Flow Simulation Using Solidworks

Pipe Flow Simulation Using SolidWorks us Flow Simulation.

Introduction

The purpose of this study is to simulate flow in pipe utilizing SolidWorks software.SolidWorks add-ins enable you to simulate the flow of liquids and gases and efficiently analyze the effects of fluid flow.

The motion of a fluid is usually very complex. The observed fluid flow behavior becomes much more understandable after defining the flow into laminar or turbulent. Hence conducting a parametric study will give me basic understanding motion of the fluid(velocity, pressure, etc)

Objectives

In this study we will be looking to:

1. Model a pipe system using SolidWorks.
2. Placing line probes at 95%, 90% and 85% of the pipe length and compare the velocity at each location for the three cases.
3. Simulate flow at different Reynold's number(i.e. 100,1000, & 10000) and analyze the fluid flow in pipes using the SolidWorks Flow Simulation add-in.

Basic understanding of 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 Reynolds number is less than 2300.

Fig 1 Laminar flow

• 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 Reynolds number is greater than 4000. In practice, most flows in engineering are turbulent.

Fig 2 Turbulent flow

Method Followed

Initial Condition

• Diameter Of the Pipe: 0.020m
• Length Of the Pipe: 0.600m
• Shell Thickness: 0.001m
• Fluid Medium: Air
• Reynolds number 100,1000 and 10,000.
• At the outlet, pressure and temperature are 101325 Pa & 293.2 K( 20ºC) respectively.
• All Dimensions are in meters

Calculations

We have to Calculate the initial velocity for a given Reynolds number to simulate a fluid flow in a pipe.

Reynolds number

Reynolds number can reveal whether the flow is laminar or turbulent. The transition from laminar to turbulent flow depends on the surface roughness, flow velocity, geometry, surface temperature, and type of fluid, among others.

Properties of air at atmospheric pressure:

From the Table above, the kinematic viscosity of air at 20ºC is 15.06 m²/s.

Hence, inlet velocity can be calculated by

.....(m/s)

After Calculation the Three different velocities for different Reynolds number are,

Procedure:

1. Create a new part model. And make a circle of diameter 20mm and extrude it to 600mm, making a cylindrical pipe.
2. Select shell, then select both faces of the cylinder and give 1mm as thickness. Hence making a pipe of 1mm thickness.
3. Create new sketch along the length of the pipe and create a vertical line at 85% of the length (i.e.510mm from inlet). Similarly for 90% and 95% of the length.
4. Go to Flow Simulation, and select Crete lid command and select end faces of the pipe to make a closed volume for fluid flow simulation.
5. Click on the New project in flow simulation toolbar.
6. Right click on input data on flow simulation tree, and select general setting.
7. In Fluids, select Air as project fluid, flow type as Laminar and turbulent and in Initial Conditions pressure as 101325Pa, Temperature as 293.2K and velocity as 0m/s.
8. Right click on boundary conditions and select insert boundary conditions. The first boundary condition for out-flow, select static pressure of 101325Pa and Face of the lid (Face@lid) of one end of the pipe. The second boundary condition for inflow and select the inlet velocity of 0.0753m/s on another end of the pipe. The last boundary condition for Wall is the Real wall and select the inner wall of the pipe.
9. Creating a XY plot. Right click on XY plot for velocity in normal to the plane direction (Z-direction) and select insert then select the 85% line sketch. Similarly, make XY plot for 90% and 95%. Similarly, insert a new XY plot for comparing the three line probe for velocity.
10. Right click on Global Mesh and select edit definitions, change mesh manually, in X-direction 20, in Y-direction 20, in Z-direction 100.
11. Right click on Project(1) and select new parametric study.
12. Then select inlet velocity in input variables tab, select all XY plots.
13. Go to scenario tab and select Design point 1 and copy - paste it two more times.
14. Change inlet velocity in design point 2 and 3 with 2.28E-02 and 2.28E01m/s.
15. Run.

Output

Case 1: When Reynold's number is 100.

Cut Plot:

XY Plot:

Velocity Comparison For three line Probe(0.0753m/s).

Case 2: When Reynold's number is 1000.

Cut Plot:

XY Plot:

Velocity Comparison For three line Probe(0.753m/s).

Case 3: When Reynold's number is 10000.

Cut Plot:

XY Plot:

Velocity Comparison For three line Probe(7.53m/s).

Conclusion:

With the given values and conditions, the flow simulation of a pipe is successfully completed and the results are displayed.