Biofluid dynamics is also an example of a biological fluid. Types of Fluids Fluids can be classified into four basic types. They are: An Ideal Fluid is a fluid that has no viscosity, means it will offer no resistance, pragmatically this type of fluid does not exist. It is incompressible in nature. Real fluids are compressible in nature. They offer some resistance and thus have viscosity. All Fluids existing are real fluids. A Newtonian Fluid is a fluid whose viscous shear stresses (acting between different layers of fluid and between the fluid layer and surface over which it is flowing) are directly
Knudsen flow Knudsen flow Knudsen flow describes the movement of fluids with a high Knudsen number, that is, where the characteristic length in the flow space is of the same or smaller order of magnitude as the mean free path. For a gas passing through small holes in a thin wall in the Knudsen-flow regime, the number of molecules that pass through a hole is proportional to the pressure of the gas and inversely proportional to its molecular mass. It is therefore possible to effect a partial separation of a mixture of gases if the components have different molecular masses. The technique