the liquid particles at different sections have different velocities
Reynold's number
The important dimensionless numbers in fluid mechanics are
1. Reynold’s number
2. Froude’s number
3. Weber’s number
4. Euler’s number
5. Mach’s number or Cauchy’s number
Reynold’s number: Reynold’s number is the ratio of inertia force to the viscous force.
Froude’s number: Froude’s number is the ratio of inertia force to the gravity force.
Weber’s number: Weber’s number is the ratio of inertia force to the surface tension force.
Euler’s number: Euler’s number is the ratio of inertia force to the pressure force.
Mach’s number or Cauchy’s number: Mach’s number or Cauchy’s number is the ratio of inertia force to the elastic force.
one
critical velocity
The velocity at which the flow changes from the laminar flow to the turbulent flow, is called critical velocity. It is of two types, i.e., lower critical velocity and higher critical velocity.
The velocity at which the laminar flow stops, is known as lower critical velocity, while the velocity at which the turbulent flow starts, is known as higher critical velocity.
