Table 3.

Predictive models for permeability calculation in 3D fibril networks

Author	Correlation	Comment
Davies [50]	$k/r_{\mathrm{f}}^2={[16(1-\phi ){}^{1.5}(1+56(1-\phi ){}^3)]}^{-1}$	$r_{\mathrm{f}}$: Fibril radius $\phi$: Porosity
Spielman and Goren [51]	$1/3+5/6[\sqrt{k}{K}_1(r_{\mathrm{f}}/\sqrt{k})/r_{\mathrm{f}}{K}_0(r_{\mathrm{f}}/\sqrt{k})]=1/4(1-\phi )$	$r_{\mathrm{f}}$: Fibril radius $\phi$: Porosity $K_{\mathrm{p}}$: Modified Bessel function of the second kind with order p
Jackson and James [52]	$k/r_{\mathrm{f}}^2=(3/20(1-\phi ))(-\ln (1-\phi )-0.931)$	$r_{\mathrm{f}}$: Fibril radius $\phi$: Porosity
Tomadakis and Robertson [18]	$k/r_{\mathrm{f}}^2=(\phi /8\ln {}^2\phi )((\phi -{\phi }_{\mathrm{p}}){}^{\alpha +2}/(1-{\phi }_{\mathrm{p}}){}^{\alpha }{[(\alpha +1)\phi -{\phi }_{\mathrm{p}}]}^2)$	$r_{\mathrm{f}}$: Fibril radius $\phi$: Porosity ${\phi }_{\mathrm{p}}$: Percolation threshold (0.037 for 3D) $\alpha$: Constant (0.661 for 3D)