OpenFOAM tutorial

OpenFOAM tutorial

OpenFOAM tutorial Discover it, tame it, use it

by Victor Pozzobon ([email protected]) 26th December 2016

Version 1.03

Disclaimer “This offering is not approved or endorsed by OpenCFD Limited, the producer of the OpenFOAM software and owner of the OPENFOAM® and OpenCFD® trade marks.”

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Introduction ●

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This tutorial is a brief introduction to OpenFOAM This document is a step by step guide It was done to be used on its own, there should be no need for a presenter (myself) It was designed for OpenFOAM 3.0.1 and validated with 16.06+ version (changes may appear in superior versions)

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OpenFOAM ●

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OpenFOAM (Open Field Operation And Manipulation) is a versatile equations solver Why do I use OpenFOAM ? - free - powerful - opensource - allows a lot of freedom - no GUI (helps to focus on the equations)

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How to use this tutorial ●

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Almost every command will passed through the terminal. For example, when you see: gedit system/controlDict you type it in the terminal As OpenFOAM has no GUI, we will modify files. For example, when you see this kind of picture: modify the file so that its content is the same before you save it

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Battle plan ●

Ex. 1: Cavity

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- getting started ●

- solver modifying (1/2)

Ex. 2: Square tube - mesh manipulation - steady state

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- solver modifying (2/2) ●

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Ex. 4: 2D flat plate

Ex. 8: Heating pipe Ex. 9: Cake backing - field affectation

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Ex. 5: 2D pipe - axisymmetric problem

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Ex. 7: Tubular reactor - custom boundary condition

- 2D problem ●

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Ex. 3: 1D beam - 1D problem - transient

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Ex. 6: Tubular reactor

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Ex. 10: Tank filling - importing a mesh - run in parallel 6

Ex. 1: Cavity - Objectives ●

Accessing your work directory

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Accessing OpenFOAM tutorials

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Understanding case architecture

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Running your first OpenFOAM case

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Postprocessing with ParaFoam (Paraview with OpenFOAM reader module): data modifying, line date / point data extraction

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Ex. 1: Cavity - Run ●

To access your directory type in a terminal: run

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To get the full path type: pwd You will see: /home/YourName/OpenFOAM/YourName-OpenFOAMVersion/run

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Ex. 1: Cavity - Tutorials ●

To copy official tutorials to your run: cp -r $FOAM_TUTORIALS Tutorials

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Go to the case directory: cd Tutorials/incompressible/icoFoam/cavity/cavity

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Ex. 1: Cavity - Architecture Case directory Initial conditions directory Pressure / Velocity initial conditions Mesh directory

Physical properties values Solving parameters directory Mesh instructions Parameters file 26th December 2016

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Ex. 1: Cavity – Run the case ●

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Once in 'cavity' directory, create the mesh: blockMesh Call the solver: icoFoam (you can note that the solver created several directories e.g. '0.1'. These directories contain data for a given time) Watch the results: paraFoam

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Ex. 1: Cavity – Postprocessing Data analysis pipeline

Load the case

Load geometric fields Load the fields 26th December 2016

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Ex. 1: Cavity – Postprocessing Current time step Plotted data Plot Rescale legend legend

Observation tools Time step tool Legend

Scene

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Ex. 1: Cavity – Postprocessing ●

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Make it look shinier: Filters / Alphabetical / Cell data to point data Calculate something: Filters / Common / Calculator OR Extract profiles: Filters / Data Analysis / Plot Over Line Extract histories: Filters / Data Analysis / Plot Selection Over Time

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Battle plan ●

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From Ex. 2 to Ex. 5, we are going to learn how to use existing solvers in different configurations. We are going to set 3D, 2D planar, 2D axisymmetrical and 1D cases We are going to explore postprocessor basic functions

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Ex. 2: Square tube - Objectives ●

Creating your own case

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Creating a mesh

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Specifying initial / boundary conditions

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Specifying physical properties values

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Solving a steady state problem

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Postprocessing with ParaFoam: integrating variable / checking mass conservation

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Ex. 2: Square tube – Case setup ●

Solving steady state incompressible Navier-Stokes equation, in a fourth of a square pipe ⃗ dU p 2 ⃗ ⃗ ⃗ + U ∇ . U =−∇ ρ +η ∇ U dt

2 cm

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Ex. 2: Square tube – A new case ●

