Experimental Investigation of the Mean Liquid Film Thickness and the Characteristics of the Interfacial Surface in Annular, Two-Phase Flow.

摘要

This paper presents some of the results of an experimental investigation of annular, two-phase flow conducted in a vertical tube, 2.498 in. ID and 28 in. long, employing thin water films (thickness < 0.020 in.) and a co-current flow of air. The experiments were conducted at ambient temperatures and pressures. The effect of the rates of flow of the air and the water upon the mean thickness of the liquid film and upon the pressure gradient in the gas stream were determined, although the latter was of secondary interest. Photographic records were made of the oscilloscope traces corresponding to the profiles of the gas-liquid interface at on point in the tube as a function of the rates of flow of the two fluid media. An exploratory experimental study was conducted for determining the region of disturbance instability wherein the crests of the interfacial waves are torn off and carried into the gas stream in the form of droplets. The liquid Reynolds number was varied from 17 to 1780; the Reynolds number of the air, when it differed from zero, was varied from 50,000 to 303,000. The results indicate that the amplitudes and frequencies of the interfacial waves are related by definite spectra which characterize the structure of the interfacial surface. It appears further that the interfacial structure influences the flow of the gas in a manner similar to that of wall roughness in pipe flow. (Author).