Getting started with Flow Simulation in SolidWorks

Objective: To run a pipe simulation with the given inlet Reynolds number.

Problem Statement:

Run a pipe flow simulation with an inlet Reynolds number of 100,1000 and 10,000.

For each of these cases do the following

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.

Theory: Fluid flow in a pipe encounters frictional resistance due to the internal roughness (e) of the pipe wall, which can create local eddy currents within the fluid. Calculation of the Reynolds Number helps to determine if the flow in the pipe is Laminar Flow or Turbulent Flow.

Pipes that have a smooth wall such as glass, copper, brass, and polyethylene cause less frictional resistance, and hence they produce a smaller frictional loss than those pipes with a greater internal roughness, such as concrete, cast iron, and steel.

The velocity profile of fluid flow in a pipe shows that the fluid at the center of the stream moves more quickly than the fluid flow towards the edge of the stream. Therefore friction occurs between layers within the fluid.

Fluids with a high viscosity flow more slowly and generally not produce eddy currents, thus the internal roughness of the pipe has little or no effect on the frictional resistance to flow in the pipe. This condition is known as laminar flow.

Formulae:

L = 1 m

ρ = 1000 kg/m³

D = 0.04 m

η = 8.90 × 10⁻⁴ Pa·s

V = (Re*η)/(ρ*D) m/s

Where for,

Case 1: Re =100

V = (100*8.90 × 10⁻⁴)/(1000*0.04)

V = 0.0022 m/s

Case 2: Re = 1000

V = (1000*8.90 × 10⁻⁴)/(1000*0.04)

V = 0.022 m/s

Case 3: Re = 10000

V = (10000*8.90 × 10⁻⁴)/(1000*0.04)

V = 0.22 m/s

Case Setup:

The pipe is made from the above given dimensions and then there are line probes at 85%,90%,95%.

The following boundary conditions such as inlet and static pressure are given to the appropriate lids and the real wall for the outer face of the pipe.

Then these mesh conditions are applied to the pipe. Then the necessary cut plots are created along with their plots

Procedure:

1. Create the pipe with the dimensions mentioned.
2. Then create the shell with a diameter of 0.001.
3. Add line probes at 85%,90%,95%.
4. Then move to the flow simulation add-in.
5. Create lids at both the open ends of the pipe.
6. Create a new flow simulation project and add the project name.
7. Apply the boundary conditions as shown above.
8. Then adjust the mesh condition as mentioned.
9. Create cut plots and other necessary plots.
10. Then run the program. After the results arrive modify the transparency to 0.5 and click ok.
11. Then right-click on the plots and select show option.

Results:

Case 1: Re=100

a) Line Probe at 85%

b) Line Probe at 90%

c) Line Probe at 95%

For all the three cases we can observe from the heat map that as the flow of the fluid starts to increase and move forward from 85% to 95% the amount of red area (max velocity) tends to decrease because of the increase in the friction losses as the fluid continues to flow.

The same can be concluded from the velocity plots as well. The velocity at the center remains to be the highest compared to the outermost diameter as the velocity decreases from the inner diameter to the outer diameter.

Case 2: Re=1000

a) Line Probe at 85%

For all the three cases we can observe from the heat map that as the flow of the fluid starts to increase and move forward from 85% to 95% the amount of red area (max velocity) tends to decrease because of the increase in the friction losses as the fluid continues to flow.

The same can be concluded from the velocity plots as well. The velocity at the center remains to be the highest compared to the outermost diameter as the velocity decreases from the inner diameter to the outer diameter.

b) Line Probe at 90%

For all the three cases we can observe from the heat map that as the flow of the fluid starts to increase and move forward from 85% to 95% the amount of red area (max velocity) tends to decrease because of the increase in the friction losses as the fluid continues to flow.

The same can be concluded from the velocity plots as well. The velocity at the center remains to be the highest compared to the outermost diameter as the velocity decreases from the inner diameter to the outer diameter.

c) Line Probe at 95%

For all the three cases we can observe from the heat map that as the flow of the fluid starts to increase and move forward from 85% to 95% the amount of red area (max velocity) tends to decrease because of the increase in the friction losses as the fluid continues to flow.

The same can be concluded from the velocity plots as well. The velocity at the center remains to be the highest compared to the outermost diameter as the velocity decreases from the inner diameter to the outer diameter.

Case 3: Re=10000

a) Line Probe at 85%

b) Line Probe at 90%

c) Line Probe at 95%

For all the three cases we can observe from the heat map that as the flow of the fluid starts to increase and move forward from 85% to 95% the amount of red area (max velocity) tends to decrease because of the increase in the friction losses as the fluid continues to flow.

The same can be concluded from the velocity plots as well. The velocity at the center remains to be the highest compared to the outermost diameter as the velocity decreases from the inner diameter to the outer diameter.

Conclusion:

The flow simulation was successfully run on the given conditions and the desired plots were achieved.

References:

https://www.pipeflow.com/pipe-pressure-drop-calculations/reynolds-numbers