FIBER OPTIC SENSOR SYSTEM FAR VOID FRACTION MEASUREMENT IN AQUEOUS 2-PHASE FLUIDS

An improved method of measuring the void fraction in two-phase mixture s has been developed. This work was part of a three-phase project that included proof-of-principle, design and fabrication, installation and probe use during a series of flow channel tests. The sensing method i s based on measurement of differences in infrared transmission through liquid water as result of the presence of vapour bubbles in the optic al path. The fibre optic system measures void fraction in a small volu me along a line-of-sight across the flow channel. This paper covers th e design and test of the fibre optic void fraction system, and applica tion results are presented on the measurement of two-phase mixtures in flow channels.