Pipe Flow Simulation

OBJECTIVES

To run a pipe flow simulation with an inlet Reynolds number of 100,1000 and 10,000. And for each of these cases

1. Place line probes at 95%, 90% and 85% of the pipe length.

2. Compare the normalized velocity profile at each of these locations.

3. Normalize the velocity profile by the inlet velocity.

Reynolds number calculations

Pipe dimensions

• Length of the pipe = 1000 mm
• Diameter of the pipe = 40 mm
• Thickness of the pipe = 1 mm

Water is the working fluid. Inside surface roughness of the pipe is taken negligible.

From calculations we get velocities for different reynolds number as follows Substituing in the above given eqution

• The dynamic viscosity of water is 8.90 × 10−4 Pa. s [ N.s/m^2].
• The density of water is 1000 Kg/m^3.
• Inlet Diameter of the pipe is 0.038 m.
• Inlet Reynolds number of 100, 1,000 and 10,000 .

We get velocities 0.002225, 0.02225, 0.2225 [in m^2] respectively.

Boundary conditions are

• Pipe Inlet -velocity of water is given (above calculations)
• Pipe Outlet- static pressure 1 bar
• Pipe wall- taken as real wall

Placing line probes at 95%, 90% and 85% of the pipe length ,we get line probes at a distance of 950mm, 900 mm and 850 mm respectively from the inlet of the pipe.

Cut plots at 850mm, 900 mm and 950 mm respectively for reynolds number 100.

Cut plots at 850mm, 900 mm and 950 mm respectively for reynolds number 1000.

Cut plots at 850mm, 900 mm and 950 mm respectively for reynolds number 10000.

In the results below ,

• Design_point_1- is with respect to reynolds number 100.
• Design_point_2- is with respect to reynolds number 1,000.
• Design_point_3- is with respect to reynolds number 10,000.

The velocity profile by the inlet velocity in Line probe at 85% of the pipe length.

The velocity profile by the inlet velocity in Line probe at 90% of the pipe length.

The velocity profile by the inlet velocity in Line probe at 95% of the pipe length.

Comparing the normalized velocity profile at each line probes.

Thus with reynolds number 1000 and 10000 for the given pipe dimensions with water as the working fluid ,the flow at the respective distances as seen from the cut plots is turbulent. For reynold number 100 the flow is laminar and turbulent at the center.

Reference

• google website
• project skill lync