transportprocess

Transport process, or transport phenomena, refers to the mechanisms by which momentum, energy, and mass move within and between physical systems. The field is interdisciplinary, spanning chemical, mechanical, civil, environmental engineering, physics, chemistry, and biology. It seeks to quantify and predict how gradients in velocity, temperature, or concentration, as well as body forces and phase changes, drive transport at scales from molecules to devices.

Momentum transfer is described by viscosity and fluid dynamics, with Newton's law and the Navier–Stokes equations governing momentum diffusion and advection. Energy transfer includes conduction (Fourier's law), convection, and radiation, governed by energy balance and heat transfer coefficients. Mass transfer involves diffusion (Fick's laws) and convection, described by concentration fields and mass flux. In many systems these processes are coupled, such as heat and mass transfer in drying or momentum and energy transfer in turbulent flows.

Governing framework comprises conservation laws for mass, momentum, and energy, together with constitutive relations that link fluxes to driving forces. Solutions rely on boundary and initial conditions and are analyzed using nondimensional numbers such as Reynolds (Re), Prandtl (Pr), Nusselt (Nu), Schmidt (Sc), Peclet (Pe), and Sherwood (Sh). Methods include analytical solutions for simple geometries and transient or steady-state numerical simulations using finite difference, finite volume, or finite element methods.

Applications span industrial design of heat exchangers, reactors, drying equipment, and filtration; environmental engineering for pollutant transport in air and water; biological contexts such as nutrient transport and blood flow; and materials processing including solidification, coating, and polymer transport.