Structural Characteristics of Dean Vortices in a Curved Channel.
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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Dean vortices in a curved channel were studied using flow visualization and a miniature Kiel probe to record total pressure. The channel is 1.27 cm. high by 50.8 cm. wide 0.5 in. x 20.0 in., aspect ratio of 40 to 1, with a radius of curvature of 60.96 cm. 24.0 in for the concave surface. Mean velocities within the curve channel were maintained at Dean numbers which ranged from 0 to 250. Smoke injected into the mouth of the channel at Dean numbers from 42 to 218 and locations from 65 deg to 145 deg revealed different types of flow behavior, including numerous pairs of Dean vortices extending from the convex to the concave wall. Different types off flow structures have been categorized as to unsteadiness, height, and symmetry. For each category a map has been constructed which depicts the flow structure observed as a function of Dean number and angular location. These maps and the photographs give an understanding of the flow behavior in the curved channel over a significant range of experimental conditions. Total pressure measurements at a Dean number of 110 and one location 118 deg were taken. The preliminary results are presented on a contour plot which shows some repeatability across a 2 in. portion of the channel span. These contour plot results are consistent with photographs for the same experimental conditions. Author
- Fluid Mechanics