Measure of a low velocity component perpendicular to a high convection velocity - Application to the flow down a tee junction

This paper describes the LDA equipment and the procedure used to investigate a flow down a tee junction and to measure a low-velocity component perpendicular to a high convection velocity of a flow. A systematic optimization procedure was used, which made it possible to adjust data for the flow down a tee junction. The analysis of the results showed that the mean velocity does not provide real information. On the other hand, statistical variables such as variance and mode were consistent with other experimental information on the flow, such as the visualization. Data obtained on the probability density of the frequencies provided valuable information concerning the turbulence, oscillations, and bifurcations of the flow.