A free mixing layer is created by using a vertical twin-jet wind tunnel. Water droplets,
produced by an ultrasonic atomization type spray-nozzle are introduced in the higher
velocity side channel. Mean and fluctuating velocities are measured in case of both
single-phase and two-phase flow conditions. In this latter, a PTV-Sizing technique
is used to discriminate the droplets from the seeding particles. The changes in both
mean and turbulent quantities by the introduction of droplets could be measured by
the PTV- Sizing. Comparisons concerning turbulence modulation map between the present
study and existing results show good agreements.
