Make/options: add

    -I$(LIB_SRC)/triSurface/lnInclude \
    -I$(LIB_SRC)/meshTools/lnInclude \
    -I../immersedBoundary/lnInclude


    -ltriSurface \
    -lmeshTools \
    -L$(FOAM_USER_LIBBIN) -limmersedBoundary \


createFields.H: add

#   include "createIbMasks.H"


solver:

1) add immersed boundary headers

#include "immersedBoundaryFvPatch.H"
#include "immersedBoundaryAdjustPhi.H"

2) on calculation of face fluxes (or their components), mask with faceIbMask

3) before to adjustPhi, add:

        // Adjust immersed boundary fluxes
        immersedBoundaryAdjustPhi(phi, U);

4) on explicit updates, add correctBoundaryConditions();

eg.

        U = fvc::reconstruct(phi);
        U.correctBoundaryConditions();

5) On reports of continuity error, add masking:

        Info<< "IB-masked continuity error = "
            << mag(cellIbMask*fvc::div(phi))().weightedAverage(mesh.V()).value()
            << endl;

  or use immersedBoundaryContinuityErrs.H

5) Chenge Courant number check to be IB-sensitive, using

  immersedBoundaryCourantNo.H