TURBULENCE MODULATION IN AN INITIALLY QUIESCENT TWO-PHASE FLOW AT HIGH VOLUME FRACTIONS USING STEREOSCOPIC PIV

摘要

Turbulence data for 5 mm solid, spherical particles falling at terminal velocity through an initially quiescent vertical water channel are obtained using a Scheimpflueg stereo-PIV system. The system was successfully implemented into the flow facility and optimized to provide 3-D velocity field information for volume fractions at 2.71% and 5.24%. Vector validation played a significant role in reducing the data to obtain turbulence intensities as a function of particle fall time. The system was shown to be capable of measuring in-plane and out-of-plane displacements (velocities) with an error of less than 0.6%, despite blockage effects by the particles and inherent experimental errors. Since similar data in current literature is sparse, a popular length-scale model is provided in support of the data.