CFD OpenFoam Sauna

Introduction

Use OpenFOAM to analyze the heating of water above sauna's oven. The problem is during the winter when the water freezes.

Other possibilities would be to create a simple Laplacian solver. $\rho c_{p}{\frac {\partial T}{\partial t}}=\nabla \cdot (k\nabla T)$ but I'd like to include Navier-Stokes equations and perhaps energy equation: ice melts into water, water freezes, latent heat is released and the interfaces move.

OpenFOAM

Workflow

1. Generate mesh
   • For example: blockMesh
2. Run solver
   • Example: laplacianFoam or: buoyantSimpleFoam
3. View results
   • paraFoam

Use foamSearch <keyword> or find $FOAM_TUTORIALS -type f | grep <keyword> . For example: find $FOAM_TUTORIALS -type f | grep laplacian will show every diffusion example. Start with laplacianFoam → buoyantSimpleFoam → conjugate heat transfer examples.

Tutorials

ls $FOAM_TUTORIALS

Installation and using

Installation is a long process, it takes many hours using yay.

ofoam

source /opt/OpenFOAM/OpenFOAM-13/etc/bashrc

Create an OpenFOAM case directory

mkdir -p ~/Documents/ofoam/constant/polyMesh
mkdir -p ~/Documents/ofoam/system
mkdir -p ~/Documents/ofoam/0

Put your Gmsh mesh there:

cp thermal_test.msh ~/Documents/ofoam/
cd ~/Documents/ofoam

Copy the tutorials to start easier

cp -r $FOAM_TUTORIALS/heatTransfer/chtMultiRegionFoam/* ~/Documents/ofoam/

Then convert:

gmshToFoam thermal_test.msh

This will populate:

constant/polyMesh/

Creating the mesh

Images

• 

  The mesh with three different parts.

gmsh

Gmsh to generate the triangles.

The command

gmsh model.geo -3
gmshToFoam model.msh

generates 3d triangulation and converts it.

yay -S gmsh-bin