Measurements of Atomized Droplet Flow by a Four-Beam Fiber Optic LDV System

The presence of particles or water droplets in the flow of turbomachinery, especially in the low pressure stages of a wet steam turbine, leads to the erosion on the moving blades and causes the increase of energy loss. Therefore, there is a growing demand for measuring the behavior of these particles directly in order to evaluate and prevent the blade erosion. This report is concerned with the measuring technique of droplet sizing and velocity in the atomized droplet flow by a four-beam fiber optic LDV system. The optical system makes two coaxial volumes with different diameters and droplet sizes are evaluated by light scattering intensity. The results of experimental calibration using a monodispersed droplet generator with the vibrating orifice indicate good agreements with those of microscopic measurements. Finally, this paper shows the results recorded in the atomized droplet flow at different chamber pressures.