Final Report GARTEUR AD (AG22)

Kurzfassung

In the development of numerical codes for the prediction of aerodynamic flows, there is a strong need to obtain reliable flow field data, in particular to validate the turbulence models implemented in the Navier-Stokes equations. In three-dimensional boundary layer flows Laser Doppler Velocimetry (LDV) is the most appropriate technique usually applied to obtain these data. Since LDV, as a single point measurement technique is time consuming, it is desirable to be able to use experimental results coming from different research groups. Therefore, it is necessary to have a rational basis to compare measurements executed with different LDV processors and to define a consistent mathematical algorithm to process data from different LDV experiments. This was the objective of the present action of GARTEUR AD (AG22) involving four European research teams, from ONERA, INTA,FFA and DLR. The first issue was to be confident about the processing system. Although this point could have been considered as a resolved problem, it was decided to have four different signal processors and one aerodynamic and optical set up. In this way, the uncertainties coming from the possibly different optics were eliminated. The tests were done twice in two different wind tunnels (S3Ch at ONERA-Meudon and TWG at DLR-Göttingen) in order to make sure that conclusions gathered in one wind tunnel are still valid in another wind tunnel. Two calibration procedures were thus compared.