Measurement of forced convection subcooled boiling flow and rod surface temperature distribution

Highlights: • High resolution temperature distribution along with a heated rod surface was measured. • Bubble transport behavior was three-dimensionally reconstructed, and turbulence velocity was obtained. • Void fraction and interfacial area transport, etc. for radial direction were measured with an optical double probe. • Forced convection subcooled boiling flow was measured simultaneously with the three measurement techniques and CFD-grade two-phase flow parameters were obtained. In order to obtain high-resolution data for modelling of boiling two-phase flow and its validation, we designed and constructed a test loop with a vertical annulus flow path and conducted subcooled boiling experiments to investigate subcooled bubble incipience and its development process under atmospheric condition. Three kinds of the state-of-the art measurement techniques were applied to quantify key parameters such as radial and vertical distributions of void fraction, bubble velocity, interfacial area concentration (IAC), Sauter mean diameters, high-resolution temperature distribution on rod surface, bubble transport behavior, and turbulent velocity components as well as onset of nucleate boiling (ONB), and onset of significant void (OSV).