[boffin5]

Hi all,

For a long time I've been working on a case with a radiator in a duct, mounted on an airplane. An image is attached. Of late, I have been trying to use buoyantSimpleFoam to simulate it. As usual, I use tutorials for guidance, but I am finding that boundary conditions for the various tutorials are all over the map.

To construct the geometry, I used ennova, and the output was 2 meshes, one for the airplane/duct and the other for the heat exchanger. They were created simultaneously, therefore the meshes interface perfectly. In OpenFoam, I used mergeMesh to combine them, yielding 2 regions, and then stitchMesh to relate the faces at the radiator inlet and outlet faces, resulting in one region. Then I used topoSet to collect the radiator cells into a porous zone. Here is the output from topoSet:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = 0

Reading topoSetDict

Time = 0
    mesh not changed.
Created cellSet porousCells
    Applying source boxToCell
    Adding cells with center within boxes 1((2.02542 -0.22352 -0.64202) (2.08257 0 -0.47057))
    cellSet porousCells now size 4197
Created cellZoneSet porousZone
    Applying source setToCellZone
    Adding all cells from cellSet porousCells ...
    cellZoneSet porousZone now size 4197
End

In paraView, I click on 'Read zones' and 'Copy data to cell zones' to visualize the porous zone. But another way to do it is by this command: 'foamToVTK -cellSet porousZone', whereupon the output is:

Create time

Create mesh for time = 0

Keeping old VTK files in "/home/boffin5/cfdaero/meredith-buoyant-stitch/VTK"

--> FOAM FATAL ERROR: 
Problem

    From function void Foam::fvMeshSubset::setLargeCellSubset(const labelList&, Foam::label, Foam::label, bool)
    in file fvMeshSubset/fvMeshSubset.C at line 1172.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::fvMeshSubset::setLargeCellSubset(Foam::List<int> const&, int, int, bool) at ??:?

So I'm not sure what is going on. The output from checkMesh shows 1 highly skewed face; however this is not necessarily fatal, and I have edited the fvSchemes file to include 'skewCorrected' to account for the problem face.

Exec   : checkMesh

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
    points:           811893
    faces:            975893
    internal faces:   925868
    cells:            148777
    faces per cell:   12.7826
    boundary patches: 11
    point zones:      1
    face zones:       3
    cell zones:       1

Overall number of cells of each type:
    hexahedra:     1924
    prisms:        8
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     146845
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            5   4
            6   449
            7   3188
            8   5529
            9   10506
           10   14141
           11   16019
           12   15209
           13   18605
           14   20894
           15   15960
           16   11265
           17   7344
           18   3913
           19   2047
           20   904
           21   399
           22   191
           23   93
           24   63
           25   39
           26   22
           27   11
           28   10
           29   8
           30   3
           31   2
           32   2
           33   1
           34   2
           35   2
           36   3
           37   3
           39   1
           40   1
           41   1
           42   1
           43   2
           52   2
           54   1
           56   1
           66   1
           67   1
           83   1
           86   1

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
                    flap     5531    10013  ok (non-closed singly connected)
                fuselage     6860    14868  ok (non-closed singly connected)
                    lips     4865     7908  ok (non-closed singly connected)
                 fairing    20535    32634  ok (non-closed singly connected)
                 spinner      359      945  ok (non-closed singly connected)
            trailingedge      635      826  ok (non-closed singly connected)
                   edges     1640     2251  ok (non-closed singly connected)
                   inlet      135      272  ok (non-closed singly connected)
                  outlet      135      272  ok (non-closed singly connected)
                frontier     2317     4506  ok (non-closed singly connected)
                 clplane     6207    12369  ok (non-closed singly connected)

Checking geometry...
    Overall domain bounding box (-15 -7 -7) (50 3.98651e-09 7)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (-1.55353e-18 5.92364e-16 2.52647e-17) OK.
    Max cell openness = 3.46311e-16 OK.
    Max aspect ratio = 34.163 OK.
    Minimum face area = 5.32353e-10. Maximum face area = 1.18133.  Face area magnitudes OK.
    Min volume = 9.63107e-13. Max volume = 1.45954.  Total volume = 6368.32.  Cell volumes OK.
    Mesh non-orthogonality Max: 84.2436 average: 10.4766
   *Number of severely non-orthogonal (> 70 degrees) faces: 145.
    Non-orthogonality check OK.
  <<Writing 145 non-orthogonal faces to set nonOrthoFaces
    Face pyramids OK.
 ***Max skewness = 4.63047, 1 highly skew faces detected which may impair the quality of the results
  <<Writing 1 skew faces to set skewFaces
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.

End

Optimistically, I choose to believe that the porous zone cellZoneSet is okay, per the topoSet output. Now for the boundary conditions:

object      alphat;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -1 0 0 0 0];

//internalField   uniform 0;
internalField   uniform 1e-3;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            calculated;
        value           $internalField;
    }
    
    outlet
    {
        type            calculated;
        value           $internalField;
    }
    
    fuselage
    {
        type            compressible::alphatWallFunction;
        value           $internalField;
    }
    
    spinner
    {
        type            compressible::alphatWallFunction;
        value           $internalField;
    }
    
    lips
    {
        type            compressible::alphatWallFunction;
        value           $internalField;
    }
    
    fairing
    {
        type            compressible::alphatWallFunction;
        value           $internalField;
    }
    
    flap
    {
        type            compressible::alphatWallFunction;
        value           $internalField;
    }
   
    edges {
        type            compressible::alphatWallFunction;
        value           $internalField;
        }
    trailingedge {
        type            compressible::alphatWallFunction;
        value           $internalField;
        }
}

After 'fuselage' are the various pieces of the geometry that make up the model. For brevity I'll only show 'fuselage' for the remaining BCs.

object      epsilon;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -3 0 0 0 0];

//internalField   uniform 0.54;
internalField   uniform 200;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            turbulentMixingLengthDissipationRateInlet;
        mixingLength    0.005;
        value           uniform 200;    
     }
    
    outlet
    {
        type            inletOutlet;
        inletValue      $internalField;
        value           $internalField;
    }
    
    fuselage
    {
        type            epsilonWallFunction;
        value           $internalField;
    }

object      k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 1;    // 0.375

