Impact of fiber diameter polydispersity on the permeability of fibrous media

•Several extensions of Davies correlation to polydisperse fibrous media are reviewed.•Permeability of polymodal fiber media is computed with the lattice Boltzmann method.•Volume-to-surface-area equivalent diameter is best to scale permeability.•A correction parameter based on fiber distribution spread is also proposed.•Permeability data collapse onto a master curve with a single empirical parameter.