Channel flow around a circle for medium Reynolds number (power law) 

Computational details


Short description and remarks


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Short description and remarks
The aim of this study is to demonstrate the influence of the power law model for the stress tensor with nonlinear viscosity nu(u), nu(u) = nu (1 + D(u))**(alpha), on the resulting flow behaviour (with norm D(u) of the deformation tensor). As could be expected for the performed parameters, an increase of the parameter `alpha' in the exponent leads locally to smaller viscosity values or to a larger Reynolds number. While for `alpha=0' (Newtonian!) the flow has a steady limit, the corresponding flow patterns are nonsteady for increasing `alpha'. We even performed calculations for values `alpha' greater than 1 (for 1.5 and 2) but due to the significantly decreasing viscosity parameter (locally!), the chosen grid might be too coarse to resolve accurately all smallscale phenomenons for these small viscosity values. The following diagrams show the resulting drag and lift coefficients in time. Hereby, we always applied the same evaluation procedure including the constant value nu only, neglecting the nonlinear viscosity parts in nu(u)! The performed values for `alpha' are 0, 0.5 and 1. As can be seen, the flow changes form steady flow (`alpha=0') to fully nonsteady behaviour (`alpha=0.5 or 1')




Visualization




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