Figure 1.

(a) Values of ${\tilde{D}}_{\mathrm{eff}}$ obtained for spheroids with aspect ratios χ = 1, 4, 1/4, 1/8, and 1/16 by homogenization method, plotted as functions of obstacle volume density, V. The number of obstacles used in the computations is n = 2560. Dashed lines indicate average values. Inset: a semilog plot of the same data. The error bars are not shown if they are comparable to symbol sizes. (b) Collapse of ${\tilde{D}}_{\mathrm{eff}}$ for spheroids onto ${\tilde{D}}_{\mathrm{eff}}$ for spheres under rescaling of volume densities V → αV/α_sphere.