Pipe Flow Simulation in SolidWorks

Aim: Run a pipe flow simulation with different inlet Velocity.

For each of these cases do the following

• Place line probes at 95%, 90% and 85% of the pipe length.
• Compare the normalized velocity profile at each of these locations
• Normalize the velocity profile by the inlet velocity.

Theory:

Carrying out fluid flow simulations in a virtual environment is a better-suited approach. This allows the engineer to model the fluid’s behaviour at every stage in the process and accurately predict how it will react in an actual casting environment. In doing so, it greatly reduces the time it takes to create a working design, which can then be manufactured in the real world. Because of the work that has been done in the virtual world, the chances of this unit performing as expected are greatly increased and the overall cost of development is substantially reduced.

Types of flow:

• Laminar flow: Laminar flow is characterized by smooth streamlines and highly ordered motion. If the pipe is sufficiently long (relative to the entry length) then the entrance effects are negligible and therefore the flow is fully developed. Laminar flow occurs when the fluid flows in parallel layers without mixing. The velocity of the fluid is constant at any given moment. Since the flow is steady, there is no acceleration. The flow is laminar for cylindrical pipes when the Reynolds number is less than 2500.
• Turbulent flow: Turbulent flow is characterized by velocity fluctuations and highly disordered motion. Most flows encountered in practice are turbulent. Turbulent flow occurs when streamlines of the liquid are irregular and change over time. The paths of the fluid flow are also irregular and form tiny whirlpool regions. The flow is turbulent when the Reynolds number is greater than 4000. In practice, most flows in engineering are turbulent.

The geometry of pipe:

Length of Pipe: 1000 mm

Outer Diameter: 60 mm

inner Diameter: 58 mm

Boundary conditions:

(1): Inlet velocity:

• 0.00185 m/s when R=100
• 0.0185 m/s when R=1000
• 0.185 m/s when R=10,000

(2): Static pressure = 101325 Pa

Temperature = 293.2 K

(3): Wall type: Real wall

Fluid characteristics

• Fluid used: water
• Dynamic viscosity: 8.9×10−4Pa.s
• The density of water: 1000 kg/m−3

Reynolds equation:

`R= (rho*v*D)/mu`

where:

• R is the Reynolds number, which is unitless
• ρ is the fluid density in kilograms-per-cubic-meter (kg/m3)
• v is the velocity in meters-per-second (m/s)
• D is the diameter of the pipe in meters (m)
• μ is the viscosity of the fluid in Pascal-seconds (Pa⋅s)

Velocity at different Reynolds numbers:

1. R=100 ; V=0.00185 m/s
2. R=1000 ; V=0.0185 m/s
3. R=10,000 ; V=0.185 m/s

Results of Parametric Study:

Plots:

1. Re=100 , v=0.00185 m/s

CutPlot at 950mm

CutPlot at 900mm

CutPlot at 850mm

2. Re=1000 , v=0.0185 m/s

CutPlot at 950mm:

Velocity at 950mm:

CutPlot at 900mm:

+

Velocity at 900mm:

CutPlot at 850mm:

Velocity at 850mm:

Comparison:

3. Re=10000 , v=0.185 m/s

CutPlot at 950mm:

Velocity at 950 mm:

CutPlot at 900mm:

Velocity at 900 mm:

CutPlot at 850 mm:

Velocity at 850 mm:

Comparison of Velocities at Different Input Velocities (0.00185,0.0185,0.185) at probe 95% :

Conclusion:

Observing the above results we can say that by increasing the Reynolds number the flow pattern changes and it goes from laminar to turbulent flow.

By increasing the mesh size we can get very accurate results.