geoOverlap

1D/2D Overset with OpenFOAM(Conservative) - tested with OpenFOAM-v1812

External Dependencies(included)

Octree search: https://github.com/jbehley/octree (No compilation required)

sparseMatrix: https://github.com/uestla/Sparse-Matrix (OpenFOAM based compilation required inside folder sparseMatrix)

itsol:https://github.com/huiscliu/itsol (standard compilation required inside folder itsol-master)

Case Directory

Overlapping 1D/2D regions case can be found in run/

Meshing

For 1D, meshes are with empty patches on the y and the z directions. Navigate to run/meshes/ and there are two regions region1 and region2. Execute blockMesh inside each of these regions. Once done with meshing, run the script ./createLinks.sh(Just once!). This establishes a link between the meshes inside meshes/ and the root folder inside constant/

For 2D, several mesh refinements can be generated by issuing the command ./switchMesh.sh refinementLevel

where refinementLevel is either tiny, coarse, medium or fine.

Running Poisson Cases

1D Poisson: onedOverset (basic run)

onedOverset -cons (with a correction)

2D Poisson: twoDOverset options

Various options are as follows:

-neumannrhs: Solve using Neumann BCs on left and top boundaries (You also need to change the 0/T files appropriately). The default option in 0/ folder is the Neumann BCs.

-inv : Use inverse distance interpolation instead of polynomial interpolation.

-rbf : Use RBF 2nd order interpolation

-cons : Activate conservative correction

Since the default BCs are already Partly Neumann, to execute the code (using RBF):

twoDOverset -neumannrhs -rbf

Outputs for Poisson runs

1. For 1D: Solution on both meshes written in solution.0 and solution.1
2. For 1D: The matrix and the RHS also written in matrix.txt
3. L2 norm of the error and conservation error also reported for each run

Compiling and Running NS Cases

As of Nov 2021, the Poisson flux correction has been extended to the incompressible Navier-Stokes equations. The sources for these are in src.NS and a wmake has to be issued inside that folder.

The full pressure equation can take advantage of the conservative fix by running:

simpleFoamCons -cons

The cell adjacent to the first overset interface on mesh 0 will be used as the flux correction/balance cell. One can change this behaviour by specifying either the flux balance cell or the interface by

simpleFoamCons -cons -ointerface

or

simpleFoamCons -cons -ocell