Jets in a Crossflow: Effects of Geometry and Blowing Ratio

Abstract

The flow field characteristics of three different geometries of square jets in a crossflow at various blowing ratios are examined. The geometries considered are: perpendicular, streamwise-inclined, and spanwise-inclined jets. The inclined jets are at a 30 deg angle to the wind tunnel floor. Mean velocity and turbulence measurements along with film cooling effectiveness and scalar transport data were obtained. Jet-to-crossflow blowing ratios of 1.5, 1.0 and 0.5 are used with a density ratio of 1. It is shown that the flow field at the jet exit is strongly influenced by the crossflow as well as by the inlet conditions at the entrance to the jet orifice. The strong streamline curvature which is present in the perpendicular and spanwise injection cases appears to result in the greatest turbulence anisotropy. The film cooling effectiveness is best at the lowest blowing ratios as the jet is deflected strongly towards the floor of the wind tunnel, although the improvement is more significant for the streamwise injection case.