Measurements of a longitudinal vortex generated by a rectangular jet in a turbulent boundary layer

Abstract

Measurements were made on the mean flowfield created through the interaction between a two-dimensional flat plate turbulent boundary layer on a flat plate and an inclined jet. The jet was generated by a nozzle of rectangular exit and was pitched and skewed to the oncoming flow. A total of three pitch angles and two jet velocity ratios were tested. The measurements were performed with a three-component laser Doppler anemometer system in a low speed wind tunnel. The dominant feature of the flow physics is a single longitudinal vortex produced as a result of jet/boundary layer interaction, with additional induced secondary features in the near-wall area in the spanwise direction. A salient feature of the flow is its maximum vorticity position which is located underneath the center of the vortex. Within the measured flow parameter range, the vortex development differs also from that of a round jet, differences in the velocity distribution are observed. The study provides contributions to flow physics.