AN LDV SYSTEM FOR MEASUREMENT OF SPATIAL VELOCITY CORRELATIONS IN TURBULENT GAS-FLOWS

An LDV system was built for the measurements of spatial correlations i n turbulent jets and diffusion flames. The basis of the system are two independent one-component optics which work in forward scattering mod e. One of this two optics is stationary, the second can be traversed i n all three spatial directions. With this equipment the spatial transv erse and longitudinal correlations in all three spatial directions can be measured. In a first step this system was applied for measurements in a cold air jet with the Reynolds number of 24 000. In this paper d etails of the equipment and of the data processing are explained and n ew results are shown. The results are compared to literature data and show good agreement.