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Go to your 'run' directory: run Copy an existing case: cp -r $FOAM_TUTORIALS/incompressible/simpleFoam/pitzDaily/ Ex2 Move to the case directory: cd Ex2 Open the mesh file: gedit system/blockMeshDict

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Ex. 2: Square tube – A new mesh ● ●

A fourth of a square tube with symmetry plane Points have to be prescribed in order to bluid a 5 6 mesh (consider doing a sketch)

x

z 2

Wall 4

7

1

Inlet

Outlet y

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Ex. 2: Square tube – A new mesh ●

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Beware, the points are to be prescribed in order not to back cross a line Do (0 4 7 3) 4

7

0

3

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Scaling factor Block division along axis Points locations Division grading

Points needed to Pozzobon Victor build a block

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Ex. 2: Square tube – A new mesh ●

Face name

Avoid (0 3 4 7) 4

7 Face type

0

3

Point sequence delimiting the face Wall

Inlet

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Outlet

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Ex. 2: Square tube – A new mesh ●

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Compile your mesh: blockMesh Check its quality: checkMesh

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Ex. 2: Square tube – Turbulence model and parameters ●

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Choose the turbulence model. In this case, there is no turbulence: gedit constant/turbulenceProperties Because we disabled the turbulence, there will be no need to specify: epsilon, k, nut and nuTilda fields: rm 0/epsilon 0/k 0/nut 0/nuTilda 0/f 0/omega 0/v2

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Ex. 2: Square tube – IC / BC ●

Open initial / boundary conditions files in the '0' directory: gedit 0/p gedit 0/U Physical field

Physical field unit [ kg m s K mol A Cd] Initial condition Boundary condition on 'inlet' patch 26th December 2016

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Ex. 2: Square tube – IC / BC, p ●

Open initial / boundary conditions for the pressure field

Field type, here scalar

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Ex. 2: Square tube – IC / BC, U ●

Open initial / boundary conditions for the velocity field

Field type, here vector

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Ex. 2: Square tube – Setting values ●

Open transportProperties file, this is where physical properties value (e.g. viscosity) are specified: gedit constant/transportProperties

Property name Property dimension [ kg m s K mol A Cd] Property value Subdictionaries for some viscosity laws, can be removed in our case 26th December 2016

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Ex. 2: Square tube – Control values ●

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Open case control file: gedit system/controlDict Erase the “functions” and below End time = maximum number of iteration

Constant “time step” equals to 1 26th December 2016

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Ex. 2: Square tube – Control values ●

In steady state, the maximum number of iteration is prescribed using “endTime”. Yet, there is no variation in time. It is a “trick”, nothing more

Data are extracted every 5 iterations

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Ex. 2: Square tube – Run the case ●

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The mesh has already been built, so let's run the case: simpleFoam (it should converge in about 20 iterations) Have a look at the results: paraFoam

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Ex. 2: Square tube – Postprocessing ●

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Check mass conservation: Filters / Common / Slice Filters / Data Analysis / Integrate Variables Check velocity profile: Filters / Data Analysis / Plot Over Line

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Ex. 3: 1D beam - Objectives ●

Setting a 1D case

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Solving a transient problem

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Postprocessing with ParaFOAM: importing variables (other than p and U)

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Ex. 3: 1D beam – Case setup ●

Solving transient heat conduction in a 1D beam dT 2 =α ∇ T dt

Symmetry planes Cold side

Hot side

20 cm

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Ex. 3: 1D beam – Case creation ●

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Reach 'run' directory: run Copy an existing heat transfer case: cp -r $FOAM_TUTORIALS/basic/laplacianFoam/flange Ex3 cd Ex3 Clean the case directory: rm Allclean Allrun flange.ans Copy Ex2 mesh: cp ../Ex2/system/blockMeshDict system/.

