Laser sheet dropsizing based on two-dimensional Raman and Mie scattering.

The imaging and quantification of droplet sizes in sprays is a challenging task for optical scientists and engineers. Laser sheet dropsizing (LSDS) combines the two-dimensional information of two different optical processes, one that is proportional to the droplet volume and one that depends on the droplet surface, e.g., Mie scattering. Besides Mie scattering, here we use two-dimensional Raman scattering as the volume-dependent measurement technique. Two different calibration strategies are presented and discussed. Two-dimensional droplet size distributions in a spray have been validated in comparison with the results of point-resolved phase Doppler anemometry (PDA) measurements.

Simultaneous application of single-shot Ramanography and particle image velocimetry.

A simultaneous two-dimensional determination of the concentration field and the velocity field in a turbulent mixing process is demonstrated for the first time to the best of our knowledge by using planar Raman scattering (Ramanography) and particle image velocimetry. An example of application of these techniques is tested by considering the mixing characteristic of a two-component nozzle for the injection of liquid ethanol into pure water.