An experimental study of Taylor's hypothesis in a quasi-two-dimensional turbulent soap film is presented. A two-probe laser Doppler velocimeter enables a nonintrusive simultaneous measurement of the velocity at spatially separated points. Using the cross correlation between a pair of points displaced in both space and time, the velocity coherence is measured to be better than 90% for scales less than the integral scale. Taylor's hypothesis is confirmed insofar as the lower moments of the longitudinal velocity difference are equal whether measured with or without invoking the hypothesis. A quantitative study of the decorrelation beyond the integral scale is also presented.
All Science Journal Classification (ASJC) codes
- Computational Mechanics
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Fluid Flow and Transfer Processes