computer exercise 1the cavity case • create a folder cfd_labof in your local directory • copy...
TRANSCRIPT
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Computer exercise 1
MVK150: Applied CFD
Aurélia VallierHolger Grosshans
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How to get OpenFOAM
Unix/Linux
www.opencfd.co.uk
MS Windows (used in this lab)
http://sourceforge.net/projects/openfoam-mswin/
DOCUMENTATION (linux version)http://foam.sourceforge.net/doc/Guides-a4/UserGuide.pdf
http://www.opencfd.co.uk/http://sourceforge.net/projects/openfoam-mswin/http://sourceforge.net/projects/openfoam-mswin/http://sourceforge.net/projects/openfoam-mswin/
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Tree structure
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Tree structure
• OpenFOAM is a C++ library of applications
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Tree structure
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Tree structure
Input files for solving equationse.g. discretization schemes, used solver, timestep, …
Input files for the physical properties-> blockMeshDict = Input file for creating the meshFiles which define the mesh. Created by blockMeshDict
Initial conditions input files in 0. Results created in other folders
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The cavity case
• Create a folder CFD_labOF in your local directory
• Copy the cavity case
C:\win32app\cfd\OpenFOAM-1.5\tutorials\icoFoam\cavity
in this folder.
• Open OpenFOAM Designer and do File -> OpenCase to open your cavity case
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OpenFOAM Designer
Input files for the caseEditor for the input files
OpenFOAM applications
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Create the Mesh
• Look into the constant/polyMesh folder
• Do MeshUtilities -> Generation -> blockMesh -> start
• Look into the constant/polyMesh folder to see that the mesh was created
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Look at the mesh in Paraview
• Create an empty file cavity/cavity.OpenFOAM in OpenFOAM Designer (File-> New)
• Open paraview
• Add the pluggins as instructed
• File -> Open and open the file cavity.OpenFOAM
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Look at the mesh in Paraview
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blockMeshDict
Coordinates of the vertices 0 to 7
Connect the verticesinto one block
The cells are hexagonal
Number of cells in directionx, y and z
The mesh is equidistantin each direction
Name of the boundaries(user defined)
Type of the boundaries- empty type for 2D case- wall type for a wall- patch type for the others.
Connect the verticesinto one patch
• Edit ’constant/polyMesh/blockMeshDict’ in OpenFOAM Designer
Scale
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New case : bend pipe
• Copy case ’cavity’ to new case ’pipe’
• Open case ’pipe’ in OpenFOAM Designer
• Edit ’constant/polyMesh/blockMeshDict’
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block0
block2
block1
v0
Plan z=0
Plan z=0.1
v1
v2
v7
v5
v3
v4
v6
v13
v15v14
v12
v11
v8
v10
v9
3 m(40 cells)
3 m (40 cells)
1 m
New case : bend pipe
inletvelocity Ux = 1m/s Pressure : zeroGradient
Outlet velocity: zeroGradientPressure: fixedValue
innerWallvelocity : 0pressure : zeroGradient
outerWallvelocity : 0pressure : zeroGradient
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blockMeshDict: curved edges
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New case : bend pipe
• Create the mesh with BlockMesh
• Create an empty file pipe/pipe.OpenFOAM in OpenFOAM Designer (File-> New)
• Check the mesh in ParaView
• Do not close paraview and go back to the OpenFOAM Designer window
• Define the initial and boundary conditions by editing 0/U and 0/p
• Run icoFoam : solver -> incompressible -> icoFoam
• Check the results in paraView : load the new time steps by clicking the box ’updateGUI’ and ’Apply’.
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Check the results in paraview
Load the internal meshand the boundaries
Load velocity and pressure
Show the last time step computed
Show the velocity field
Show the scale
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Check the results in paraviewCreate a slice view (Znormal, uncheck ’Show Plane’ and Apply)
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Check the results in paraviewSample the results over a line : - Highlight the file ’pipe.OpenFOAM’-Filters -> Alphabetical -> Plot over Line-Define the sampling line-Apply
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Check the results in paraview
Try with another sampling line