[ms123]

Hello everyone!

I'm trying to simulate the oil flow in a gearbox. I'm using OpenFOAM 5.0. The oil starts suddenly after a few MILIseconds to go upwards. I've tried many simulations with different boundaries, but the problem does not disappear. I'm posting one example with it's boundaries and it's illustrated results as well.

If anyone knows how to avoid this unexplained behavior of the oil, please let me know.

Thanks a lot!

alpha.water

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0;

boundaryField
{
   Gehaeuse        { type     constantAlphaContactAngle;
                     theta0   25;
		     limit    gradient;
		     value    $internalField; }
  
   Symmetrieseite  { type     symmetryPlane;
                     value    $internalField; }
  
   Gearleft        { type     constantAlphaContactAngle;
                     theta0   25;
		     limit    gradient;
		     value    $internalField; }

   Gearright       { type     constantAlphaContactAngle;
                     theta0   25;
		     limit    gradient;
		     value    $internalField; } 
}

p_rgh

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

internalField   uniform 0;

boundaryField
{ Gehaeuse       { type zeroGradient;  }
  Symmetrieseite { type symmetryPlane; }
  Gearleft       { type zeroGradient;  }
  Gearright      { type zeroGradient;  }
}

pointMotion.U

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

internalField   uniform (0 0 0);

boundaryField
{ 
  Gehaeuse       
  {
                   type                  fixedValue;      
                   value                 $internalField;         
  }
  Symmetrieseite 
  { 
                   type                  slip;      
                   value                 $internalField;    
  }
  Gearleft       
  {               
                   type                  angularVelocity;  
                   axis                  (0 0 1);         
                   origin                (-0.075358 -0.07073 0.017); 
                   angle0                0.0;           
                   omega                 3.490658504; //2000rpm
                   value                 $internalField;
  }
  Gearright      
  { 
                   type                  angularVelocity;  
                   axis                  (0 0 -1);        
                   origin                (0.016142 -0.07073 0.017); 
                   angle0                0.0;       
                   omega                 3.490658504; //2000rpm  
                   value                 $internalField;
  }
  "procBoundary.*" { type processor; }		   
}

U

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

internalField   uniform (0 0 0);

boundaryField
{ Gehaeuse       { type fixedValue;            value $internalField; }
  Symmetrieseite { type symmetryPlane;         value $internalField; }
  Gearleft       { type movingWallVelocity;    value $internalField; }
  Gearright      { type movingWallVelocity;    value $internalField; }
}

1.png

2.png

3.png

[ms123]

As you can see, the problem appears only on the "symmetryPlane". (I've tried also the boundary "symmetry" and "symmetryPlane" in all fields, but the problem doesn't disappear.)