Measurements of two-phase, air-water, flow in tube and annulus

Measurements of two-phase, two component (air and water), upward and downward flow through a vertical tube and an annulus were investigated. A new method for measuring two-phase flow in vertical tubes has been developed. In an annulus, the applicability of differential pressure transducers for identification of flow patterns was studied.; The new technique for two-phase flow measurements is different from a normal setup which commonly employs two or more devices, measuring different properties of parameters excluding temperature or pressure measurements. This new device, a Two Turbine Flow Meter (TTFM), was composed of two turbine flow meters and a valve with two thermocouples and two pressure transducers measuring local temperatures and pressures. From these measurements the volumetric flow rate of each phase was calculated. In the case of vertical upward flow in a tube, the output from TTFM gave an analytic solution, whereas in the downflow a numerical solution was required.; Differential pressure transducers were used in the annulus as flow pattern identifiers in the practical ranges of liquid flow rates (10-70 gpm) and air flow rates (0-28 scfm) both for the downward and upward flows. The probability density function (PDF) and power spectral density (PSD) of the pressure drop fluctuations were investigated. In both upflow and downflow analysis, PDF gave more information than PSD in flow pattern discrimination. In both cases, to obtain detailed information to classify flow patterns, the vertical measuring pressure tap distance should not be substantially larger than the annular gap.