Laminar Pipe Flow with Fluent -...
Transcript of Laminar Pipe Flow with Fluent -...
Laminar Pipe Flow with Fluent
Fluent 14 Seminar
Laminar Pipe Flow
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Open ANSYS project file
Launch ANSYS
Workbench View and Setup
Ignore warnings messages, refresh and update project.
Update Setup
Launch Fluent
Use double precision and start application.
Launch Fluent
Use double precision and start application.
Fluent workbench
Check mesh
Mesh output should look like this:
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(1)
Verify mesh sizeOn the main toolbar, go to Mesh, Info, and Size:
You should see this output:
Zooming in
To zoom in the pipe, hold down the middle button of your mouse or touchpad and draw a rectangle from the upper left corner to the lower right. Release the button once
you have chosen the area you want to zoom, as shown above.
To zoom out you hold down the same button but draw the rectangle from the lower right corner to the upper left corner.
A closer look
After zooming in a couple of times you should be able to see the mesh.
General options
Choose Axisymmetric.
Fluid Properties
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Set above properties and choose Change/Create,and Close.
Boundary Conditions: Centerline
Set the centerline zone as Axis.
Boundary Conditions: Inlet
Choose inlet, and set type to velocityinlet. Then Edit as shown above to specify an inlet axial velocity of 1 m/s.
Outlet and Wall Conditions
Set the outlet of the pipe as Type pressure outlet, and the pipe wall as Type Wall.
Choose solution method
Monitors
Edit ResidualsPrint,Plot to set 1e6 tolerance on the Monitors Panel above.
Initialization
Use the standard initialization method, and verify that the axial velocity is Set to 1m/s. Then press Initialize.
Launch solver
Choose Run Calculation, set the Number of Iterations to 100 and press Calculate twice. A solution should be obtained in about 50 iterations.
Centerline velocity
Go to Results, choose XY Plot and Set up. On the Solution XY Plot panel above, set Velocity..., Axial Velocity on Y Axis Function, and on X Axis Function set
Direction Vector. On surfaces set centerline.
Centerline Velocity Plot
The plot shows that fully developed flow is reached in about 2 meters away from the inlet.
Homework
● Determine the entrance length as a function the Reynolds number. The entrance length is defined as the axial location in the tube where the velocity becomes fully developed.
● Plot the friction factor as a function of the Reynolds number.