Laminar flow

Laminar flow is one of three types of flow in fluid dynamics (laminar, turbulent and transitional) which is characterised by the layers of the fluid running in straight lines parallel to one another and the sides of the pipe, e.g. like a pack of cards. There is no intermixing between layers and the flow is seen as very regular.

Determining type of flow
Whether the flow of a fluid is laminar, turbulent or transitional can be calculated by finding its Reynolds number, Re, which is also a dimensionless number in that it has no units.


 * $$ \mathrm{Re} = {{\rho {ud} } \over {\mu}}$$

where:
 * $$\rho$$ = density
 * $${u}$$ = mean velocity
 * $${d}$$ = diameter
 * $$\mu$$ = viscosity