Effect of non-Poisson samples on turbulence spectra from laser velocimetry
Abstract
Spectral estimations from LV data are typically based on the assumption of a Poisson sampling process. It is demonstrated here that the sampling distribution must be considered before spectral estimates are used to infer turbulence scales. A non-Poisson sampling process can occur if there is nonhomogeneous distribution of particles in the flow. Based on the study of a simulated first-order spectrum, it has been shown that a non-Poisson sampling process causes the estimated spectrum to deviate from the true spectrum. Also, in this case the prefiltering techniques do not improve the spectral estimates at higher frequencies.
- Publication:
-
AIAA Journal
- Pub Date:
- December 1994
- Bibcode:
- 1994AIAAJ..32Q2480S
- Keywords:
-
- Axial Flow;
- Laser Doppler Velocimeters;
- Nyquist Frequencies;
- Poisson Density Functions;
- Sampling;
- Spectrum Analysis;
- Turbulence;
- Laser Applications;
- Light Scattering;
- Mathematical Models;
- Stochastic Processes;
- Fluid Mechanics and Heat Transfer