Study of Turbulence by Photon Correlation Spectroscopy
Abstract
We have studied grid-generated turbulence in a water tunnel at moderate Reynolds numbers. The method used was the standard one of Laser Doppler Velocimetry (LDV) and novel scheme, which we call photon homodyne correlation spectroscopy(HCS). With LDV, we measured the probability density function of velocity differences P(delta v(l)) on varying spatial scales l, by invoking the frozen turbulence hypothesis. The HCS technique permits measuring P without using this hypothesis. Of special interest to us was the behavior of the system at and above a Reynolds number (Re sub c) where the turbulence becomes self- similar, in that < (delta v) (l sq) > approx. l to the zeta power. Above Re sub c the exponent zeta increases from 0 to 2/3 with increasing Re.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 23, 1991
- Accession Number
- ADA243726
Entities
People
- W. I. Goldburg
Organizations
- University of Pittsburgh