Effects of Turbulence Manipulation in Skimming Flows: An Experimental Study

Current expertise in air-water flow properties in turbulent flows is limited to low to moderate Reynolds numbers and a few types of surfaces (roughness). Highly turbulent air-water flows cascading down a large-size stepped spillway model were systematically investigated with a 22o slope. Several stepped configurations were tested and turbulence manipulation was conducted to enhance interactions between skimming flows and cavity recirculating regions. Systematic experiments were performed with 3 new configurations to complement an initial study [6] with another three configurations. Turbulence modifiers (vanes or longitudinal ribs) were observed to have a strong influence on the air-water flow properties, with wakes or low-speed streaks observed above each vane.

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