Turbulence - Theory and Modeling MVK140/MMV010F

Introduction to OpenFOAM

Piero Iudiciani, Holger GrosshansDivision of Fluid Mechanics, 15.11.11

Lund University / Division of Fluid Mechanics / 25.3.2011

Computer Exercises

• Introduction to OpenFOAM

• Computer Exercise 1 * 17.11.11 15:15 – 17:00

• Computer Exercise 2 * 24.11.11 13:15 – 15:00

* if you cannot join the exercises, write a short report an send it to :

piero.iudiciani@energy.lth.se and

holger.grosshans@energy.lth.se

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

How to get OpenFOAM

Unix/Linux version 1.7 :www.opencfd.co.uk

MS Windows version 1.5 (used in this lab) :http://sourceforge.net/projects/openfoam-mswin/

DOCUMENTATION version 1.7 :http://foam.sourceforge.net/doc/Guides-a4/UserGuide.pdf

DOCUMENTATION version 1.5 :C:\win32app\cfd\OpenFOAM-1.5\doc\Guides-a4\UserGuide.pdf

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Tree structure

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Tree structure

• OpenFOAM is a C++ library of applications

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Tree structure

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

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

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

The pitzDaily case

• Create a folder turb_labOF in your local directory

• Copy the pitzDaily case

C:\win32app\cfd\OpenFOAM-1.5\tutorials\simpleFoam\pitzDaily

in this folder.

• Open OpenFOAM Designer and do File -> OpenCase to open your pitzDaily case

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

OpenFOAM Designer

Input files for the case Editor for the input

files

OpenFOAM applications

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Create the Mesh

• Look into the constant/polyMesh folder

• Do MeshUtilities -> Generation -> blockMesh -> right click, start

• View → refresh

• Look into the constant/polyMesh folder to see that the mesh was created

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Look at the mesh in Paraview

• Create an empty file pitzDaily/pitzDaily.OpenFOAM in OpenFOAM Designer (File-> New)

• Open paraview

• Add the pluggins as instructed

• Don't close paraView anymore !

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Look at the mesh in ParaviewFile → open → ….pitzDaily.OpenFOAM

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

check controlDict

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

check boundary conditions

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

check turbulence model

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Run Case pitzDaily

• run solver → incompressible → 'simpleFoam'

• Check the results in paraView : load the new time steps by clicking the box ’update GUI’ and ’Apply’.

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

Check the results in paraview

• contourplot

• streamlines

• vectorplot

• plot over line

Lund University / Division of Fluid Mechanics / Piero Iudiciani, Holger Grosshans / 15.11.1011

inlet conditions

• copy the pitzDaily case to a new case

• change in '0/U' the inlet velocity from 10 m/s to 40 m/s

• run blockMesh and simpleFoam

• look at the results in paraView