Transport Phenomenon

Various mechanisms by which particles or quantities move from one place to another. Three common examples of transport phenomena are diffusionMovement of particles from higher chemical potential to lower chemical potential (chemical potential can in most cases of diffusion be represented by a change in concentration). Diffusion, the spontaneous spreading of matter (particles), heat, or momentum, is one type of transport phenomena. Because diffusion is thermally activated, coefficients for diffusion Click on Term to Read More,convectionTransfer of heat energy by moving material. Temperatures increases with depth in planetary objects. Deep hot less-dense material physically rises and cools, releasing heat and becoming denser. The now cooler denser material sinks back into deeper regions, where it will be reheated and rise again. Convection is an important mechanism Click on Term to Read More, and radiation. There are three main types of transport phenomena: heat transfer, mass transfer, and fluid dynamics (or momentum transfer). An important principle in the study of transport phenomena is analogy between phenomena. For example, mass, energy, and momentum can all be transported by diffusion. The spreading and dissipation of an odor in air is an example of mass diffusion. Heat conductionFlow of internal energy (heat) from a region of higher temperature to one of lower temperature by the interaction of the adjacent particles (atoms, molecules, ions, electrons, etc.) in the intervening space. The factors that affect the rate of heat transfer by conduction are the temperature difference (ΔT), length (l), Click on Term to Read More in a solid material is an example of heat diffusion. The drag experienced by a rain drop as it falls in the atmosphere is an example of momentum diffusion (the rain drop loses momentum to the surrounding air through viscous stresses and
decelerates).