Flows over Two-Dimensional Backward — Facing Steps
This paper presents experimental results of the mean and turbulence velocity fields for the flow over two-dimensional backward-facing steps in ducts and open channels. The dependence of the flow on the upstream Reynolds number and on the expansion ratio is investigated. Where possible, comparisons have been drawn between these results and those from other researchers.
The experiments were carried out in water flows in nominally two-dimensional test sections. Velocity measurements were made with a single component, laser-Doppler anemometer operated in forward scatter and employing a transient recorder and digital computer for signal processing. Measurements were obtained for Reynolds numbers (based on step height) in the range 2 × 103 < ReH < 2 × 104, and for expansion ratios in the range 1.06 < ER < 3.0.
KeywordsReynolds Number Shear Layer Expansion Ratio Step Height Separate Shear Layer
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