An Ohm’s law analogy for the effective diffusivity of composite media

• An Ohm’s law analogy for effective diffusivity in composite media is studied.
• Particles are seen as charges moving in an electrical resistance arrangement.
• Good agreement with Brownian particle simulations was found.

The aim of this work is to obtain an equation for the effective diffusivity of permeable composite media based on an analogy with Ohm’s law of electricity. Here, particles are transported across a composite medium, which is seen as an arrangement of series and parallel resistances. Comparison with simulations of Brownian particles traveling through the successive walls of the medium showed good agreement for moderate inclusion-to-continuous medium diffusivity ratio.