Transport phenomenon

All of the transport phenomena are interrelated to some extent. It is worthy to spend some time in discussing the similarities among the transport phenomenon. We have already discussed some of the similarities of the transport phenomenon earlier, here we will add some of the essential concepts.

  1. Necessity is proportional to Diffusion
  • The diffusion rate of is quite high. So oxygen taken at once can remain in the blood for a very short time. Then body cell absorbs it all. And within a very short time, O2 supply is needed again.
  • Water diffuses into the blood at the medium rate and absorbed by the cell after a certain period. So, further supply must not as fast as oxygen.
  • Body cell cannot take solid element. Food at first reacts with enzyme and acid and the nutrition turns into liquid form after several processes to mix up with blood. Then cell takes the nutrition from the blood. Thus the body needs a long time to diffuse food (almost a week).
  1. Availability is proportional to Diffusion

In-universe material’s availability is in order of diffusion rate. A material having more diffusion rate is more available in surroundings.


  • is everywhere available in the surrounding.
  • Water is available in sufficient amount and low-cost also.
  • But food is not as available as water and air.

Thus, almost every person has the nutritional deficiency.



Transport Phenomena deals with the movement of different physical quantities in any chemical or mechanical process.

Transport phenomena can be classified into three types:

  1. Mass
  2. Heat and
  3. Momentum.


There are also 2 types of transport:

  • Volume transport ( follows Darcy’s law)
  • Electric transport (follows Ohm’s law)


Mass Transfer deals with the transfer of mass.

Example: mixing of sugar in water, mixing of oxygen with blood


Heat Transfer deals with the transfer of heat. Heat is just another way to say energy. Typical methods of Heat Transfer are:

  1. Conduction, 2. Convection and 3. Radiation

Example: Cooling of tea, heating of water in a stove.


Fluid Mechanics deals with the transfer of momentum in a fluid.

Example: On a molecular scale that means that the molecules banging into each other transfer their momentum to other molecules. On a larger scale, these molecules banging into each other determine how the fluid is going to flow that is, if it will just flow smoothly (or ‘laminar’), or if it will be rough (or ‘turbulent’).

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