Stereo PIV measurement of diffuser swirling flow

The swirling flow in a diffuser has been studied using the stereo PIV technique. DANTEC hardware and software were used for experiment. water pipe inlet set spinning by introducing tangential jet flow. Both piping of circular cross-section, however casing had rectangular (square) cross-section. plane measurement was located perpendicular to within diffuser. two cameras with Scheinpflug lens mounting used, angle between lenses axes outer surface far from be perpendicular, as recommended similar situations. This configuration dictated technical conditions laboratory. two-level calibration target dots calibration. covers diffusers central region good quality, regions close walls not well resolved. Many combinations axial inflow have studied. acquisition covered about 3 seconds real time frequency 500 Hz. statistics dynamics details. Results are shown both statistical characteristics dynamical analysis various conditions. During experiments air-glass-water interface normal camera viewing axis. discussion how solve this problem bias will introduced.