Effects of pulsed and continuous jet vortex generators in a turbulent boundary layer flow an investigation using two highspeed stereo PIV systems

Abstract

Two highspeed stereo PIV systems have been used for the characterization of pulsed and continuous jet actuators in the turbulent boundary layer wind tunnel at ONERA Lille. The test aimed at generating an aerodynamic database useful for the characterization of (unsteady) vortical structures responsible for the wallnormal fluid exchange which enable an increase of wallshear stress in the wake of the jet actuator row. Averaging over all velocity measurements of the dataset without regarding the different cyclephases of the jet pulses and calculating the respective scalars and RMS values is the first step in the analysis of the time series of velocity fields. The second step is averaging the different phaselocked positions per cycle so that a quasitimeresolved reconstruction of the phase average induced vortical wake flow could be realized. Then, a comparison between continuous and pulsed jets through several criteria and an estimation of the minimal number of independent samples in a typical turbulent boundary layer were performed. This work has been realized in close collaboration between ONERA DAAP in Lille, France and DLRASEXV in Göttingen, Germany. Freigabe