Optical Measurement of Wall Shear in High Reynolds Number Flows
Abstract
Optical micro shear stress sensors have been successfully used in laminar and turbulent boundary layers in water and air. It has been determined that the sensor can measure wall shear with 99% accuracy in laminar boundary layers with thicknesses as low as 400 microns. It has also been established that the shear stress sensor can measure the wall shear with 95% accuracy for turbulent flows with Reynolds number as high as 2.0 x 10^6. Recent measurement of the wall shear at the Navy's Large Cavitation Channel (LCC) has demonstrated that the wall shear in high Reynolds number flows can be obtained with the micro shear stress sensor. The measurement errors were less than 6% for flow Reynolds numbers of up to 1.6 x 10^8. This was achieved through an iterative technique using assumed global velocity profile.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2003
- Bibcode:
- 2003APS..DFD.MA006M