Two phase pressure drop across abrupt area changes

This research was undertaken to develop a coherent view of two-phase pressure drop across abrupt area changes during steady flow. Specifically the objectives of this program were to: establish an additional data base of observations of two-phase pressure drop across abrupt area changes; and 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. The Freon-Freon vapor system was selected for this test program. An available loop, capable of producing a mixture of Freon liquid and vapor, was modified for these tests. The first part of the experimental program consisted of a series of observations of the transition from homogeneous to non- homogeneous flow. The bulk of the experimental observations were devoted to abrupt area change pressure drops. The data obtained and the available information from the literature were tested against several predictions based upon a one-dimensional momentum balance. (22 references) (U.S.)