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            turbulentIntensityKineticEnergyInlet;
        intensity       0.05;
        value           uniform 1;
    }
    
    outlet
    {
        type            inletOutlet;
        inletValue      uniform 1;
        value           uniform 1;
    }
    
    fuselage
    {
        type            kqRWallFunction;
        value           uniform 1;
    }

object      nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -1 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            calculated;
        value           uniform 0;
    }
    
    outlet
    {
        type            calculated;
        value           uniform 0;
    }
    
    fuselage
    {
        type            nutkWallFunction;
        value           uniform 0;
    }

 object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 1e5;  //90812

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
       
    inlet
    {
        type            zeroGradient;
    }
    
    outlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    fuselage
    {
        type             zeroGradient;
    }

object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 1e5;  //84559

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            fixedFluxPressure;
        value           uniform 0;
     }
    
    outlet
    {
        type            prghPressure;
        p               uniform 1e5;
        value           uniform 1e5;
    }
    
    fuselage
    {
        type            fixedFluxPressure;
        value           uniform 0;
    }

 object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 282.214;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
        
    inlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    outlet
    {
        type            zeroGradient;
    }
    
    fuselage
    {
        type            zeroGradient;
    }

object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (59.161 0 0);

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            fixedValue;
        value           uniform (59.161 0 0);
    }
    
    outlet
    {
        type            zeroGradient;
     }
    
    fuselage
    {
        type            noSlip;
    }

Okay, now when I try to run it, it fails at the second time step:

Create time

Create mesh for time = 0


SIMPLE: Convergence criteria found
        p_rgh: tolerance 0.0001
        U: tolerance 1e-05
        e: tolerance 1e-05
        "(k|epsilon|omega)": tolerance 0.001

Reading thermophysical properties

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleEnthalpy;
}

Reading field U

Reading/calculating face flux field phi

Creating turbulence model

Selecting turbulence model type RAS
Selecting RAS turbulence model kEpsilon
RAS
{
    model           kEpsilon;
    turbulence      on;
    printCoeffs     on;
    Cmu             0.09;
    C1              1.44;
    C2              1.92;
    C3              0;
    sigmak          1;
    sigmaEps        1.3;
}

Creating thermophysical transport model

Selecting thermophysical transport type RAS
Selecting default RAS thermophysical transport model eddyDiffusivity

Reading g

Reading hRef
Calculating field g.h


Reading pRef
Reading field p_rgh

No MRF models present

Radiation model not active: radiationProperties not found
Selecting radiationModel none
Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type explicitPorositySource
    Source: porosity1
    - selecting cells using cellZone porousZone
    - selected 4197 cell(s) with volume 0.00219013
Porosity region porosity1:
    selecting model: DarcyForchheimer
    creating porous zone: porousZone

Starting time loop

Time = 0.25

smoothSolver:  Solving for Ux, Initial residual = 1, Final residual = 0.00181065, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 1, Final residual = 0.0963853, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 1, Final residual = 0.00167042, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 1, Final residual = 0.0197347, No Iterations 1
DICPCG:  Solving for p_rgh, Initial residual = 0.999649, Final residual = 0.00553735, No Iterations 95
time step continuity errors : sum local = 0.0254991, global = -1.95086e-05, cumulative = -1.95086e-05
smoothSolver:  Solving for epsilon, Initial residual = 0.586636, Final residual = 0.0554639, No Iterations 1
bounding epsilon, min: -704323 max: 612853 average: 458.189
smoothSolver:  Solving for k, Initial residual = 1, Final residual = 0.0828106, No Iterations 2
bounding k, min: -450.635 max: 413.426 average: 2.56551
ExecutionTime = 2.54 s  ClockTime = 2 s

Time = 0.5

smoothSolver:  Solving for Ux, Initial residual = 0.995391, Final residual = 6.33002e+237, No Iterations 1000
smoothSolver:  Solving for Uy, Initial residual = 0.999018, Final residual = 6.78445e+237, No Iterations 1000
smoothSolver:  Solving for Uz, Initial residual = 0.996324, Final residual = 7.79098e+237, No Iterations 1000
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/lib64/libc.so.6"
#3  void Foam::magSqr<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#4  Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::magSqr<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5  ? at ??:?
#6  __libc_start_main in "/lib64/libc.so.6"
#7  ? at /home/abuild/rpmbuild/BUILD/glibc-2.31/csu/../sysdeps/x86_64/start.S:122

My question is simply: I know there are problems with the BCs, but I need help to resolve them. Any and all guidance would be much appreciated!

[alexeym]

Hi,

Following your request, here are my thoughts on the case.

I think the problem is in IC/BC for turbulence, since after the first iteration we get:

smoothSolver:  Solving for epsilon, Initial residual = 0.586636, Final residual = 0.0554639, No Iterations 1
bounding epsilon, min: -704323 max: 612853 average: 458.189
smoothSolver:  Solving for k, Initial residual = 1, Final residual = 0.0828106, No Iterations 2
bounding k, min: -450.635 max: 413.426 average: 2.56551

Did you try other IC for turbulence (ex. start from 1e-16 instead of 200 and 1)?

BCs for pressure (p) should be calculated.

With this non-orthogonality I would suggest to increase number of non-orthogonal correctors.

What are your discretization schemes?

[boffin5]

I'm very encouraged to receive some support, and will run with your suggestions. Here is my fvSchemes file:
Odds are that you will have suggestions/revisions, and that is great!

object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         Euler;
}

gradSchemes
{
    default         Gauss linear;
}

divSchemes
{
    default         none;
    div(phi,U)      bounded Gauss upwind;
    div(phid,p)     bounded Gauss upwind;
    div(phiv,p)     bounded Gauss linear;
    div(phi,K)      bounded Gauss linear;
    div(phi,h)      bounded Gauss upwind;
    div(phi,e)      bounded Gauss upwind;
    div(phi,k)      bounded Gauss upwind;
    div(phi,epsilon) bounded Gauss upwind;
    div(phi,R)      bounded Gauss upwind;
    div(phi,omega)  bounded Gauss upwind;
    div((rho*R))    Gauss linear;
    div(R)          Gauss linear;
    div(U)          Gauss linear;
    div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear skewCorrected;
}

laplacianSchemes
{
    default         Gauss linear corrected;
}

interpolationSchemes
{
    default         linear skewCorrected;
}

snGradSchemes
{
    default         corrected;
}

Alan

[alexeym]

Your skewCorrected usage is not quite correct. See

incompressible/pimpleFoam/laminar/contaminatedDroplet2D/system/fvSchemes

for examples.

Gauss linear gradient reconstruction scheme can behave strangely on non-orthogonal meshes, use leastSquares instead. Example is in the same file.

