Two phase pressure drop across abrupt area changes

The research was undertaken to develop a coherent view of two-phase pressure drop across abrupt area changes during steady flow. The objectives of the program were to establish an additional data base of observations of two-phase pressure drop across abrupt area changes, and to determine whether a single model based one-dimensional momentum theory can correlate the data obtained in the present investigation as well as that in the literature. Examination of the data available in the literature indicated that most of the pressure drop measurements across abrupt area changes were made with the steamwater system. To assure the generality of the correlating approaches developed, it was decided to conduct the test program with a nonwater system. The freon-freon vapor system was selected for this purpose.