In this tutorial, we will perform an analysis of a propeller using Multiple Reference Frame (MRF) mechanism.
Before you begin, download the geometry file.
- Click Load Geometry button
- Select geometry file
- Click Open
After loading the geometry should appear in the 3D window.
You need to create a cylindrical boundary for the domain. For this purpose, you will create a cylindrical geometry for later use in the meshing process.
- Click Create Cylinder
- Click Properties if
cylinder_1properties are not displayed
- Double click on
cylinder_1and change name to
external. Press Enter to apply.
- Set origin of the cylinder.
- Set axis of the cylinder.
- Set length.
Refinement Area (I)
In order to better resolve the flow near the propeller you will create an area with higher mesh resolution. To do that you will copy most setting from the
- Click Options next to the
- In the drop-down menu select Duplicate option
- Click Properties if cylinder parameters are not displayed
- Double click and change the name to
- Set proper radius of the refinement geometry
Propeller Meshing Parameters
- Go to Hex Meshing panel
- Enable meshing on
- Enable boundary layers
- Set minimum mesh refinement on the geometry
- Set maximum mesh refinement
Refine Geometry Parameters
We want to create refinement in the area along the propeller induced flow.
- Enable meshing on external geometry
- Enable refinement on
- Increase refinement Level on
Base Mesh Definition
You want to create a mesh of only one blade of the propeller. For this purpose you will create base mesh covering only one fourth of the geometry.
- Move to the Base tab
- Define base mesh Minimum extend
- Define base mesh Maximum extend
- Define Division along each axis
- Select name for the
- Select name for the
- Select name for the first side of the boundary interface
- Select name for the second side of the boundary interface
Define Material Point
- Go to Point tab
- Set location outside the propeller geometry
Start Meshing Process
- Go to
- Start the meshing process with Mesh button
After a few minutes of meshing the mesh should be loaded.
For the simulation of marine propeller you will use steady-state incompressible
- Go to Setup panel
- Select the solver
- Go to Turbulence panel
Realizable k-εturbulence model
- Go to Transport Properties panel
- Enter the kinematic viscosity of water
Note that you do not have to define density. This is because equations for incompressible flows use kinematic pressure which is pressure divided by density. This way density does not explicitly appear in the equations. You have to remember to later multiply resulting pressure and forces by density to get the physical results.
Cell Zones for MRF
We want to create a cell zone where we want to solve equations in rotating reference frame. This way we will be able to model a rotating propeller without rotating the mesh.
- Go to Mesh Tools panel
- Click Options
- In the menu click
Add Cell Zones
- Click Create Cell Zones
Rotating Reference Frame
- Go to Cell Zones panel
- Enable rotating frame for external zone
- Define Axis of the propeller
- Make all boundaries except
Boundary Interface (I)
Before defining the boundary conditions we have to set proper boundary types and create interfaces.
- Go to Mesh panel
- Change boundary type of
- Hold Ctrl key and select
- Click Create Arbitrary Interface between
- Expand the interface properties
- Change type to
- Define Axis
Boundary Conditions – external
- Go to Boundary Conditions panel
- Select Turbulence tab
- Set Turbulence Intensity to 1%
- Click Copy Boundary Conditions
Boundary Conditions – inlet
We want to copy settings from
inletboundary to copy to
- Click Copy
Boundary Conditions – outlet
We want to monitor solution progress by observing force coefficients.
- Go to Monitors panel
- Select Forces tab
- Expand monitored boundaries list
- Go to Run panel
- Define number of iterations
- Start calculation
End time in steady state simulation (such as this one) represents the number of iterations.
End time in transient simulation is expressed in seconds.
Observe whether the solution converges by observing stabilization of forces on the propeller.
Calculate Additional Fields
When simulation is finished we want to calculate additional solution field to be used for postprocessing.
- Go to Calculate panel
- Calculate the field
- Go to Postprocessing panel
- Run ParaView
- Select last result set
- Load results into ParaView
- Specify contour range
- Create new contour
We want to show contours on the full propeller.
- Press Ctrl + Space keys to open search window
- Start typing the word
- Press Enter
- Define 90 degree rotation about the
- Create transformation
Repeat steps 1 to 6 for rotation angles 180 and 270.
Make sure the contour and all its transformations are visible.
In the 3D view the contour of full propeller should appear.
This concludes the tutorial.