Mechanisms for generating coherent packets of hairpin vortices in channel flow. (English) Zbl 0946.76030

From the text: The evolution of a single hairpin vortex-like structure in the mean turbulent field of a low-Reynolds-number channel flow is studied by direct numerical simulation. First, we discuss the extraction of the initial structure using stochastic estimation methodology, and give a brief discussion of the numerical simulation and the vortex identification methodology. Then we examine the development of the initial structure into a hairpin packet. The growth and threshold behaviour for the autoregeneration process are discussed, followed by comparison of the computed vortical structure with the experimental measurements. The next topic is the generation of additional quasi-streamwise vortices and the convective velocity of the hairpin packet. Finally, we address the effect of asymmetry on the evolution of hairpin structures.


76F10 Shear flows and turbulence
76D05 Navier-Stokes equations for incompressible viscous fluids
76M20 Finite difference methods applied to problems in fluid mechanics
76F65 Direct numerical and large eddy simulation of turbulence
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