Application of two-component phase doppler interferometry to the measurement of particle size, mass flux, and velocities in two-phase flows

The application of two-component interferometry is described for the spatially-resolved measurement of particle size, velocity and mass flux as well as continuous phase velocity. Such a capability is important to develop an understanding of the physical processes attendant to two-phase flow systems, especially those involving liquid atomization typical of a wide class of combustion systems. Adapted from laser anemometry, the technique (phase Doppler interferometry) measures single particle events at a point in the flow. Droplet size is deduced from the spatial phase shift of the Doppler signal. Combined with conventional laser anemometry for the resolution of velocity, the added capability of sizing allows for the discrimination of the discrete phase velocity statistics from those of the continuous phases as well as the particle mass flux. Applications are presented for four cases: an example of the discrimination of two sizes of glass beads in a jet flow, a demonstration, of the discrimination of phases in a spray field, an assessment of atomizer symmetry with respect to fuel distribution, and a characterization of a droplet field in a reacting spray. In addition, the limits of applicability are discussed. © 1997 Combustion Institute