Since your turbulence model diverges, try adding relaxation to k and epsilon equations. See

heatTransfer/buoyantBoussinesqSimpleFoam/iglooWithFridges/system/fvSolution

for example.

[boffin5]

Hi alexeym,

After incorporating your suggestions, I am still not having any luck. Always, the simulation fails at the start of time step 2, with this message:

Create time

Create mesh for time = 0


SIMPLE: Convergence criteria found
        p_rgh: tolerance 0.0001
        U: tolerance 1e-05
        e: tolerance 1e-05
        "(k|epsilon|omega)": tolerance 0.001

Reading thermophysical properties

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleEnthalpy;
}

Reading field U

Reading/calculating face flux field phi

Creating turbulence model

Selecting turbulence model type RAS
Selecting RAS turbulence model kEpsilon
bounding k, min: 1e-16 max: 1 average: 1e-16
RAS
{
    model           kEpsilon;
    turbulence      on;
    printCoeffs     on;
    Cmu             0.09;
    C1              1.44;
    C2              1.92;
    C3              0;
    sigmak          1;
    sigmaEps        1.3;
}

Creating thermophysical transport model

Selecting thermophysical transport type RAS
Selecting default RAS thermophysical transport model eddyDiffusivity

Reading g

Reading hRef
Calculating field g.h


Reading pRef
Reading field p_rgh

No MRF models present

Radiation model not active: radiationProperties not found
Selecting radiationModel none
Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type fixedTemperatureConstraint
    Source: source1
    - selecting cells using cellZone porousZone
    - selected 7832 cell(s) with volume 0.00219

Starting time loop

streamLine streamLines:
    automatic track length specified through number of sub cycles : 5

Reading surface description:
    yNormal

forces forceCoeffs1:
    Not including porosity effects
forceCoeffs forceCoeffs1:
    Not including porosity effects
streamLine streamLines write:
    seeded 60 particles
    Tracks:60
    Total samples:60
forceCoeffs forceCoeffs1 write:
    Cm    = 0.0234299
    Cd    = -0.19514
    Cl    = 0.000176957
    Cl(f) = 0.0235184
    Cl(r) = -0.0233414

Time = 1

DILUPBiCGStab:  Solving for Ux, Initial residual = 1, Final residual = 0.0171283, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 1, Final residual = 0.0112126, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 1, Final residual = 0.0105996, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.999996, Final residual = 0.0943934, No Iterations 7
DICPCG:  Solving for p_rgh, Initial residual = 0.999995, Final residual = 0.00815624, No Iterations 2
time step continuity errors : sum local = 39877.5, global = 3442.25, cumulative = 3442.25
DILUPBiCGStab:  Solving for epsilon, Initial residual = 0.996627, Final residual = 1.09285e-16, No Iterations 1
bounding epsilon, min: 5.11307e-18 max: 340.053 average: 56.4302
DILUPBiCGStab:  Solving for k, Initial residual = 1, Final residual = 6.80437e-11, No Iterations 1
bounding k, min: 2.9683e-17 max: 1 average: 4.40645e-09
ExecutionTime = 7.71 s  ClockTime = 8 s

Time = 2

DILUPBiCGStab:  Solving for Ux, Initial residual = 0.0498066, Final residual = 0.000245803, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.0945033, Final residual = 0.000519746, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.0954388, Final residual = 0.000618185, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99999, Final residual = 0.0989113, No Iterations 97


--> FOAM FATAL ERROR: 
Negative initial temperature T0: -8.74027e+06

    From function Foam::scalar Foam::species::thermo<Thermo,
 Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar
 (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar)
 const, Foam::scalar (Foam::species::thermo<Thermo, 
Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar
 (Foam::species::thermo<Thermo, 
Type>::*)(Foam::scalar) const, 
bool) const [with Thermo = Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; 
Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo
<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::
perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>]

It is failing, saying 'negative initial temperature.' This is despite my editing the porosityProperties file to add temperature limits:

porosity1
{
    type            DarcyForchheimer;

    cellZone        porousZone;
    
    // D 100;  // Very little blockage
    // D 200;  // Some blockage but steady flow
    // D 500;  // Slight waviness in the far wake
    // D 1000; // Fully shedding behavior

    d   (5e7 -1000 -1000);
    f   (0 0 0);

    coordinateSystem
    {
        type    cartesian;
        origin  (0 0 0);
        coordinateRotation
        {
            type    axesRotation;
            e1      (0 1 0);    
            e3      (0 0 1);    
        }
    }
    
    limitT
{
    type       limitTemperature;
    active    yes;
    
    selectionMode all;
    min        10;
    max        700;
    
}
}

Except for your suggestions, I have been using BCs from the angledDuct tutorial. Not sure if it matters, but there is one messy aspect of my case: I brought in the fuselage and radiator meshes individually from an outside mesher, then I used mergeMesh. There were common faces at the front and back face of the radiator, so I used stitchMesh to stitch them together (see attached image). This resulted in faces in polyMesh/boundary at the front and back of the radiator. I tried deleting them, but OpenFoam wouldn't let me. So in polyMesh/boundary I note them as 'patch' and in the BCs, I just denote those faces as 'slip'.

So everything is hanging now, and I don't know how to proceed. Again, I am hoping for help!

[alexeym]

If we take a look at the solver loop: it complains about negative temperatures after solution of the energy equation. More precisely, it happens in thermo.correct(), where OpenFOAM tries to calculate temperature from pressure and energy. This process is iterative (since we need to update thermophysical properties). If during these iterations negative temperature is encountered, the process is stoped with the error you see. Temperature limiting fvOption is not used at this stage, so it won't help here.

This iterative process uses new value of enthalpy and old value of pressure. So it your pressure on the previous solver iteration is strange or if new enthalpy is nonsense, temperature calculation fails.

Could you check pressure values (save data every time step)?

I assume you know what you are doing from physical point of view. We can use numerical tricks to make solution converge, yet it does not mean the solution is correct (or even meaningful).

[boffin5]

Hi alexeym, Thanks for continuing to help me!

