1. Workshop 5 Centrifugal Pump
Introductory FLUENT Training

2. Introduction
The Purpose of the tutorial is to model fluid flow in a centrifugal pump, which involves the use of rotation model.
Problem consists of a five blade centrifugal pump operating at 2160 rpm. The working fluid is water and flow is assumed to be steady and incompressible.
Due to rotational periodicity a single blade passage will be modeled.

3. Starting Fluent in Workbench
Open the Workbench (Start > Programs > ANSYS 12.0 > ANSYS Workbench)
Drag FLUENT into the project schematic
Change the name to Duct
Double click on Setup
Choose 3D and Double Precision under Options and retain the other default settings

4. Import Mesh
This starts a new Fluent session and the first step is to import the mesh that has already been created:
Under the File menu select Import> Mesh
Select the file tfa-pump-lite-cav-300k.msh and click OK to import the mesh
After reading the mesh, check the grid using Mesh>Check option
or by using Check under Problem Setup>General

5. Setting up the Models
Select Pressure Based, Steady state solver Problem Setup>General>Solver
Specify Turbulence model
Problem Setup > Models > Viscous
Double click and Select k-epsilon (2 eqn) under Model and Realizable under k-epsilon model and retain the default settings for the other parameters
Make sure that the Energy Equation is disabled
Problem Setup > Models> Energy

6. Materials Define the materials. Problem Setup > Materials
Click on air to open Create/Edit Materials panel
Change Name to water and Density and Viscosity to 1000 kg/m3 and kg/(m-s) respectively
Click on Change/Create
Click on Yes, on being asked for Change/Create mixture and Overwrite air

7. Fluid Zone Conditions
Under Problem Setup >Cell Zone Conditions (operating conditions are also in BC panel) double click on Fluid
Select Material Name : water
Select Motion Type: Moving Reference Frame
Specify Rotational Velocity : 2160 rpm
Click on OK

8. Operating Conditions
Under Problem Setup >Cell Zone Conditions (operating conditions are also in BC panel)
Click on Operating Conditions… and set the Operating Pressure (Pascal) to 0

9. Boundary Conditions Under Problem Setup > Boundary Conditions
Select inlet under Zone and choose velocity-inlet from the drop down menu under Type
Now double click on inlet under Zone
Input all the parameters in Momentum tab as shown below

10. Boundary Conditions Under Problem Setup > Boundary Conditions
Select outlet under Zone and choose pressure-outlet from the drop down menu under Type
Now double click on outlet under Zone
Input all the parameters in Momentum tab as shown below

11. Boundary Conditions Under Problem Setup > Boundary Conditions
Select blade under Zone and choose wall from the drop down menu under Type
Now double click on blade under Zone
Input all the parameters in Momentum tab as shown below

12. Boundary Conditions Under Problem Setup > Boundary Conditions
Select hub under Zone and choose wall from the drop down menu under Type
Now double click on hub under Zone
Input all the parameters in Momentum tab as shown below

13. Boundary Conditions Under Problem Setup > Boundary Conditions
Select shroud under Zone and choose wall from the drop down menu under Type
Now double click on shroud under Zone
Input all the parameters in Momentum tab as shown below

14. Boundary Conditions Under Problem Setup > Boundary Conditions
Select hub-outer under Zone and choose wall from the drop down menu under Type
Now double click on hub-outer under Zone
Input all the parameters in Momentum tab as shown below

15. Boundary Conditions Under Problem Setup > Boundary Conditions
Select inlet-shroud under Zone and choose wall from the drop down menu under Type
Now double click on inlet-shroud under Zone
Input all the parameters in Momentum tab as shown below

16. Boundary Conditions Under Problem Setup > Boundary Conditions
Select shroud-outer under Zone and choose wall from the drop down menu under Type
Now double click on shroud-outer under Zone
Input all the parameters in Momentum tab as shown below

17. Boundary Conditions Under Problem Setup > Boundary Conditions
Select periodic.10 under Zone and choose periodic from the drop down menu under Type
Now double click on periodic.10 under Zone
Select Periodic Type: Rotational
Click on OK
Now double click on periodic.11 under Zone

18. Monitors Residual Monitoring Solution > Monitors
Double click on Residuals (By default it is on)
Enable Plot under Options.
Specify Absolute Criteria for continuity: 1e-5

19. Monitors Surface Monitors
Monitor points are used to monitor quantities of interest during the solution. They should be used to help judge convergence. In this case you will monitor the Total Pressure and Static Pressure at inlet.
Solution > Monitors > Surface Monitors
Click on Create to create a new surface monitor
Type ‘total_pressure’ under Name
Enable Printing, Plotting and writing of monitors by marking check boxes under Options
Select Mass-Weighted Average from the drop-down menu under Report Type
Select Pressure as the Field Variable and select Total Pressure under Pressure variable

20. Monitors Select inlet as the Surfaces to be monitored
Click on OK to create the monitor and to close the panel

21. Monitors Solution > Monitors > Surface Monitors
Click on Create to create a new surface monitor
Type ‘static_pressure’ under Name
Enable Printing, Plotting and writing of monitors by marking check boxes under Options
Select Area-Weighted Average from the drop-down menu under Report Type
Select Pressure as the Field Variable and select Static Pressure under Pressure variable
Select inlet as the Surfaces to be monitored
Click on OK to create the monitor and to close the panel

22. Initialization
Before starting the calculations we must initialize the flow field in the entire domain
Solution > Monitors > Solution Initialization
Initializing the flow field with near steady state conditions will result in faster convergence
Select Compute from: inlet
Click on Initialize to initialize the solution

23. Run Calculations
The solution process can be started in the following manner
Solution >Run Calculation
Enter 1000 for Number of Iterations and click on Calculate
During the iteration process, both the residue plot and monitor plots will be shown in different windows. If the velocity monitor is not changing further we can stop the iterations. You may specify more number of iterations if the monitors are still changing significantly.
The magnitude of change of a monitor per iteration can be observed from the console (enabled by clicking on Print to Console while creating the monitor)
Note: Iterations can be stopped in between, by pressing Ctrl+ C together in the Fluent’s console.

24. Higher Order Accurate Solution
Once first order run is converged (it takes 211 iterations)
Under Solution>Solution Methods setup the parameters as shown below
The solution process can be started in the following manner
Solution >Run Calculation
Enter 1000 for Number of Iterations and click on Calculate

25. Residuals

26. Write Case File
You can now save the project and proceed to write a case file for the solver:
To save the project, go to Project Page
File>Save as
To write the case files, go to FLUENT session
File>Export>Case..

27. Post Processing To Draw Contours of Static Pressure on blade
Display > Graphics and Animations
Double Click on Contours, a new window will pop up
Select Pressure under Contours of and Static Pressure below that
Select blade under Surfaces

28. Post Processing To Draw Contours of Static Pressure on hub
Display > Graphics and Animations
Double Click on Contours, a new window will pop up
Select Pressure under Contours of and Static Pressure below that
Select hub under Surfaces

29. Post Processing To Draw Contours of Static Pressure on shroud
Display > Graphics and Animations
Double Click on Contours, a new window will pop up
Select Pressure under Contours of and Static Pressure below that
Select shroud under Surfaces