CFD - Pipe Flow Simulation

Internal Pipe Flow Simulation

Objective

To run computational fluid dynamics on a pipe of given dimensions and to study the Normalized Velocity profiles with Reynolds Numbers 100 ,1000 and 10,000 at 85% , 90% and 95% of the pipe length.

Procedure

Reynolds Number:

• ρ is the density of the fluid ( kg/m³)
• u is the velocity of the fluid with respect to the object (m/s)
• L is a characteristic linear dimension (m)
• μ is the dynamic viscosity of the fluid (Pa·s or N·s/m² or kg/m·s)
• ν is the kinematic viscosity of the fluid (m²/s).

Based on the various reynolds numbers the inlet velocity is calculated for each 100,1000 and 10000 RN.

While 100 an 1000 fall in the laminar flow category, 10000 clearly belong to a pure turbulent category.

A pipe of the following dimensions were modelled uing solidworks

• Radius of the pipe = 50 mm
• Length = 1000 mm
• Thickness = 5 mm

Flow simulation in solidworks is used to simulate an internal flow in the given pipe using water as the medium.

• Density of water = 1000 kg/m^3
• Dinematic Viscosity of water = 8.9 x 10^-4 Pa.s

Various line probes are setup at 85,90,95% of the length of the pipe

Flow simulaion is run after defining inlet, outlet and bundary conditions

Cut plots and XY graphs for velocity at the various line probes are generated

The Various Inlet velocities for respective reynold's number:

Reynolds Number	Inlet Velocity m/s
100	.0017853
1000	.017853
10000	.17853

Outlet condition

Static Pressure: 101325 Pa

Temperature: 293.2K

Boundary Condition

Real Wall

Post Processing Data Plots

Case 1 [ Reynold's Number = 100 ]

(85,90,95 % of the length plots from left to right)

Case 2 [ Reynold's Number = 1000 ]

(85,90,95 % of the length plots from left to right)

Case 3 [ Reynold's Number = 10000 ]

(85,90,95 % of the length plots from left to right)

Resulting Cut plots

Reynold's number 100,1000,10000 at 85% Length

Reynold's number 100,1000,10000 at 90% Length

Reynold's number 100,1000,10000 at 95% Length

Conclusion

It can be concluded that for the turbulent flow Reynold's Number 10,000 the velocity seems to have a well defined center than the ones undergoing laminar flow(100,1000) as the flow reaches closer to the outlet it is seen that the velocity profile is negligbly varying.