[1988]

hello everyone
I am somehow new in openfoam please help me to solve the problem.
I have a simulated a pipe which water is flowing in and I am using icoFoam solver the check mesh is here

Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
    points:           96136
    faces:            267065
    internal faces:   246979
    cells:            85674
    faces per cell:   6
    boundary patches: 3
    point zones:      0
    face zones:       1
    cell zones:       1

Overall number of cells of each type:
    hexahedra:     85674
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     0

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
    Patch               Faces    Points   Surface topology                  
    body                19650    19700    ok (non-closed singly connected)  
    inlet               218      244      ok (non-closed singly connected)  
    outlet              218      244      ok (non-closed singly connected)  

Checking geometry...
    Overall domain bounding box (-0.0142294 0 -0.0151572) (0.0129588 0.0472016 0.0022)
    Mesh (non-empty, non-wedge) directions (1 1 1)
    Mesh (non-empty) directions (1 1 1)
    Boundary openness (8.88725e-17 9.11711e-17 1.4754e-17) OK.
    Max cell openness = 2.45267e-16 OK.
    Max aspect ratio = 5.50297 OK.
    Minimum face area = 5.30557e-09. Maximum face area = 1.31635e-07.  Face area magnitudes OK.
    Min volume = 1.66462e-12. Max volume = 3.77399e-11.  Total volume = 1.09182e-06.  Cell volumes OK.
    Mesh non-orthogonality Max: 20.6887 average: 5.3841
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 0.435615 OK.
    Coupled point location match (average 0) OK.

Mesh OK.

End

I can not understand why the solution is diverged and why the courant number suddenly explodes to unbelievable amounts.
here I put fvsolution and fv schemes

ddtSchemes
{
    default         Euler;
}

gradSchemes
{
    default         Gauss linear;
    grad(p)         Gauss linear;
}

divSchemes
{
    default         none;
    div(phi,U)      Gauss linear;
}

laplacianSchemes
{
    default         none;
    laplacian(nu,U) Gauss linear orthogonal;
    laplacian((1|A(U)),p) Gauss linear orthogonal;
}

interpolationSchemes
{
    default         linear;
    interpolate(HbyA) linear;
}

snGradSchemes
{
    default         orthogonal;
}

fluxRequired
{
    default         no;
    p               ;
}

solvers
{
    p
    {
        solver          PCG;
        preconditioner  DIC;
        tolerance       1e-06;
        relTol          0;
    }

    U
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-05;
        relTol          0;
    }
}

PISO
{
    nCorrectors     2;
    nNonOrthogonalCorrectors 2;
    pRefCell        0;
    pRefValue       0;
}

but this is courant numbers after just one time step(time steps are 0.001)

Time = 0.004

Courant Number mean: 2.82932e+17 max: 1.79062e+21

Is there any idea?