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Ex. 3: 1D beam – Modifying mesh ●

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Modify file: gedit system/blockMeshDict Build mesh: blockMesh

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Ex. 3: 1D beam – IC / BC ●

Modify temperature file: gedit 0/T

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Ex. 3: 1D beam – Diffusivity ●

Modify transport property file: gedit constant/transportProperties

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Ex. 3: 1D beam – Control value ●

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Modify control dictionary: gedit system/controlDict Run the case: laplacianFoam Postprocess the case: paraFoam

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Ex. 3: 1D beam – Postprocessing ●

Check T, as a 'Volume field' when loading data

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Ex. 4: 2D flat plate - Objectives ●

Setting a 2D case

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Building a 2 block mesh

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Changing convergence criterion

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Postprocessing with ParaFoam: plotting streamlines

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Ex. 4: 2D flat plate – Case setup ●

Solving incompressible air flow above a flat plate, in steady state ⃗ dU p 2 ⃗ ⃗ ⃗ + U ∇ . U =−∇ ρ +η∇ U dt 30 cm

20 cm

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Ex. 4: 2D flat plate – Case creation ●

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Reach 'run' directory: run Copy an existing case: cp -r Ex2 Ex4 cd Ex4 Clean the case directory: foamListTimes -rm (this command removes time/iteration folders except the ‘0’ folder)

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Ex. 4: 2D flat plate – Mesh ●

We will create a mesh made of two blocks.

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Modify file: gedit system/blockMeshDict Top

Inlet

Block 1

Outlet

Symmetry wall Down

Plate Block 2

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Ex. 4: 2D flat plate – Creating mesh ●

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Create the two blocks blockMesh will merge them

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Ex. 4: 2D flat plate – Creating mesh ●

Set the faces

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Build mesh: blockMesh

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Ex. 4: 2D flat plate – IC / BC ●

Modify velocity file: gedit 0/U

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Ex. 4: 2D flat plate – IC / BC ●

Modify pressure file: gedit 0/p

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Ex. 4: 2D flat plate – Viscosity ●

Modify the kinematic viscosity: gedit constant/transportProperties

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Ex. 4: 2D flat plate – Convergence ●

Modify pressure / velocity convergence criteria: gedit system/fvSolution

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In this case, there are a lot of options. Some solvers are much simpler

Solver Solved type and options field 26th December 2016

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Ex. 4: 2D flat plate – Convergence ●

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Simulations can be stopped automatically once residues values have been reached For 2D cases, the unsolved component of the velocity vector prevents the solver from reaching the tolerance most of time. Therefore, a number of iterations has to be prescribed Residues values set for convergence

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Ex. 4: 2D flat plate – Run the case ●

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The mesh has already been built The controlDict has not changed from Ex2. The solver will run for 100 iterations. It is enough to get the residues below 10-6 gedit system/controlDict Run the case: simpleFoam Have a look at the results: paraFoam

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Ex. 4: 2D flat plate – Postprocessing ●

Lower the first scene opacity: 'Click on the filter' / Display / Styling / Opacity

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Plot the streamline from the inlet: Filters / Common / Stream Tracer Set streamlines' sources as a line, not a point: 'Click on stream tracer' / Properties / Seeds / Seed type => High resolution line source Set the line you want using the coordinates

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Ex. 4: 2D flat plate – Postprocessing

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Ex. 5: 2D pipe - Objectives ●

Creating a 2D axisymmetrical mesh

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Nothing fancy ...

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Ex. 5: 2D pipe – Case setup ●

Solving incompressible flow in a 2D axisymmetrical pipe, in steady state ⃗ dU p 2 ⃗ ⃗ ⃗ + U ∇ . U =−∇ ρ +η∇ U dt 10 cm

1 cm

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Ex. 5: 2D pipe – Case creation ●

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Reach 'run' directory: run Copy an existing case: cp -r Ex2 Ex5 Go to the new case directory: cd Ex5 Clean the case directory: foamListTimes -rm

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Ex. 5: 2D pipe – Mesh ●

Modify file: gedit system/blockMeshDict Axis

5°

Outlet

Inlet Front and Back

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Wall Pozzobon Victor

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Ex. 5: 2D pipe – Block creation ●

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Draw a wegde, with a 5° angle (twice 2.5°) Points 1, 2 and 3 are not used to build the geometry. OpenFOAM uses them to define x, y and z directions : - point 0 to point 1 = x - point 1 to point 2 = y - point 0 to point 4 = z

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cos(2.5°) sin(2.5°)

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Ex. 5: 2D pipe – Patches creation ●

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In order to do things by the book, create two 'wedge' patches (here, 'front' and 'back') It would have worked with only one, but checkMesh would have returned an error

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Ex. 5: 2D pipe – IC / BC p ●

Set pressure boundary / initial conditions: gedit 0/p

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Ex. 5: 2D pipe – IC / BC U ●

Set veolicty boundary / initial conditions: gedit 0/U

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Ex. 5: 2D pipe – Run the case ●

