Experimental study of steam-water choked flow

Experimental results of choked flow in steam-water mixtures at low pressures (1.5 to 2.0 bar) and at low qualities (less than 0.01) are presented. The loop and the different test sections are described. The procedures for the measurement of temperatures, flow rates, and pressures are given. Emphasis is put on the void fraction measurements by X-ray attenuation. With the glass test section, vizualizations and measurement of radial void fraction profiles by X-ray attenuation have led to the determination of flow patterns. Axial void fraction and pressure profiles measured on the stainless steel test section are presented. Nonequilibrium temperatures have been measured and varied by putting grids into the flow. The importance of nonequilibrium effects like the delay on onset of vaporization, cavitation and the limitations of vaporization have been shown