Accession Number : ADP005529

Title :   Laser-Two-Focus Velocimetry,

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V COLOGNE (GERMANY F R)

Personal Author(s) : Schodl,R.

Report Date : NOV 1986

Pagination or Media Count : 31

Abstract : This paper first reviews various publications about L2F-velocimetry with emphasis upon the important new advances of this technique. The manner of statistical data analysis of turbulent flows, including the simplified version which enables a time-saving measuring procedure, is described in some detail. The influence of beam diameter beam separation ratio on the measuring accuracy and on the measuring time is treated. The capability of the L2F-system at close-to-wall measurements could be further improved. Results of measurements in a very small flow channel and in a small turbocharger compressor rotor are presented. The 3-D version of the L2F-system was successfully operated recently. The principle, the optical set-up and the signal processing are described and some first results are presented. A comparison between laser doppler- and velocimeters gives answers about such signal properties as amplitude and rate, the smallest detectable particles and about the measuring time needed, based on the probe volume dimensions.

Descriptors :   *LASER VELOCIMETERS, TURBULENT FLOW, STATISTICAL DATA, STATISTICAL ANALYSIS, ACCURACY, LASER BEAMS, DIAMETERS, FOCUSING, SEPARATION, RATIOS, TURBOCHARGERS, SIGNAL PROCESSING, THREE DIMENSIONAL, WEST GERMANY

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE