2001 Volume 21 Issue 1Supplement Pages 117-120
To analysis of a complex three dimensional flow structure of axial flow fan and determine the validity of its application, PIV system should be provided detailed space and time resolved experimental data for understanding and control of flow field. The high resolution stereoscopic PIV system, in this study was successfully employed at the investigation of flow structure near the axial flow fan. Using the once-per-resolution signal from the rotor, image fields were captured at a fixed poison of the blades and hence provides the ability to do phase-averaging. The three-dimensional instantaneous velocity fields and phase-averaged velocity fields, instantaneous and mean vorticity distributions and turbulent intensity of the stereoscopic PIV measurement result were represented at typical planes of the flow field. Phase-averaged velocity fields were calculated based on 200frames of the instantaneous stereoscopic PIV measurement results. From the velocity distribution, the vorticity and turbulent intensity distribution, which was known to be major factors of fan noise were calculated and its diffusion was discussed as they travel downstream. From the reconstructed three dimensional velocity iso-surface which is based on stereoscopic PIV results at 8 cross planes of the outlet flow fields, the three dimensional features can be seen clearly.
