Measurement of velocities in gas-liquid two-phase flow using laser Doppler velocimetry

Measurements of bubble and liquid velocities in two-phase flow have been made using a new forward/backward scattering Laser Doppler Velocimetry (LDV) technique. A standard LDV fiber optic probe was used to measure the bubble velocity using direct backscattered light. A novel retro-reflector and lens assembly permitted the same probe to measure the liquid velocity with direct forward-scattered light. Preliminary results show the usefulness of the technique in a duct of narrow thickness dimension.