Here is what I did to monitor the pressure; I hope it is what you were referring to:

I put in three probes: one in front of the radiator (0), one in the radiator itself (1) and one aft of the radiator (2). I specified the time step as 0.001. It fails immediately after time step 0.001:

# Probe 0 (1.428 -0.095 -0.625)
# Probe 1 (2.054 -0.095 -0.556)
# Probe 2 (2.544 -0.095 -0.518)
# Time              0                        1                            2                  
0                   90812                    90812                     90812              
0.001            90811.9954456       90811.8122094       90812.0142948

Here again is the run log:

Time = 0.002

DILUPBiCGStab:  Solving for Ux, Initial residual = 0.0498066423017, Final residual = 0.000245803139224, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.0945032705665, Final residual = 0.000519746009646, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.095438849419, Final residual = 0.000618184986078, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99998982141, Final residual = 0.099620289924, No Iterations 96


--> FOAM FATAL ERROR: 
Negative initial temperature T0: -8740269.93104

    From function Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, 
Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar 
(Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, 
Type>::*)(Foam::scalar) const, bool) const [with Thermo = Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; 
Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = 
Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>]
    in file /home/boffin5/OpenFOAM/OpenFOAM-8/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 56.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::
T(double, double, double, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, 
Foam::sensibleEnthalpy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::
perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::*)(double, double) const, double 
(Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::*)(double) const, bool) const at ??:?
#3  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::
hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::calculate() at ??:?
#4  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::
hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::correct() at ??:?
#5  ? at ??:?
#6  __libc_start_main in "/lib64/libc.so.6"
#7  ? at /home/abuild/rpmbuild/BUILD/glibc-2.31/csu/../sysdeps/x86_64/start.S:122

I would be over the moon if I could just get it to work!
But I can't do it without smart people such as you.

Alan

[alexeym]

In fact, what I meant:
- Set writeControl to timeStep, set writeInterval to 1.
- Run simulation.
- Open results in ParaView.

As an alternative you can use fieldMinMax function object to get minimum/maximum of a field and their locations.

This way you can see if there is a problem with pressure field.

Could you also post your fvSolution to see if there are problems with algorithm and linear solver settings.

[boffin5]

Hi alexeym,

Here is some debug information for you:
btw, I am using rhoPoroussimpleFoam as the solver, and OF8 as my OpenFoam version. Attached is an image of the p and T fields from paraView.

fvSolution:

object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p_rgh
    {
        solver          PCG;
        preconditioner  DIC;
        tolerance       1e-08;
        relTol          0.01;
    }

    "(U|e|h|k|epsilon)"
    {
        solver          PBiCGStab;
        preconditioner  DILU;
        tolerance       1e-05;
        relTol          0.1;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 0;

    pRefCell        0;
    pRefValue       0;

    residualControl
    {
        p_rgh           1e-4;
        U               1e-5;
        e               1e-5;

        // possibly check turbulence fields
        "(k|epsilon|omega)" 1e-3;
    }
}

relaxationFactors
{
    fields
    {
        p_rgh           0.7;
    }
    equations
    {
        U               0.3;
        e               0.5;
        "(k|epsilon|R)" 0.7;
    }
}

Here is the runlog showing the min/max values for p and T;

Create time

Create mesh for time = 0


SIMPLE: Convergence criteria found
        p_rgh: tolerance 0.0001
        U: tolerance 1e-05
        e: tolerance 1e-05
        "(k|epsilon|omega)": tolerance 0.001

Reading thermophysical properties

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleEnthalpy;
}

Reading field U

Reading/calculating face flux field phi

Creating turbulence model

Selecting turbulence model type RAS
Selecting RAS turbulence model kEpsilon
bounding k, min: 1e-16 max: 1 average: 1e-16
RAS
{
    model           kEpsilon;
    turbulence      on;
    printCoeffs     on;
    Cmu             0.09;
    C1              1.44;
    C2              1.92;
    C3              0;
    sigmak          1;
    sigmaEps        1.3;
}

Creating thermophysical transport model

Selecting thermophysical transport type RAS
Selecting default RAS thermophysical transport model eddyDiffusivity

Reading g

Reading hRef
Calculating field g.h


Reading pRef
Reading field p_rgh

No MRF models present

Radiation model not active: radiationProperties not found
Selecting radiationModel none
Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type fixedTemperatureConstraint
    Source: source1
    - selecting cells using cellZone porousZone
    - selected 7832 cell(s) with volume 0.00219

Starting time loop

streamLine streamLines:
    automatic track length specified through number of sub cycles : 5

Reading surface description:
    yNormal

forces forceCoeffs1:
    Not including porosity effects
forceCoeffs forceCoeffs1:
    Not including porosity effects
streamLine streamLines write:
    seeded 60 particles
    Tracks:60
    Total samples:60
forceCoeffs forceCoeffs1 write:
    Cm    = 0.0234299
    Cd    = -0.19514
    Cl    = 0.000176957
    Cl(f) = 0.0235184
    Cl(r) = -0.0233414

fieldMinMax FieldsMinMax write:
    min(p) = 90812 in cell 0 at location (2.69364 -0.128285 -0.543849)
    max(p) = 90812 in cell 0 at location (2.69364 -0.128285 -0.543849)
    min(T) = 282.214 in cell 0 at location (2.69364 -0.128285 -0.543849)
    max(T) = 282.214 in cell 0 at location (2.69364 -0.128285 -0.543849)

Time = 1

DILUPBiCGStab:  Solving for Ux, Initial residual = 1, Final residual = 0.0171283, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 1, Final residual = 0.0112126, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 1, Final residual = 0.0105996, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.999996, Final residual = 0.0943934, No Iterations 7
DICPCG:  Solving for p_rgh, Initial residual = 0.999995, Final residual = 0.00815624, No Iterations 2
time step continuity errors : sum local = 39877.5, global = 3442.25, cumulative = 3442.25
DILUPBiCGStab:  Solving for epsilon, Initial residual = 0.996627, Final residual = 1.09285e-16, No Iterations 1
bounding epsilon, min: 5.11307e-18 max: 340.053 average: 56.4302
DILUPBiCGStab:  Solving for k, Initial residual = 1, Final residual = 6.80437e-11, No Iterations 1
bounding k, min: 2.9683e-17 max: 1 average: 4.40645e-09
ExecutionTime = 10.57 s  ClockTime = 11 s

streamLine streamLines write:
    seeded 60 particles
    Tracks:60
    Total samples:42956
forceCoeffs forceCoeffs1 write:
    Cm    = 0.0353188
    Cd    = -0.191414
    Cl    = 0.0546054
    Cl(f) = 0.0626215
    Cl(r) = -0.0080161

fieldMinMax FieldsMinMax write:
    min(p) = -363633 in cell 47699 at location (48.6976 -2.14317 5.86476)
    max(p) = 1.98735e+06 in cell 301460 at location (49.2027 -3.57373 -2.92557)
    min(T) = -1.69207e+08 in cell 32536 at location (49.7342 -1.15187 -5.15114)
    max(T) = 1.31228e+08 in cell 34002 at location (49.7795 -6.56458 -2.87879)

Time = 2

DILUPBiCGStab:  Solving for Ux, Initial residual = 0.0498066, Final residual = 0.000245803, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.0945033, Final residual = 0.000519746, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.0954388, Final residual = 0.000618185, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99999, Final residual = 0.0989113, No Iterations 97


--> FOAM FATAL ERROR: 
Negative initial temperature T0: -8.74027e+06

And for completeness, here are my current BCs for p, p_rgh and T:
radiator-dom1 and radiator-dom2 are the faces on the front and back of the heat exchanger, and radwall is its surrounding faces. The side of the half-model is clplane, and the remainder of the domain bits are various pieces of the fuselage and fairing.

 object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 90812;  //84559

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
       
    inlet
    {
        type            zeroGradient;
    }
    
    outlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    fuselage
    {
        type             zeroGradient;
        
    }
    
    spinner
    {
        type             zeroGradient;
        
    }
    
    lips
    {
        type             zeroGradient;
        
    }
    
    fairing
    {
        type             zeroGradient;
        
    }
    
    flap
    {
        type             zeroGradient;
        
    }
    
    edges {
        type             zeroGradient;
        
        }
    trailingedge {
        type             zeroGradient;
        
        } 
        
    radiator-dom1
    {
        type             slip;
        
    }
    
    radiator-dom2
    {
        type             slip;
        
    }
    
    radwall
    {
        type             zeroGradient;
        
    } 
}

object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 1e5;  //84559

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            zeroGradient;
    }
    
    outlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    fuselage
    {
         type            zeroGradient;
    }
    
    spinner
    {
         type            zeroGradient;
    }
    
    lips
    {
         type            zeroGradient;
    }
    
    fairing
    {
         type            zeroGradient;
    }
    
    flap
    {
         type            zeroGradient;
    }
   
    edges {
         type            zeroGradient;
        }
    trailingedge {
         type            zeroGradient;
        }
        
    radiator-dom1
    {
        type             slip;
    }
    
    radiator-dom2
    {
        type             slip;
    }
    
    radwall
    {
         type            zeroGradient;
    }  
}

object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 282.214;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
        
    inlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    outlet
    {
        type            inletOutlet;
        value           $internalField;
        inletValue      $internalField;;
    }
    
    fuselage
    {
        type            zeroGradient;
    }
    
    spinner
    {
        type            zeroGradient;
    }
    
     lips
    {
        type            zeroGradient;
    }
    
     fairing
    {
        type            zeroGradient;
    }
    
     flap
    {
        type            zeroGradient;
    }

    edges {
        type zeroGradient;
        }
    trailingedge {
        type zeroGradient;
        } 
        
    radiator-dom1
    {
        type             slip;
    }
    
    radiator-dom2
    {
        type             slip;
    }
    
    radwall
    {
        type             zeroGradient;
    } 
}

I truly appreciate your taking time to help me in my struggle! And let me say that it has been monumental!

Alan

[alexeym]

So, after the first solver iteration you have strange pressure distribution and non-physical temperatures. I do not think it is worth doing second iteration.

1. As I said earlier, you should increase nNonOrthogonalCorrectors. With your mesh, it should be 1 or 2.
2. Relaxation: usually it is 0.3 for p_rgh, 0.7 for U. You do not solve equation for e but for h. So, you should relax h equation, not e.
3. Try starting from p_rgh == 0 and p == 1e5.

[boffin5]

Hi alexeym,

Per your guidance, I changed fvSolution:

object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p_rgh
    {
        solver          PCG;
        preconditioner  DIC;
        tolerance       1e-08;
        relTol          0.01;
    }

    "(U|e|h|k|epsilon)"
    {
        solver          PBiCGStab;
        preconditioner  DILU;
        tolerance       1e-05;
        relTol          0.1;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 2;

    pRefCell        0;
    pRefValue       0;

    residualControl
    {
        p_rgh           1e-4;
        U               1e-5;
        e               1e-5;

        // possibly check turbulence fields
        "(k|epsilon|omega)" 1e-3;
    }
}

relaxationFactors
{
    fields
    {
        p_rgh           0.3;    // 0.7
    }
    equations
    {
        U               0.7;    // 0.3
        //e               0.5;
        "(k|epsilon|R)" 0.7;
    }
}

And, p is now set to 1e15, and p_rgh is set at 0.

Now the run output reads:

fieldMinMax FieldsMinMax write:
    min(p) = 1e+15 in cell 0 at location (2.69364 -0.128285 -0.543849)
    max(p) = 1e+15 in cell 0 at location (2.69364 -0.128285 -0.543849)
    min(T) = 282.214 in cell 0 at location (2.69364 -0.128285 -0.543849)
    max(T) = 282.214 in cell 0 at location (2.69364 -0.128285 -0.543849)

Time = 1

DILUPBiCGStab:  Solving for Ux, Initial residual = 1, Final residual = 0.0314276, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 1, Final residual = 0.0703642, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 1, Final residual = 0.0660991, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 1, Final residual = 0.0956216, No Iterations 10

    From function Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, 
Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) 
const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, 
Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const, bool) const [with 
Thermo = Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; Type = Foam::sensibleEnthalpy; 
Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::
hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>]
    in file /home/boffin5/OpenFOAM/OpenFOAM-8/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 70
    Energy -> temperature conversion failed to converge:
          iter          Test           e/h          Cv/p          Tnew
             0       282.214      -16006.1        1004.4   3.72319e+19
             1   3.72319e+19   3.73957e+22        1004.4   3.72319e+19
             2   3.72319e+19   3.73957e+22        1004.4   3.72319e+19
             3   3.72319e+19   3.73957e+22        1004.4   3.72319e+19
             .  .  .  .  .  .  .  .  .  .  .  .  .  
            98   3.72319e+19   3.73957e+22        1004.4   3.72319e+19
            99   3.72319e+19   3.73957e+22        1004.4   3.72319e+19
           100   3.72319e+19   3.73957e+22        1004.4   3.72319e+19
           101   3.72319e+19   3.73957e+22        1004.4   3.72319e+19


--> FOAM FATAL ERROR: 
Maximum number of iterations exceeded: 100

    From function Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, 
Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, 
Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar 
(Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const, bool) const [with Thermo = 
Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; 
Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas
<Foam::specie> >, Foam::sensibleEnthalpy>]
    in file /home/boffin5/OpenFOAM/OpenFOAM-8/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 106.

FOAM aborting

It's interesting that Tnew and Test don't change after the first iteration.

I suppose that a useful conclusion can be drawn from this, but it is beyond me. Thank you for sticking with me!

[alexeym]

Why 1e15? 1 Gbar, I think it is a bit too much (higher than in the center of the earth). In my message it was 1 bar (1e5 Pa).

You do not see difference in temperature estimations in the output. Though, it does not matter, since value of 3e19 correspond to the pressure of 1e15, which is not quite applicable to your case.

[boffin5]

Hi alexeym,

After again getting run failures due to negative initial temperature, I have decided to try a different method of creating the mesh. I will get back to you again when I have finished creating a new mesh.

[boffin5]

Hi again alexeym,

Hoping against hope, I tweaked my mesh. Again, checkMesh shows 1 highly skewed face, which should not be a problem. And once again, it fails at timestep 2 with a negative initial temperature. I am not an expert at code writing, nor of gas thermodynamics, just a mere design engineer with an ME degree. So I am at a loss.

Here is the result from checkMesh:

Create time

Create polyMesh for time = constant

Time = constant

Mesh stats
    points:           1008475
    faces:            1227295
    internal faces:   1170370
    cells:            189473
    faces per cell:   12.6544
    boundary patches: 14
    point zones:      2
    face zones:       6
    cell zones:       1

Overall number of cells of each type:
    hexahedra:     2367
    prisms:        6
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     187100
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            6   422
            7   3990
            8   6932
            9   18727
           10   19267
           11   19434
           12   18490
           13   22607
           14   24645
           15   19330
           16   14196
           17   9003
           18   5055
           19   2647
           20   1206
           21   539
           22   220
           23   135
           24   82
           25   42
           26   34
           27   20
           28   16
           29   15
           30   4
           31   2
           32   12
           33   11
           34   3
           35   2
           36   1
           37   1
           38   3
           40   1
           42   1
           43   1
           44   1
           45   1
           47   1
           49   1

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
                    flap     5545    10036  ok (non-closed singly connected)
                fuselage     7200    15502  ok (non-closed singly connected)
                    lips     4832     7856  ok (non-closed singly connected)
                 fairing    24113    37463  ok (non-closed singly connected)
                 spinner      358      944  ok (non-closed singly connected)
            trailingedge      635      826  ok (non-closed singly connected)
                   edges     1624     2223  ok (non-closed singly connected)
                   inlet      135      272  ok (non-closed singly connected)
                  outlet      135      272  ok (non-closed singly connected)
                frontier     2317     4506  ok (non-closed singly connected)
                 clplane     6648    13238  ok (non-closed singly connected)
           radiator-dom2        0        0                        ok (empty)
           radiator-dom1        0        0                        ok (empty)
                 radwall     3383     4224  ok (non-closed singly connected)

Checking geometry...
    Overall domain bounding box (-15 -7 -7) (50 3.98651e-09 7)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (-3.62911e-18 4.01673e-16 1.60005e-17) OK.
    Max cell openness = 3.49772e-16 OK.
    Max aspect ratio = 29.8061 OK.
    Minimum face area = 2.51545e-10. Maximum face area = 1.18132.  Face area magnitudes OK.
    Min volume = 5.69978e-13. Max volume = 1.45954.  Total volume = 6368.32.  Cell volumes OK.
    Mesh non-orthogonality Max: 80.6191 average: 11.2348
   *Number of severely non-orthogonal (> 70 degrees) faces: 255.
    Non-orthogonality check OK.
  <<Writing 255 non-orthogonal faces to set nonOrthoFaces
    Face pyramids OK.
 ***Max skewness = 4.75385, 1 highly skew faces detected which may impair the quality of the results
  <<Writing 1 skew faces to set skewFaces
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.
End

And the result from the run log:

Create time

Create mesh for time = 0


SIMPLE: Convergence criteria found
        p: tolerance 0.001
        U: tolerance 0.0001
        e: tolerance 0.001
        "(k|epsilon|omega)": tolerance 0.001

Reading thermophysical properties

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleInternalEnergy;
}

Reading field U

Reading/calculating face flux field phi

Creating turbulence model

Selecting turbulence model type RAS
Selecting RAS turbulence model kEpsilon
bounding k, min: 1e-16 max: 1 average: 1e-16
RAS
{
    model           kEpsilon;
    turbulence      on;
    printCoeffs     on;
    Cmu             0.09;
    C1              1.44;
    C2              1.92;
    C3              0;
    sigmak          1;
    sigmaEps        1.3;
}

Creating thermophysical transport model

Selecting thermophysical transport type RAS
Selecting default RAS thermophysical transport model eddyDiffusivity

Reading g

Reading hRef
Calculating field g.h


Reading pRef
Reading field p_rgh

pressureControl
    pMax 200000
    pMin 50000

No MRF models present

Radiation model not active: radiationProperties not found
Selecting radiationModel none
Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type fixedTemperatureConstraint
    Source: source1
    - selecting cells using cellZone porousZone
    - selected 23787 cell(s) with volume 0.00219013

Starting time loop

streamLine streamLines:
    automatic track length specified through number of sub cycles : 5

--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 80806, 5(100465 100500 100501 100509 100467), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 138440, 6(161307 161306 162010 162011 162008 162007), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 141308, 6(164050 164049 164710 164711 164712 164713), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 142054, 6(164713 164712 165365 165366 165367 165368), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 144795, 6(167137 167136 167751 167752 167753 167754), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 145498, 6(167730 167731 168356 168357 168358 168359), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 146081, 6(168262 168261 168867 168868 168869 168870), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 146101, 6(168292 168293 168884 168885 168886 168887), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 146743, 5(168857 168858 169453 169454 169451), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 147681, 6(169610 169609 170256 170257 170258 170259), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 148330, 5(170240 170241 170829 170827 170825), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 149713, 6(171394 171395 172016 172017 172018 172019), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 150514, 6(172706 172708 172709 172710 172711 172707), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 151060, 4(173195 173194 173196 173197), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 154552, 6(175656 175655 176232 176233 176230 176229), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 154583, 6(175683 175682 176256 176257 176258 176259), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 155404, 5(176954 176953 176952 176957 176955), produces a valid tet decomposition.
--> FOAM Warning : 
    From function Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 76
    No base point for face 158175, 6(178834 178835 179504 179505 179506 179507), produces a valid tet decomposition.
Reading surface description:
    yNormal

forces forceCoeffs1:
    Not including porosity effects
forceCoeffs forceCoeffs1:
    Not including porosity effects
streamLine streamLines write:
    seeded 60 particles
    Tracks:60
    Total samples:60
forceCoeffs forceCoeffs1 write:
    Cm    = 0.0127246
    Cd    = -0.000195089
    Cl    = 0.000194975
    Cl(f) = 0.0128221
    Cl(r) = -0.0126272

fieldMinMax FieldsMinMax write:
    min(p) = 100000 in cell 0 at location (2.76951 -0.136111 -0.562052)
    max(p) = 100000 in cell 0 at location (2.76951 -0.136111 -0.562052)
    min(T) = 282.214 in cell 0 at location (2.76951 -0.136111 -0.562052)
    max(T) = 282.214 in cell 0 at location (2.76951 -0.136111 -0.562052)

