High frame rate PIV measurements
Particle Image Velocimetry (PIV) allows the instantaneous velocity field (the two in-plane components) to be measured on a two-dimensional plane in the flowfield. Two laser pulses, separated in time, illuminate small particles added to the flow. A special camera acquires the two images separately, then determines the local velocity by statistically interpreting the two images. Recently, TSI has developed a high frame rate PIV system, and they brought the system to our laboratory to make engine measurements. The movie shows the resulting velocity field (shown as vectors) overlaid on the vorticity field (shown as the color) on a horizontal plane of the engine during the intake and compression strokes. Clearly structures can be identified and followed during their evolution. These data allow, for the first time, the direct comparison of spatial and temporal filtering to identify the turbulence properties of an internal combustion engine.
Acknowledgements: This work was performed by Randy Herold and Tyson Strand (of TSI) was supported by TSI, Inc.
Publications: SAE Paper 2005-01-3968
For more information contact Prof. Ghandhi