[Tobi]

Dear community,

at the moment I am recording the latest community screencasts for OpenFOAM v8. During the YouTube videos we are going through a variety of different topics that should be known while using OpenFOAM. At the moment, the screencast series reached 12 videos and explains everything step-by-step starting at zero.
You will find the announced playlist here:

https://youtube.com/playlist?list=PL...eLWb6OZaMOHiST

Topic of the videos are summed up:

Part 1 - Introduction

• Introduction

Part 2 - Fluid Region Extraction

• Fluid region extraction
• Repairing the geometry
• Closing holes with different algorithms
• Merging/Sewing methods for closing gaps
• Tips & Tricks (maybe)
• Checking the created surface
• Intersections / Free boundaries

Part 3 - Surface Triangulation

• exporting STL files from the Geometry module (similar to a common CAD export)
• Extended surface triangulation
• Exporting the single named triangulated surfaces
• Giving information about the general file structure of an STL file (a reference to József Nagy's video is given)
• Combining the single STL files to a region STL file
• Analyzing the STL's in ParaView

Part 4 - Case Preperation for Meshing

• Background mesh generation using Salome®
• Mesh conversion using the »ideasUnvToFoam« application
• Creating missing files that are needed to run snappyHexMesh (including a general but brief description of what the files do) such as controlDict, fvSolutions, fvSchemes, snappyHexMeshDict, meshQualityDict
• And as always, Tobi live

Part 5 - SnappyHexMesh Castellated Meshing

• Analyzing the snappyHexMeshDict
• Explaining the control parameters of the castellatedMeshControls dictionary within the snappyHexMeshDict especially the keywords:
• maxLocalCells
• maxGlobalCells
• minRefinementCells
• maxLoadUnbalancing
• nCellsBetweenLevels
• features
• refinementSurface
• refinementRegions
• locationInMesh
• resolveFeatureAngle
• allowFreeStandingZoneFaces
• Set-up the control file of snappyHexMesh for the smoking pipe geometry
• Creating the first castellated meshes
• Resolving errors
• Analyzing partially the output of the application
• Showing the influence of the levels (x y) in combination with the feature angle approach

Part 5.1 - SnappyHexMesh castellatedMesh Complementary

• Refinement level
• nCellsBetweenLevels
• What is a castellatedMesh
• resolveFeatureAngle
• maxGlobalCells
• Use the regions of the STL file for individual refinement

Part 5.2 - SnappyHexMesh castellatedMesh Cell Types

• Cell type generation during the castellated process
• Explaining why we get polyhedron cells
• Hints for ParaView how to display the cell type
• Extract cells from the mesh in ParaView and display them correctly

Part 6 - SnappyHexMesh Snapping

• Explaining what snapping means
• Creation of the first snapped mesh and the influence of the parameter »tolerance«
• Resetting the »tolerance« parameter and recreating the mesh
• Explaining »feature Snapping«
• Influence of nFeatureSnapIter parameter
• Details about nSolveIter
• Details about nRelaxIter
• Details about nSmoothPatch and nonOrthogonality
• Further information regarding the control parameters (Engys PDF)
• Analysis of the mesh in general and optimization suggestions

Part 7 - SnappyHexMesh Layer Generation

• Activating the layer generation algorithm
• The »addLayersControls« dictionary
• The »relativeSize« description
• The »layers« sub-directory and the control settings
• Extended options for layer-set-up and definitions
• First layer generation and visualization (including explanation)
• How does snappyHexMesh add layers (algorithm idea)
• Other meshing examples with different layer-parameters

Part 8 - Boundary Condition for field U

• General information regarding the boundary condition files
• Why the application looks at the conditions in the file 0
• Copying existing boundary conditions
• Analyzing the complete text file U
• Deeper insight into the dictionary boundaryField {}
• Adapt the boundary conditions to our first set-up

Part - Boundary Condition for field p

• Starting analyzing the p file located in the 0 folder
• The units of the pressure [m²/s²] or [kg/m/s²]
• Advantage of dividing by the density for numerics
• The values of the pressure corresponding to the units
• The boundaryField
• Outlook to the next topics we are talking about

Part 10 - Solver Set-up & First Simulation

• Short introduction about what we are doing in the first simulation and explaining the simpleFoam solver
• Start the simpleFoam solver and analyzing the output (error) while giving general information about the fvSolution and fvSchemes files
• Explicit explanation of the fvSchemes file
• Explicit explanation of the fvSolution file
• Explicit explanation of the algorithm sub-dictionary we are using (brief)
• A few words regarding the field and matrix relaxation
• The transportProperties file that handles the fluid in use
• The momentumTransport file that handles the methodology we are using (laminar, RAS, LES)
• Generals hint regarding steady-state simulation and the controlDict settings - especially the time information
• Analyze the converged data using #ParaView​
• Glyph hack for #ParaView​
• Outlook to the next video

I hope these screencasts will support your work regarding OpenFOAM. Leave a comment here or give some feedback. You are warmly welcomed to share my work around your network.