Section Evaluate the use of cfMesh for the Francis-99 turbine. CFD with OpenSource Software Jethro Raymond Nagawkar Applied Mechanics/Fluid Dynamics, Chalmers University of Technology, Gothenburg, Sweden 2015-12-08 Jethro Raymond Nagawkar Openfoam presentation 2015-12-08 1 / 23
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Evaluate the use of cfMesh for the Francis-99 turbine. CFD ...hani/kurser/OS_CFD_2015/... · Francis-99 turbine. CFD with OpenSource Software ... Jethro Raymond Nagawkar Openfoam
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Section
Evaluate the use of cfMeshfor the
Francis-99 turbine.CFD with OpenSource Software
Jethro Raymond Nagawkar
Applied Mechanics/Fluid Dynamics,Chalmers University of Technology,
Gothenburg, Sweden
2015-12-08
Jethro Raymond Nagawkar Openfoam presentation 2015-12-08 1 / 23
Section
Subsection
Topics that will be covered
Introduction to cfMesh
Some options in cfMesh
Installing cfMesh
Meshing the 3 parts of the turbine
Problems during meshing
MergeMeshes
Setting up the Mixing Plane model
Implementing a boundary condition
Creating Zones
Running the simulations and results
Conclusions
Jethro Raymond Nagawkar Openfoam presentation 2015-12-08 2 / 23
Section
Subsection
Intorduction to cfMesh
Library for polyhedral mesh generation.
Uses and inside out method to generate the mesh.
Can generate 2D and 3D Cartesian meshes as well as 3D Tetrahedraland Polyhedral Meshes.
Uses both shared memory parallelization (SMP) and distributedmemory parallelization using MPI.
Can handle dirty geometry and is tolerable to small gaps, cracks andprotrusions.
Jethro Raymond Nagawkar Openfoam presentation 2015-12-08 3 / 23
Section
Subsection
Options in cfMesh
surfaceFile ”filename.stl/filename.fms”This is the name of the surface file you want to mesh along with itspath. The suggested formats of the files are .fms, .stl and .ftr.
maxCellSizeThe global maximum cell size in the domain of the geometry. It isalso the default cell size.The above two options are the mandatory options for using cfMesh.
boundaryCellSizeThe global maximum cell size of the boundary faces. Also the defaultboundary cell size.
boundaryCellSizeRefinementThicknessThe distance from the boundary at which the boundary cell size isapplied. This is a global setting.
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Section
Subsection
Continued
minCellSize.This performs automatic refinement in regions where the cell size islarger than the feature size. This is a global setting.
localRefinementThis is used to specify a local refinement in the domain at theboundaries. It is done by specifying the patch name, its cell size andoptionally the distance from the patch for which the specified sizeshould be used.
objectRefinementsIt is used to specify refinement zones in the domain. Different typesare available namely box, cone, hollow cone, sphere and lines.
surfaceMeshRefinementUses a surface file to define a refinement zone in the domain. The cellsize and refinement zone thickness is used to specify the requiredsizes.
Jethro Raymond Nagawkar Openfoam presentation 2015-12-08 5 / 23
Section
Subsection
Installing cfMesh
cfMesh is installed along with Foamextend-3.2. However is can beinstalled separately with other versions as well.Go to http://sourceforge.net/projects/cfmesh/ and download thecfMesh-v1.1.1.tgz file. Save it anywhere you like.
tar -xvzf cfMesh-v1.1.1.taz
cd cfMesh-v1.1.1/
OF24x
source $WM_PROJECT_DIR/etc/bashrc .
./Allwmake
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