Details of a Study of Interfacial Momentum Transfer in Two-Phase Two-Component Critical Flows

Abstract

<p> Preparations for an investigation of interfacial momentum transfer in two-phase two-component critical flows have been completed.</p> <p> The experiments involve the measurement of flow rates, axial pressure profiles, axial and transverse void fraction profiles, and axial wall shear stress profiles of steady-state gas-liquid critical flow in a vertical diverging nozzle. A photographic study is to be initiated to record the flow structure. The results of these experiments will be used to develop constitutive relations for interfacial momentum transfer.</p> <p> An experimental loop capable of circulating a gas-liquid mixture in a vertical test section was modified to suit the requirements of this investigation. The void fraction profiles are measured with a traversing gamma densitometer using a 20 mCi Co57 source. The wall shear stress profiles are obtained using the electrochemical method to measure the mass transfer coefficients of electrodes mounted flush with the test section wall. The liquid phase is an electrolyte and the gaseous phase can be air, nitrogen or freon. The latter is used to better approximate the densities of a steam-water flow.</p> <p> This report describes the required theory, measurement techniques, design and operation of the loop, and the experimental procedures.</p>