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(As usual now) The mesh has already been built, the controlDict has not changed from Ex2. As for Ex4, we have to set the desired number of iterations: gedit system/controlDict So let's run the case: simpleFoam Have a look at the results: paraFoam

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Ex. 5: 2D pipe – Postprocessing ●

E.g. check velocity profile

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Battle plan ●

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We have used two different builtin solvers (icoFoam, simpleFoam and laplacianFoam) We have set cases in 3D, 2D planar, 2D axisymmetrical and 1D configurations We have learnt how to process data with Paraview (paraFoam) We are going to learn how to solve our own equations and set fancy cases

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Ex. 6: Tubular reactor – Objectives ●

Create our own solver

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Use basic operators

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Create the associated case

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Ex. 6: Tubular reactor – Case setup ●

1D tubular reactor with heterogeneous catalysis on porous media without chemical reaction in steady state / hydrodynamics only ⃗ =0 ∇ .U

⃗ = −κ U μ ∇p

∇ 2 p=0 Symmetry planes

Inlet

Outlet

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Ex. 6: Tubular reactor – Solver directory creation ●

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Reach 'run' directory: run Create a solver directory: mkdir solvers Copy an existing solver: cp -r $FOAM_APP/solvers/basic/laplacianFoam solvers/. Rename the solver directory: mv solvers/laplacianFoam solvers/tubeFoam

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Ex. 6: Tubular reactor – Solver cleaning up ●

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Move to solver directory: cd solvers/tubeFoam Clean the directory: wclean rm write.H

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Rename the file: mv laplacianFoam.C tubeFoam.C

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Ex. 6: Tubular reactor – Solver modification ●

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Modify compilation file: gedit Make/files You can specify compilation options: gedit Make/options (None need to be applied here)

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Ex. 6: Tubular reactor – Solver modification / createFields.H ●

Modify createFields.H to create the new fields: gedit createFields.H Pressure field (scalar field)

Velocity field (vector field) 26th December 2016

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Ex. 6: Tubular reactor – Solver modification / createFields.H ●

Modify createFields.H to read the physical properties: gedit createFields.H

Physical property called 'Mu' 26th December 2016

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Ex. 6: Tubular reactor – Solver modification / tubeFoam.C ●

Modify tubeFoam.C to specify the equations that will be solved: gedit tubeFoam.C Time loop Correction loop (not mandatory) Solved equations (implicit '=0')

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Ex. 6: Tubular reactor – Solver compilation ●

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Clean the directory and compile: wclean; wmake If you get an error, here is what to do: 1. Read the expection message 2. Get error file and line number

Error file and line number

3. Take care of it

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Ex. 6: Tubular reactor – Case creation ●

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Now that the solver has been compiled, let's create the case we are going to solve. Since it is a 1D case, copy Ex3 (1D thermal beam) case directory: run cp -r Ex3 Ex6 Go to the case directory, clean it: cd Ex6 foamListTimes -rm

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Ex. 6: Tubular reactor – Mesh creation ●

Create the mesh: gedit system /blockMeshDict

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Ex. 6: Tubular reactor – IC / BC ●

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Build the mesh: blockMesh Create IC / BC files: mv 0/T 0/p cp 0/p 0/U gedit 0/p 0/U

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Ex. 6: Tubular reactor – IC / BC Pressure field (scalar field)

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Velocity field (vector field)

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Ex. 6: Tubular reactor – Physical properties ●

Modify physical properties file: gedit constant/transportProperties

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Ex. 6: Tubular reactor – Numerical schemes ●

Modify numerical schemes in order to specify a steady state resolution: gedit system/fvSchemes

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Ex. 6: Tubular reactor – Solver parameters ●

Modify solver parameters: gedit system/fvSolution

Specify tolerance on pressure equation as single iteration stopping criterion Number of correction iteration (used for non orthogonal meshes) Specify tolerance on pressure equation as simulation stopping criterion

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Ex. 6: Tubular reactor – Control parameters ●

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Modify solver parameters: gedit system/controlDict In this case, the solver is only calculating a Laplacian operator, Thus, a 10-6 residue is reached quite fast (2 iterations) Changing it is not mandatory

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Ex. 6: Tubular reactor – Run it ●

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Let's run the case: tubeFoam Process it: paraFoam

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Ex. 7: Tubular reactor – Objectives ●

Create our own solver with more complex equations

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Use common operators

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Evolving a case

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Ex. 7: Tubular reactor – Case setup ●

