### Free Surface in 3 dimensions

Posted:

**27 Jun 2017, 22:37**Hi dudes!

I have a new query about the free surface solver.

I tried to extend the case "free surface sloshing 2d" to a 3d one. Instead of a square (2d), i defined a cube geometry (0.4m).

And unfortunately, it did not work so easily! i applied my free surface on my top surface of my cube and just wanted to observe the oscillation of the surface under the gravity effect!

The free surface solver requires "Free surface Orientation Vector" but i don't know how to define this "normal vector"... i'm not quite sure that the computation stops because of that... here it is the end of the message:

"...

FlowSolve: -------------------------------------

FlowSolve: NAVIER-STOKES ITERATION 6

FlowSolve: -------------------------------------

FlowSolve:

FlowSolve: Starting Assembly...

FlowSolve: Assembly:

: ..Assembly done

DefUtils::DefaultDirichletBCs: Setting Dirichlet boundary conditions

DefUtils::DefaultDirichletBCs: Dirichlet boundary conditions set

FlowSolve: Dirichlet conditions done

CRS_IncompleteLU: ILU(0) (Real), Starting Factorization:

CRS_IncompleteLU: ILU(0) (Real), NOF nonzeros: 2042830

CRS_IncompleteLU: ILU(0) (Real), filling (%) : 100

CRS_IncompleteLU: ILU(0) (Real), Factorization ready at (s): 0.06

1 0.4771E-10

ComputeChange: NS (ITER=6) (NRM,RELC): ( 0.31160846E-02 0.34240129E-08 ) :: n-s

FlowSolve: iter: 6 Assembly: (s) 2.13 12.59

FlowSolve: iter: 6 Solve: (s) 0.11 0.80

FlowSolve: Result Norm : 3.1160846049305630E-003

FlowSolve: Relative Change : 3.4240129054564090E-009

SingleSolver: Attempting to call solver

SingleSolver: Solver Equation string is: freesurf

FreeSurfaceSolver (freesurface): Velocity implicity (1=fully implicit)= 1.00

FreeSurfaceSolver (freesurface): No keyword > Apply Dirichlet < found. No limitation of solution

FreeSurfaceSolver (freesurface): Using horizontal ALE Formulation

FreeSurfaceSolver (freesurface): No Free Surface Orientation Vector found, assuming normal to z-axis

FreeSurfaceSolver (freesurface): Memory allocations done

FreeSurfaceSolver (freesurface): Non-linear Iteration 1 out of max. 20

FreeSurfaceSolver (freesurface): start assembly

ERROR:: FreeSurfaceSolver (freesurface): DIM=3 NSDOFs=3 does not combine. Aborting

Note: The following floating-point exceptions are signalling: IEEE_DENORMAL"

I found the source code of free surface solver but i don't know how to call/ define this orientation vector.. that is along y axis in my case! it is not the only problem probably but i need to fix each problem after the other! (i m not sure of my fluid flow boundary conditions but this is not the point).

I attach my sif file and mesh file generated with gmsh so run "ElmerGrid 14 2 cube.msh -relh 1.0 -3d -autoclean" but you certainly know better than me! Cheers for your help pals!

I have a new query about the free surface solver.

I tried to extend the case "free surface sloshing 2d" to a 3d one. Instead of a square (2d), i defined a cube geometry (0.4m).

And unfortunately, it did not work so easily! i applied my free surface on my top surface of my cube and just wanted to observe the oscillation of the surface under the gravity effect!

The free surface solver requires "Free surface Orientation Vector" but i don't know how to define this "normal vector"... i'm not quite sure that the computation stops because of that... here it is the end of the message:

"...

FlowSolve: -------------------------------------

FlowSolve: NAVIER-STOKES ITERATION 6

FlowSolve: -------------------------------------

FlowSolve:

FlowSolve: Starting Assembly...

FlowSolve: Assembly:

: ..Assembly done

DefUtils::DefaultDirichletBCs: Setting Dirichlet boundary conditions

DefUtils::DefaultDirichletBCs: Dirichlet boundary conditions set

FlowSolve: Dirichlet conditions done

CRS_IncompleteLU: ILU(0) (Real), Starting Factorization:

CRS_IncompleteLU: ILU(0) (Real), NOF nonzeros: 2042830

CRS_IncompleteLU: ILU(0) (Real), filling (%) : 100

CRS_IncompleteLU: ILU(0) (Real), Factorization ready at (s): 0.06

1 0.4771E-10

ComputeChange: NS (ITER=6) (NRM,RELC): ( 0.31160846E-02 0.34240129E-08 ) :: n-s

FlowSolve: iter: 6 Assembly: (s) 2.13 12.59

FlowSolve: iter: 6 Solve: (s) 0.11 0.80

FlowSolve: Result Norm : 3.1160846049305630E-003

FlowSolve: Relative Change : 3.4240129054564090E-009

SingleSolver: Attempting to call solver

SingleSolver: Solver Equation string is: freesurf

FreeSurfaceSolver (freesurface): Velocity implicity (1=fully implicit)= 1.00

FreeSurfaceSolver (freesurface): No keyword > Apply Dirichlet < found. No limitation of solution

FreeSurfaceSolver (freesurface): Using horizontal ALE Formulation

FreeSurfaceSolver (freesurface): No Free Surface Orientation Vector found, assuming normal to z-axis

FreeSurfaceSolver (freesurface): Memory allocations done

FreeSurfaceSolver (freesurface): Non-linear Iteration 1 out of max. 20

FreeSurfaceSolver (freesurface): start assembly

ERROR:: FreeSurfaceSolver (freesurface): DIM=3 NSDOFs=3 does not combine. Aborting

Note: The following floating-point exceptions are signalling: IEEE_DENORMAL"

I found the source code of free surface solver but i don't know how to call/ define this orientation vector.. that is along y axis in my case! it is not the only problem probably but i need to fix each problem after the other! (i m not sure of my fluid flow boundary conditions but this is not the point).

I attach my sif file and mesh file generated with gmsh so run "ElmerGrid 14 2 cube.msh -relh 1.0 -3d -autoclean" but you certainly know better than me! Cheers for your help pals!