and void fractions up to 0.85 under two pressure conditions. A comprehensive set of drift-flux models has been recommended based on the new data and the previously existing data.