Heat flows through a medium by its temperature gradient, which is known as Fourier's law of heat transfer by conduction, fluid flows through a pipe by its pressure gradient, which is known as Newton's law of motion, mass diffuses through materials by its concentration gradient, which is known as Fick's law of diffusion, charge flows through conductors by its potential gradient, which is known as Ohm's law, and the magnetic flux flows through mediums by its magnetic potential according to a Faraday's law. So, we have different mathematical models for similar transport phenomena which can be unified into one identical mathematical model. According to the presented study, an innovative analysis is followed that shows how any flow in a medium is driven by the volumetric density gradient of such flow, and the proportionality constant is its diffusivity constant, which has the units “m 2 /s.” This new formulation of the transport models can be applied for any transport phenomenon, e.g. heat flow, charge flow, magnetic flux, diffusion of mass and momentum transfer, which consequently indicates a strong analogy between the different transport models. So, we have a unique mathematical model for all transport phenomena that can be generally applied but with the corresponding parameters of each field.
Abd-Elhady et al. (Thu,) studied this question.