Fluid Mechanics...

For Flow to be Laminar

1) if Reynold’s number is less than 1000 for flow between parallel plates

2) if Reynold’s number is less than 500 for flow in open channel.

3) if Reynold’s number is less than 1, for flow through soil

For the laminar flow through a circular pipe the ratio of maximum velocity to average velocity is

Turbulent flow occurs in a pipe of diameter 130 mm which carries water. The velocities at the pipe centre and 35 mm from centre are 2.5 m/s and 1.5 m/s respectively. The shear stress at the wall of the pipe is

How much diameter (mm) of circular pipe is required so that the pressure drop over the length of 500m in a circular pipe will remain 70m. An oil of viscosity 0.2 Ns/m² and relative density 0.85 is flowing through a circular pipe. The rate of flow through the pipe is 4 liters/sec. Assume the Reynold’s number for the flow to be less than 2000.

A pipe of 3 km length carries water with a velocity of flow is 1.2 m/s and at a constant pressure of 100 kPa. Due to maintenance purposes the water supply is required to be shut down for a small period.  In order to do that the repairing worker closes the valve in just 4 seconds. What would be final pressure developed in the pipe (in kN/m², up to two decimal places) considering the water hammer effect? Assume that the bulk modulus of water is 2 × 10⁹ N/m² and density of water as 1000 kg/m³.