Session Ca - Turbulent Jets & Wakes.
ORAL session, Sunday, November 23
301, Moscone Center
(Supported by Procter amp; Gamble) The applications for jets in crossflow are extraordinarily varied, resulting in a wide range of flow parameters and geometries. The interaction among various parameters and the details of the resulting flow structures must be better understood to enable advances in predictive and design capabilities. This study involves an unusual geometry with a confined rectangular jet in crossflow. The parameters studied include six injection angles (18, 24, 30, 48, 60, 90 degrees), three velocity ratios (0.5, 1.0, 1.5) and five downstream distances corresponding to (3, 6, 9, 12, 15) jet diameters. A 2-D planar Mie scattering technique was used to evaluate the relative mixing effectiveness of the various configurations. In addition, a laser Doppler velocimeter (LDV) was used to map velocity fields corresponding to the scalar concentration data for several conditions. Large-scale secondary flow patterns and asymmetries in the scalar concentration are the signatures of prominent vortic! al! flow structures. These results are compared to others from a wide variety of different geometries to characterize the critical structural features in this flow which control its behavior.