Effect of noise in laser doppler anemometry

✍ Scribed by S. Gerosa; G.P. Romano

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 393 KB
• Volume: 8
• Category: Article
• ISSN: 0888-3270
• DOI: 10.1006/mssp.1994.1018

✦ Synopsis

The problem of obtaining velocity information from laser Doppler anemometry (LDA) measurements is complicated by the presence of noise. Both electronic and optical noises are superimposed on the Doppler signal, acting as frequency modulators. In this paper an advanced spectral analysis method has been applied, in order to point out the influence of optical noise in experimental measurements and compare it with theoretical predictions. The optical configuration with minimum noise level is used for the investigation of a fully developed turbulent channel flow. The departure of this flow from the Taylor hypothesis of frozen turbulence has been studied and a comparison between the double spatial correlation and the single point time auto-correlation of longitudinal velocity component has been performed.