1D tubular reactor with chemical reaction, in transient state A +B=C

dA 2 ⃗ ω=v AB + ∇ .( U A)= D ∇ A−ω dt dB 2 ⃗ ⃗ =0 +∇ .( U B)=D ∇ B−ω ∇ .U dt dC 2 ⃗ + ∇ .( U C)=D ∇ C +ω Symmetry dt planes Inlet

2

∇ p=0 ⃗ = −κ U μ ∇p Outlet

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Ex. 7: Tubular reactor – Solver directory creation ●

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Reach 'run' directory: run Move to solver directory: cd solvers Copy the existing solver: cp -r tubeFoam tubeChemFoam Move to and clean the directory: cd tubeChemFoam wclean

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Ex. 7: Tubular reactor – Solver modification ●

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Rename the file: mv tubeFoam.C tubeChemFoam.C Modify compilation file: gedit Make/files

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Ex. 7: Tubular reactor – Solver modification / createFields.H ●

Modify createFields.H to create the species fields: gedit createFields.H

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Defined in the source code

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Ex. 7: Tubular reactor – Solver modification / createFields.H ●

Modify createFields.H to read the physical properties: gedit createFields.H

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Ex. 7: Tubular reactor – Solver modification / tubeChemFoam.C ●

Modify tubeChemFoam.C to add species fields: gedit tubeChemFoam.C

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Ex. 7: Tubular reactor – Solver compilation / Case creation ●

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Clean the directory and compile: wclean; wmake Move to cases directory: run Copy Ex6 directory: cp -r Ex6 Ex7

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Move to the case directory: cd Ex7

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Ex. 7: Tubular reactor – Case creation ●

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Clean the directory: foamListTimes -rm Build the mesh: blockMesh Modify physical properties: gedit constant/transportPropeties

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Ex. 7: Tubular reactor – IC / BC ●

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Create file for the species fields: cp 0/p 0/A cp 0/p 0/B cp 0/p 0/C

A field

Keep the existing files for pressure and velocity Modify species files: gedit 0/A gedit 0/B gedit 0/C

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Ex. 7: Tubular reactor – IC / BC B field

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C field

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Ex. 7: Tubular reactor – Numerical schemes ●

Set numerical schemes: gedit system/fvSchemes

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Ex. 7: Tubular reactor – Solver parameters ●

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Add solvers: gedit system/fvSolution Due to the use of the divergence, we need to use asymmetric solvers for the species fields

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Ex. 7: Tubular reactor – Control parameters ●

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Add solvers: gedit system/controlDict Run the case: tubeChemFoam Process it: paraFoam

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Ex. 7: Tubular reactor – Nice pics

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Ex. 8: Heating pipe – Objectives ●

Modify an existing solver

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Create a variating boundary condition

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Evolve a case

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Ex. 8: Heating pipe – Case setup ●

Solving incompressible flow in a 2D axisymmetrical pipe with heat transfer , in steady state 10 cm

1 cm

⃗ dU p 2 ⃗ ⃗ ⃗ + U ∇ . U =−∇ ρ +η∇ U dt 26th December 2016

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Ex. 8: Heating pipe – Case setup ●

Solving incompressible flow in a 2D axisymmetrical pipe with heat transfer, in steady state dT ⃗ T =−∇ .(−k ∇ T ) ρ Cp +ρ Cp ∇ . U dt T inlet = 20 °C

T surrounding = 80 °C

−k ∇ T . ⃗n =−h(T −T sur ) 26th December 2016

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Ex. 8: Heating pipe – Solver creation ●

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Reach 'run' directory: run Move to solver directory: cd solvers Copy simpleFoam: cp -r $FOAM_APP/solvers/incompressible/simpleFoam . mv simpleFoam simpleThermFoam Move to the new solver directory: cd simpleThermFoam

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Ex. 8: Heating pipe – Solver creation / modification ●

Clean the directory: rm -r porousSimpleFoam/ SRFSimpleFoam/ simpleFoam.dep

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Clean the directory: wclean Rename simpleFoam: mv simpleFoam.C simpleThermFoam.C Change compilation file: gedit Make/files

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Ex. 8: Heating pipe – Solver modification / createFields.H ●

Add temperature field and related physical properties to createFields.H: gedit createFields.H

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Ex. 8: Heating pipe – Solver modification / createFields.H ●

Carry on ...