Time = 1

DILUPBiCGStab:  Solving for Ux, Initial residual = 1, Final residual = 0.0273403, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 1, Final residual = 0.0740393, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 1, Final residual = 0.0287669, No Iterations 1
smoothSolver:  Solving for e, Initial residual = 0.999999, Final residual = 0.0879115, No Iterations 6
DICPCG:  Solving for p_rgh, Initial residual = 0.999482, Final residual = 0.000610146, No Iterations 1
DICPCG:  Solving for p_rgh, Initial residual = 0.00256748, Final residual = 2.1228e-05, No Iterations 1
DICPCG:  Solving for p_rgh, Initial residual = 9.50824e-05, Final residual = 7.98586e-07, No Iterations 190
time step continuity errors : sum local = 94.4224, global = -2.21546, cumulative = -2.21546
pressureControl: p max 3.74934e+06
pressureControl: p min -803987
smoothSolver:  Solving for epsilon, Initial residual = 0.999497, Final residual = 1.44467e-16, No Iterations 2
bounding epsilon, min: 1.04376e-17 max: 380.001 average: 15.2023
smoothSolver:  Solving for k, Initial residual = 1, Final residual = 4.47558e-10, No Iterations 2
bounding k, min: 2.20827e-17 max: 1 average: 6.27641e-08
ExecutionTime = 8.76 s  ClockTime = 9 s

streamLine streamLines write:
    seeded 60 particles
    Tracks:60
    Total samples:17052
forceCoeffs forceCoeffs1 write:
    Cm    = 0.83455
    Cd    = 36.2825
    Cl    = 0.206268
    Cl(f) = 0.937684
    Cl(r) = -0.731417

fieldMinMax FieldsMinMax write:
    min(p) = 50000 in cell 36 at location (49.8046 -6.80455 -6.81129)
    max(p) = 200000 in cell 0 at location (2.76951 -0.136111 -0.562052)
    min(T) = -2.49422e+08 in cell 13287 at location (49.7648 -2.5124 6.05812)
    max(T) = 6.34698e+08 in cell 13306 at location (49.7763 -5.26952 0.942598)

Time = 2

DILUPBiCGStab:  Solving for Ux, Initial residual = 0.137064, Final residual = 0.00352126, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.192966, Final residual = 0.00250268, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.125257, Final residual = 0.00255952, No Iterations 1
smoothSolver:  Solving for e, Initial residual = 1, Final residual = 0.05108, No Iterations 1


--> FOAM FATAL ERROR: 
Negative initial temperature T0: -6.34971e+06

    From function Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const, bool) const [with Thermo = Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; Type = Foam::sensibleInternalEnergy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>]
    in file /home/boffin5/OpenFOAM/OpenFOAM-8/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 56.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::T(double, double, double, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double) const, bool) const at ??:?
#3  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::calculate() at ??:?
#4  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::correct() at ??:?
#5  ? at ??:?
#6  __libc_start_main in "/lib64/libc.so.6"
#7  ? at /home/abuild/rpmbuild/BUILD/glibc-2.31/csu/../sysdeps/x86_64/start.S:122

The runlog is full of moans from OpenFoam about base points, but that should't matter.

Should you or anyone else have a few minutes and a philanthropic urge, I have placed the case files into this dropbox location for review:
https://www.dropbox.com/scl/fi/gxq5l...=fsu55q19&dl=0

Often in this forum, I have seen queries from FSAE or Formula Student teams seeking assistance in their design of a heat exchanger for their car, but I haven't seen any substantive answers. And the thermal engineering journals are bursting with papers from researchers who have done this kind of analysis, but the case files are never available. If you know of any, please forward!

[boffin5]

Hi alexeym,

Prior to trying to solve my case with buoyantSimpleFoam, I had been using chtMultiRegionFoam with a 2 region version. Although it ran to completion, the fields as seen in paraView had problems. Please see the attached image; there are crazy problems, especially in the T field. So I decided to change my approach. However, it seems that the multiRegion case is closer to a satisfactory resolution, so I would be indebted to you if you can stick with me and give advice as to how I can fix it.

In hopes that you will spot something obvious, I will list below the boundary conditions for pressure and temperature for both fluid and solid. However, the entire case can be found in this dropbox link:
https://www.dropbox.com/scl/fi/xnib9...=3uc3edu4&dl=0

I have been working on this case for awfully long time, but I will not surrender! Perhaps you can help put me out of my misery.

In the following, 'radiator-interface' is the set of faces on the periphery of the radiator. For brevity, I will only show all the geometry features in the first BC.
fluid alphat:

object      alphat;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -1 0 0 0 0];

internalField   uniform 1e-3;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            calculated;
        value           uniform 0;
    }
    
    outlet
    {
        type            calculated;
        value           uniform 0;
    }
    
    fuselage
    {
        type            compressible::alphatWallFunction;
        value           uniform 0;
    }
    
    spinner
    {
        type            compressible::alphatWallFunction;
        value           uniform 0;
    }
    lips
    {
        type            compressible::alphatWallFunction;
        value           uniform 0;
    }
    
    fairing
    {
        type            compressible::alphatWallFunction;
        value           uniform 0;
    }
    
    flap
    {
        type            compressible::alphatWallFunction;
        value           uniform 0;
    }
    
    radiator-interface {
        type            compressible::alphatWallFunction;
        value           uniform 0;
        }
    edges {
        type            compressible::alphatWallFunction;
        value           uniform 0;
        }
    trailingedge {
        type            compressible::alphatWallFunction;
        value           uniform 0;
        }
}

fluid epsilon:

 object      epsilon;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -3 0 0 0 0];

