Instrumentation : Flow Measurement

Flow is defined as the volumetric displacement of any substance with time. In fluid mechanics, the Reynolds number (Re) is a dimensionless quantity that is used to help predict similar flow patterns in different fluid flow situations.

Flow is classified din to three based on Reynolds number

1. Laminar flow (Re<2000)
   It happens with small pipes and low flow velocities.
   In laminar flow innermost parts flow the fastest, and the outer layer /cylinder touching the pipe does not move at all.
   Shear stress in a laminar flow depends only on viscosity - μ - and is independent of density - ρ.
2. Turbulent flow(Re>2000)
   It happened when flow rate is high with in larger pipes
   In turbulent flow vortices, eddies and wakes make the flow unpredictable.
   Shear stress in a turbulent flow is a function of density - ρ.
3. Transitional flow (2000<Re<4000)
   It is a mixture of laminar and turbulent flow, with turbulence in the center of the pipe, and laminar flow near the edges. Each fluid flows behave in different manners with respect to their frictional energy loss and have different equations to predict behaviour.

The video explains:

1. Type of flow meter to be used using Reynolds no 
2. Function and working of rotameter
3. Where do we use Rotameter