Loading turbulence model (we do not use it in this case)

Add temperature field 26th December 2016

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Ex. 8: Heating pipe – Solver modification / createFields.H ●

Carry on ... Loading transportProperties dictionary

Loading physical values

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Ex. 8: Heating pipe – Solver modification / simpleThermFoam.C ●

Modify solver to add temperature equation: gedit simpleThermFoam.C

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Ex. 8: Heating pipe – Solver compilation / boundary condition ●

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Clean the directory and compile: wclean; wmake Move to cases directory: run Create a directory to store boundary condition: mkdir boundaryConditions

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Move to this directory: cd boundaryConditions

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Ex. 8: Heating pipe – Create boundary condition ●

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Copy an existing boundary condition: cp -r $FOAM_SRC/finiteVolume/fields/fvPatchFields/derived/tot alTemperature convectiveHeatFlux Move to the convectiveHeatFlux directory and clean it (if need be): cd convectiveHeatFlux rm totalTemperatureFvPatchScalarField.dep

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Ex. 8: Heating pipe – Modify boundary condition ●

Renane the boundary condition files: mv totalTemperatureFvPatchScalarField.C convectiveHeatFluxFvPatchScalarField.C mv totalTemperatureFvPatchScalarField.H convectiveHeatFluxFvPatchScalarField.H

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Ex. 8: Heating pipe – Compilation rules ●

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Create Make folder: mkdir Make Create rule files: gedit Make/files Make/options files

options

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Ex. 8: Heating pipe – Modify boundary condition .H file ●

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Modify convectiveHeatFluxFvPatchScalarField.H: gedit convectiveHeatFluxFvPatchScalarField.H Replace all “totalTemperature” occurences by “convectiveHeatFlux” (consider using ctrl + H)

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Ex. 8: Heating pipe – Modify boundary condition .H file

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Ex. 8: Heating pipe – Modify boundary condition .H file

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Ex. 8: Heating pipe – Modify boundary condition .C file ●

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Modify convectiveHeatFluxFvPatchScalarField.C: gedit convectiveHeatFluxFvPatchScalarField.C Replace all “totalTemperature” occurences by “convectiveHeatFlux” (consider using ctrl + H) Change scalar affection to a gradient affectation Set thermal gradient equation

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Ex. 8: Heating pipe – Modify boundary condition .C file

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Ex. 8: Heating pipe – Modify boundary condition .C file

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Ex. 8: Heating pipe – Modify boundary condition .C file

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Ex. 8: Heating pipe – Modify boundary condition .C file

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Compile the boundary condition: wclean; wmake OR wclean; wmake libso

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Ex. 8: Heating pipe – Create case directory ●

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Move to cases directory: run Copy Ex5 directory: cp -r Ex5 Ex8

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Move to the case directory: cd Ex8

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Ex. 8: Heating pipe – Create case directory ●

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Clean the case directory: foamListTimes -rm Modify physical properties: gedit constant/transportPropeties

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Ex. 8: Heating pipe – IC / BC ●

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Create temperature field: cp 0/p 0/T Edit the field: gedit 0/T

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Ex. 8: Heating pipe – Solver ●

Pick a solver for the temperature field: gedit system/fvSolution Deliberately high to prevent the problem with the unsolved component of the velocity field (cf. Ex 4)

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Ex. 8: Heating pipe – Schemes ●

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Choose numerical scheme for temperature divergence: gedit system/fvSchemes Keep the default Laplacian scheme

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Ex. 8: Heating pipe – Specify library use ●

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Modify controlDict to specify the use of convectiveHeatFlux boundary condition: gedit system/controlDict 1000 iterations maximum should be enough (mine converged after 402 iterations)

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Ex. 8: Heating pipe – Run the case ●

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Create the mesh: blockMesh Run the case: simpleThermFoam Open paraFoam: paraFoam

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Ex. 8: Heating pipe – Process the case ●

Have a look at the temperature field:

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Ex. 9: Cake baking – Objectives ●

Modify an existing solver

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Set a field that depend on another field

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Set custom field

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Use an existing case as initial condition

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We are going to simulate the backing of a cake: - heating up with chocolate melting (20 min, 180°C) - cooling down with chocolate solidification (1 hour)

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Ex. 9: Cake baking – Case setup ●

