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Direct numerical simulation of a fully developed turbulent flow over a wavy wall. (English) Zbl 0920.76066
Summary: Turbulent flow over a sinusoidal solid wavy surface is investigated by a direct numerical simulation using a spectral element technique. The train of waves has an amplitude to wavelength ratio of 0.05. For the flow conditions (\(\text{Re}= hU_b/2\nu= 3460\)) considered, adverse pressure gradients are large enough to cause flow separation. Numerical results compare favorably with measurements. Instantaneous flow fields show a large variation of the flow pattern in the spanwise direction in the separated bubble at a given time. A surprising result is the discovery of occasional velocity bursts which originate in the separated region and extend over large distances away from the wavy wall. Turbulence in this region is very different from that near a flat wall in that it is associated with a shear layer which is formed by flow separation.

76M25 Other numerical methods (fluid mechanics) (MSC2010)
76F10 Shear flows and turbulence
65M70 Spectral, collocation and related methods for initial value and initial-boundary value problems involving PDEs
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