THE USE OF FLUORESCENCE IN THE MEASUREMENT OF LOCAL LIQUID CONTENT IN TRANSIENT MULTIPHASE FLOWS

The theoretical basis of a technique we proposed recently for the measurement of local-instantaneous liquid fractions in highly dispersed two-phase flows is developed. The technique is based on the measurement of ultraviolet-induced fluorescence, and the theoretical approach is to carry out numerical experiments accounting for refractions in the radiation transport path and for the randomness in the flow field (i.e., droplet positions and sizes). These numerical experiments indicate that for a properly selected measurement volume (defined by positioning of the fibers) refractions have a small impact and the measurement is predictable and robust. We also present experimental data that demonstrate this excellently predictable behavior.