2D cake backing, with chocolate phase change dT ρ Cp =−∇ .(−k ∇ T )+Q dt −Ea dC −Ea T RT =− A 1 e C + A2 e LC dt −Ea d LC −Ea T =−A 2 e LC + A 1 e RT C dt 1

2

1

1 dC dLC Q= ( − )Δ H 2 dt dt T surrounding = 180 °C

−k ∇ T . ⃗n =−h(T −T sur )

2

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Ex. 9: Cake baking – Solver directory creation ●

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Reach 'run' directory: run Move to solver directory: cd solvers Copy the existing solver: cp -r tubeFoam cakeFoam Move to and clean the directory: cd cakeFoam wclean

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Ex. 9: Cake baking – Set compilation rules ●

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Rename tubeFoam: mv tubeFoam.C cakeFoam.C Change compilation file: gedit Make/files

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Ex. 9: Cake baking – Modiy createFields.H ●

Modify fields and physical properties: gedit createFields.H

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Ex. 9: Cake baking – Modiy createFields.H

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Ex. 9: Cake baking – Modify the solver ●

Rename tubeFoam: gedit cakeFoam.C

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Ex. 9: Cake baking – Compile the solver / create case ●

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Compile the solver: wclean; wmake Move to 'run': run Create the case directory: cp -r Ex4 Ex9 Move to the case directory: cd Ex9

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Ex. 9: Cake baking – Prepare case ●

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Clean the case: foamListTimes -rm rm 0/U Create fields files: cp 0/p 0/C cp 0/p 0/LC mv 0/p 0/T

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Ex. 9: Cake baking – Create mesh ●

Boundary name and location: Top

Left Down

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Ex. 9: Cake baking – Create mesh ●

Modify the mesh: gedit system/blochMeshDict

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Ex. 9: Cake baking – IC / BC ●

Modify the mesh: gedit 0/T

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Ex. 9: Cake baking – IC / BC ●

Modify the mesh: gedit 0/C

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Ex. 9: Cake baking – IC / BC ●

Modify the mesh: gedit 0/LC

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Ex. 9: Cake baking – Chocolate ●

We have to specify the position of every chocolate chip. In this case, only three pieces will be set. First, copy an existing dictionary: cp $FOAM_TUTORIALS/multiphase/interFoam/ras/damBrea k/system/setFieldsDict system/.

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Ex. 9: Cake baking – Chocolate ●

Set the chips location and shape: gedit system/setFieldsDict

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Ex. 9: Cake baking – Set properties for the heating phase ●

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Set the physical properties for the heating phase Chocolate solidification parameter are set to 0: gedit constant/transportProperties

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Ex. 9: Cake baking – Set properties for the heating phase ●

Set the case to transient and specify solver features: gedit system/fvSchemes gedit system/fvSolution

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Ex. 9: Cake baking – Set control parameters ●

The heating phase lasts 20 min (1800 s): gedit system/controlDict

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Ex. 9: Cake baking – Run the case ●

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Create the mesh: blockMesh Set chocolate field: setFields Solve the case: cakeFoam

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Ex. 9: Cake baking – Modify the case ●

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Now that the heating phase has been run, modify physical properties value: gedit constant/transportProperties This time, chocolate melting is disabled and chocolate solidification is enabled

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Ex. 9: Cake baking – Reset control parameters ●

The cooling phase lasts 60 min (3600 s): gedit system/controlDict The last iteration will be used as initialization

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Ex. 9: Cake baking – Rerun the case ●

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Solve the last part of the case: cakeFoam Process the case: paraFoam

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Ex. 9: Cake baking – Process the case Temperature during the cooldown

Chocolate chips location

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Ex. 10: Tank filling - Objectives ●

This case is really basic. Its purpose is only to discuss topics that were left uncovered

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Import a mesh created with an external tool

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Run a case in parallel

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Exporting an animation

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Ex. 10: Tank filling – Case setup ●

Transient filling of a tank. Initially, it is full of air, then, we are going to fill it using the two phases flow solver interFoam Air outlet

Water inlet

Tank walls

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Ex. 10: Tank filling – A new case ●

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Go to your 'run' directory: run Copy 'damBreak': cp -r $FOAM_TUTORIALS/multiphase/interFoam/laminar/dam Break/damBreak/ Ex10 Move to the case directory: cd Ex10

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Ex. 10: Tank filling – Importing the mesh ●

