Journal of Fluids Engineering · 1984 · 182 citations · 0 references
Natural SciencesAerospace EngineeringAerodynamicsFlow VisualizationFluid DynamicsBoundary Layer FlowBoundary LayersTurbulenceTurbulent FlowVortex DynamicsVortex VisualizationReynolds NumberWall Effects
The study investigates how end walls influence the size of the downstream secondary eddy in a three‑dimensional lid‑driven cavity flow. Experiments used a 1:1 depth‑to‑width cavity with span‑to‑width ratios of 3:1, 2:1, and 1:1, visualized with thymol blue and laser‑sheet rheoscopic techniques at Reynolds numbers 1,000–10,000. Results show that corner vortices at the end walls largely determine the downstream secondary eddy size, and that reducing the cavity span shrinks this eddy at the symmetry plane for Reynolds numbers above 2,000.
Experiments were conducted in a three-dimensional lid-driven cavity flow to study the effects of the end walls on the size of the downstream secondary eddy. The ratio of cavity depth to cavity width is 1:1. The span of the cavity was varied such that span-to-width ratios of 3:1, 2:1, and 1:1 were obtained. Flow visualization was accomplished by the thymol blue technique, and by rheoscopic liquid illuminated by laser-light sheets, for Reynolds numbers (based on lid speed and cavity width) between 1000 and 10,000. The results indicate that the corner vortices present at the end walls, in the region of the downstream secondary eddy, are a major influence on the size of this eddy. In addition, as the span of the cavity is reduced the size of the downstream secondary eddy at the symmetry plane becomes smaller with increasing Reynolds numbers, for Reynolds numbers greater than 2000.