Laminar Flow Fluid Flow Review
In fluid dynamics , laminar flow (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption between the layers. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids.In laminar flow, the motion of the particles of the fluid is very orderly with all particles moving in straight lines parallel to the pipe walls. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection .
When a fluid is flowing through a closed channel such as a pipe or between two flat plates, either of two types of flow may occur depending on the velocity of the fluid: laminar flow or turbulent flow . Laminar flow tends to occur at lower velocities, below a threshold at which it becomes turbulent. Turbulent flow is a less orderly flow regime that is characterised by eddies or small packets of fluid particles which result in lateral mixing. In non-scientific terms, laminar flow is smooth while turbulent flow is rough .
Laminar flow is also referred to as streamline or viscous flow.
These terms are descriptive of the flow
because, in laminar flow, (1) layers of water flowing over one another at
different speeds with virtually no mixing
between layers, (2) fluid particles move in definite and observable
paths or streamlines, and (3) the flow is characteristic of viscous (thick)
fluid or is one in which viscosity of the
fluid plays a significant part.