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The mesh is called 'Tank.unv'. It was drawn using salome. It should have already been provided to you, if this is not the case, you can find it here: http://perso.mines-albi.fr/~vpozzobo/dl/Tank.unv Move the mesh file to the case directory: mv 'somewhere'/Tank.unv Ex10/. Import the mesh: ideasUnvToFoam Tank.unv

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Ex. 10: Tank filling – Importing the mesh ●

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There is no need to build the mesh using blockMesh, is has already been done when importing it. Yet, it has to be resized: atmosphere transformPoints -scale '(0.001 0.001 0.001)' You can check the mesh using paraFoam: paraFoam

inlet fixedWalls

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Ex. 10: Tank filling – IC / BC ●

Modify velocity boundary conditions according to the case setup: gedit 0/U

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Ex. 10: Tank filling – IC / BC ●

Modify the pressure boundary conditions: gedit 0/p_rgh

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Ex. 10: Tank filling – IC / BC ●

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Copy the water phase file: cp 0/alpha.water.org 0/alpha.water Keep the '.org' file. It is used as a backup in case you would have modified the initial condition using setFields To prevent any problem, move the '.org' file to the case root mv 0/alpha.water.org .

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Ex. 10: Tank filling – IC / BC ●

Modify the water boundary conditions: gedit 0/alpha.water

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Ex. 10: Tank filling – Setting gravity ●

Modify gravity orientation, so that the tank will be vertical: gedit constant/g

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Ex. 10: Tank filling – Running parallel ●

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OpenFOAM runs in parallel using a decomposition of mesh and fields. You can specify the cut yourself or ask scotch to do it for you (our call here). As a good rule of thumb, each processor should at least have 30000 cells to compute, if you want to see an increase in computational speed. Copy the decomposition dictionary from an existing case: cp $FOAM_TUTORIALS/multiphase/interDyMFoam/ras/damBreakWithO bstacle/system/decomposeParDict system/.

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Ex. 10: Tank filling – Running parallel ●

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Modify the decomposition dictionary: gedit system/decomposeParDict Once it is done, decompose the case: decomposePar

Number of processors that are going to be used

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Ex. 10: Tank filling – Control values ●

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Open case control file: gedit system/controlDict The tank takes about 40s to fill up, which represented a cpu time of 2 days for me. So set endTime according to your liking. I would advice 0.30s. It still requires 30 minutes to run

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Ex. 10: Tank filling – Control values ●

Note that interFoam uses an adaptive time step

Maximum Courant number Maximum time step (in second)

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Ex. 10: Tank filling – Run the case ●

The mesh has already been built. The case has been split between processors, so let's run the case: mpirun -np 2 interFoam

Number of processors you want to use (has to be in agreement with decomposeParDict)

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Ex. 10: Tank filling – Post processing the case ●

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The case can then be processed. First, create a new directory to store the pictures that we will use to build the animation: mkdir Extraction Then launch the post processor: paraFoam

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Ex. 10: Tank filling – Postprocessing ●

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Load all the fields, then set opacity of the base filter to 0.1: Ex10.OpenFOAM / Style / Opacity Add a contour filter, on alpha.water field, with a threshold of 0.1: Filters / Common / Contour Change the background color to white: Edit / View Settings ... / Choose color

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Ex. 10: Tank filling – Postprocessing ●

Set the camera angle to your liking by using the mouse or the 'Adjust Camera' tool:

Adjust Camera button

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Ex. 10: Tank filling – Postprocessing ●

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Save the individual picture: File / Save Animation ... Click 'Save Animation' on the prompted form (the settings do not matter here) Pick 'Extraction' folder and choose a name for the pictures (I chose 'Water') Now paraFoam is filling 'Extraction' directory with frames of the animation

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Ex. 10: Tank filling – Postprocessing ●

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Close paraFoam and go 'Extraction' folder: cd Extraction Create your .gif file: convert -delay 10 -loop 0 Water.*.png Your.gif Time between two frames in milliseconds

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It's over ●

This tutorial is over, thank you for your attention

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I hope you enjoyed it

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It was just a brief and partial overview of OpenFOAM possibilities Please feel free to contact me: [email protected]

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The extra mile ●

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The open source software, I use to draw and mesh complex geometries: SALOME: www.salome-platform.org Another open source software which can be used to process high volume results: VisIt: https://visit.llnl.gov Where I ask for help: CFD Online: www.cfd-online.com/Forums/openfoam

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It's over

Again, thank you for your attention.

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