Experiments on the Injection of a Circular Jet into a Wake of an Airfoil. Mean Flow Properties.

Abstract

An experimental study has been performed on the three-dimensional mixing process in a circular jet which was injected into each wake of a two-dimensional symmetrical airfoil that was fitted with attack angles of 0° and 5° in a uniform flow. The results were compared with the that in the case of injection into the wake of the circular cylinder which has been examined by us previously. The profile of mean velocity relative to the wakes in the cases of the airfoil with the attack angles of 0° and 5° is axisymmetric, which agrees almost with the Gaussian profile. The decay of the relative maximum velocity takes place with the difference owing to the variation of the surrounding wake field. In all cases, the half width which was determined from the relative velocity distribution obeys the power law. In the case of the attack angle of 0°, the length scale shows symmetry, but in the case of the attack angle of 5°, the length scale shows asymmetry. It confirmed that this phenomenon is produced by the secondary flow.