A Volumetric Approach to Wake Reduction: Design, Optimization, and Experimental Verification

Figure 2

Monte Carlo sampling of the 8-dimensional functional space of permeability distributions (described by the coefficients in (2)) and its projection onto the wake-drag plane. Evaluation points are collected in scatter plots illustrating the boundaries of the wake-drag manifold for (a) Reynolds number (Re) = 20 and (b) Re = 100. For the wake norm, the dimensionless domain-wide wake (DWW) figure is used; see (8) for the definition of DWW. The drag force indicated along the abscissa is normalized by the Stokes drag of a solid sphere of radius . The shaded rectangle on each plot illustrates the maximum wake and drag possible from a solid sphere of radius . The solid black curve shows DWW and drag for various solid spheres of smaller radii. Note that the manifold quickly grows in vertical and horizontal dimensions with an increasing Reynolds number.

(a) Re = 20

(b) Re = 100