Review on high speed applications of laser anemometry in France and Germany

The development and use of laser anemometry in various French and German high-speed wind tunnels is discussed. In these studies the fringe type anemometer was used exclusively because it is insensitive to vibrations and high sound levels. Moreover, this type of anemometer is supposed to give the most accurate results with respect to mean flow velocity and turbulence intensity. This is especially true if electronic counters are used as data acquisition systems. Both the optical arrangements and electronic designs are described in detail. All the investigations described relied on the natural dust particles present in the flow as velocity indicators. As a result of binational cooperation it is shown that in the wind tunnels considered the size distribution of dust particles fulfils almost completely the requirements of negligible particles lag. With some applications in high speed tunnel testing it is proved that laser anemometry is a standard measuring procedure, and that it yields results which may not be obtained by other methods.