//internalField   uniform 0.54;
internalField   uniform 200;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        //type            zeroGradient;
        type            slip;
    }
    
    inlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    outlet
    {
        type            zeroGradient;
    }
    
    fuselage
    {
        type            epsilonWallFunction;
        value           $internalField;
    }

fluid k:

object      k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 0.375;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    outlet
    {
        type            zeroGradient;
    }
    
    fuselage
    {
        type            kqRWallFunction;
        value           $internalField;
    }

fluid nut:

 object      nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -1 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
     }
    
    inlet
    {
        type            calculated;
        value           uniform 0;
    }
    
    outlet
    {
        type            calculated;
       value           uniform 0;
    }
    
    fuselage
    {
        type            nutkWallFunction;
        value           uniform 0;
    }

fluid p:

 object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 90812;  

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
       
    inlet
    {
        type            zeroGradient;
    }
    
    outlet
    {
        type            fixedValue;
        value           uniform 90812;
    }
    
    fuselage
    {
        type             zeroGradient;
     }

fluid p_rgh:

 object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 1e5;  

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            zeroGradient;
     }
    
    outlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    fuselage
    {
         type            zeroGradient;
    }

fluid T:

object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 282.214;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
         type            slip;
    }
        
    inlet
    {
        type            fixedValue;
        value           uniform 282.214;
    }
    
    outlet
    {
        type            inletOutlet;
        inletValue      uniform 282.214;
        value           uniform 282.214;
    }
    
    fuselage
    {
        type            zeroGradient;
    }

fluid U:

 object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (59.161 0 0);

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            fixedValue;
        value           uniform (59.161 0 0);
    }
    
    outlet
    {
        type            inletOutlet;
        inletValue      uniform (0 0 0);
        value           uniform (0 0 0);
    }
    
    fuselage
    {
        type            noSlip;
    }

And now for solid p
(rad_radinlet and rad_rad_outlet are the front and back faces of the radiator, and rad_radfrontier is the set of peripheral faces):

object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 90812;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
        
    inlet
    {
        type            zeroGradient;
     }
    
    outlet
    {
        type            fixedValue;
        value           uniform 90812;
    }
      
    
     rad_radinlet
    {
        type            calculated;
        value           uniform 90812;
    }
    
    rad_radoutlet
    {
        type            calculated;
        value           uniform 90812;
    }

    rad_radfrontier
    {
        type            calculated;
        value           uniform 90812;
     }
       
    "proc.*"
    {
        type processor;
    }    
}

solid p_rgh:

 object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 1e05;  

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
        
    inlet
    {
        type            fixedFluxPressure;
     }
    
    outlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    
    rad_radinlet
    {
        type            fixedFluxPressure;
     }
    
    rad_radoutlet
    {
        type            fixedValue;
        value           $internalField;
    }

    rad_radfrontier
    {
        type            fixedFluxPressure;
     }

solid T:

object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 377.59;

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
        
    inlet
    {
        type            fixedValue;
        value           uniform 377.59;
    }
    
    outlet
    {
        type            inletOutlet;
        inletValue      uniform 376;    
        value           uniform 376;    
    }
    
   
    rad_radinlet
    {
        type            fixedValue;
        value           $internalField;
    }
    
    rad_radoutlet
    {
        type            inletOutlet;
        inletValue      $internalField;
        value           $internalField;
    }

    rad_radfrontier
    {
        type            zeroGradient;
    }

and lastly, solid U:

 object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

//internalField   uniform (10 0 0);
internalField   uniform (0.01 0 0);

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    frontier
    {
        type            slip;
    }
        
    inlet
    {
        type            fixedValue;
        value           uniform (0.01 0 0);
    }
    
    outlet
    {
        type            inletOutlet;
        inletValue      uniform (0 0 0);
        value           uniform (0 0 0);
    }   
    
    rad_radinlet
    {
        type            fixedValue;
        value           uniform (0.01 0 0);
    }
    
    rad_radoutlet
    {
        type            inletOutlet;
        inletValue      uniform (0 0 0);
        value           uniform (0 0 0);
    }

    rad_radfrontier
    {
        type            noSlip;
    }

[boffin5]

After discovering that my controlDict listed the wrong solver, I changed it to rhoPorousSimpleFoam, and the simulation ran to completion! But I knew it was too good to be true.

It turns out that U was set to zero, one of those changes one makes in efforts to debug. When I set it to a realistic value, the simulation, yet once again, failed with a negative initial temperature.

Back to square zero. All my previous questions still apply. Sigh!

[boffin5]

In hopes that someone can help me make sense of debugging results from my rhoPorousSimpleFoam simulation of a heat exchanger, and perhaps help me get to the Promised Land, I am showing some paraView images.

I found that the case would fail with a floating point exception, and a search into this excellent forum found that I could bypass the failure by adding "unset FOAM_SIGFPE" to the run script. Then I could note at which time step the failure occured, and edit the endTime to look at the results prior to the failure.

The attached image shows the results at velocities of 1.0, and then 59.16 which is my design point. At U = 1 the p and U fields look psychedelic; at least the radiator color is reasonable.

It seems that the higher the velocity, the sooner the case fails. At U =59.16 it failed at timeStep 13. The p and T fields went crazy, but at least the U field shows some velocity within the duct. However, at the inlet, it shows the velocity as 0.0017, whereas my BC has it at 59.16. Apparently my BC for U is wrong; here it is:

object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (59.161 0 0);    // (59.161 0 0)

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"
    
    clplane
    {
        type            slip;
    }
    
    frontier
    {
        type            slip;
    }
    
    inlet
    {
        type            flowRateInletVelocity;
        massFlowRate    constant 0.1;
        rhoInlet        1; 
        value           uniform (59.161 0 0);

        //type            fixedValue;
        //value           uniform (59.161 0 0);
    }
    
    outlet
    {
        //type            inletOutlet;
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
        inletValue      uniform (0 0 0);
        //type            zeroGradient;
    }
    
    fuselage
    {
        type            noSlip;
    }
    
    spinner
    {
        type            noSlip;
    }
    
    lips
    {
        type            noSlip;
    }
    
    fairing
    {
        type            noSlip;
    }
    
    flap
    {
        type            noSlip;
    }
      
    edges {
        type noSlip;
        }
    trailingedge {
        type noSlip;
        }
        
    radiator-dom1
    {
        type             slip;
    }
    
    radiator-dom2
    {
        type             slip;
    }
    
    radwall
    {
        type            noSlip;
    } 
}

Although I have tried various formats for the U boundary condition, it still fails.

I would be utterly grateful for any help I might receive with this!