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IDProjectCategoryView StatusDate SubmittedLast Update
0000335OpenFOAMBugpublic2011-11-10 00:222012-01-05 10:25
Reporteruser287Assigned Tohenry  
PriorityhighSeveritymajorReproducibilityalways
Status resolvedResolutionfixed 
PlatformLinuxOSFedoraOS VersionFedora 14
Summary0000335: 1D Pressure pulse propagation through the liquid/gas interface - compressibleInterFoam
DescriptionI have a 1D problem of pressure pulse propagation through the medium containing liquid/gas interface (Water/Air or Lead/Air). Pulse is set up to propagate in X-direction between 0<=X<=1. Boundary conditions are: At X=0: p_rgh - timeVaryingUniformFixedValue (shape and duration of the pulse); U- zeroGradient;
alpha=fixedValue, value uniform 1; At X=1: p_rgh - buoyantPressure; U - fixedValue, value (0 0 0), alpha - zeroGradient (rigid wall). In Y and Z directions 'empty' bc are specified. At t=0: uniform pressure 1e5 and uniform zero velocity are specified. VolumeFraction is setup to 1 (liquid phase water or lead) between 0<=X<=0.8 and to 0 (compressible gas phase air) for X>=0.8.
So pulse initially is supposed to run through the liquid and then at X=0.8 to hit the interface. Gravity is setup to zero in all directions.

TESTS:

1. Liquid - water Gas - air
Initial VOF and pressure pulse at t=0.0002 are shown on attached plots: InitialVOF_WaterAir_x=0.8.jpg and PressurePulse_t=2e-4_x=0.8_waterAir.jpg

All seems to work fine: Shape, propagation speed and amplitude of the pressure pulse are as expected.

2. Liquid - lead Gas - air
The only difference between this case and case 1 is increase in the density of the liquid by the factor of 10. (rho_water =1000, rho_o_water=1000; rho_lead=10000, rho_o_lead=10000)

Results at t=0.0002 are shown at InitialVOF_LeadAir_x=0.8.jpg and PressurePulse_t=2e-4_x=0.8_LeadAir.jpg. The shape of the pulse, amplitude and propagation speed exhibit very strange behaviour.

3. Liquid - lead Gas -air
This case is exactly the same as 2 but initially liquid occupies all the volume.
alpha =1 for 0<=X<=1. (In case 2, alpha=1 0<=X<=0.8, alpha=0 X>=0.8).
In this case pulse propagation is again seem to be correct (InitialVOF_LeadAir_x=0.8.jpg and PressurePulse_t=2e-4_LeadOnly.jpg).

So basically propagation of the pulse through the liquid part occurs to depend on the position of the interface and properties of the both fluids. This is very strange, as pulse is expected to 'learn' about existence of the interface only when it reaches it. I can't understand how initial position of the interface can affect pulse propagation characteristics through the liquid part far away from the interface.








 





 
Steps To Reproduce1. pulse shape and amplitude (piston_pressure):
 5
(
(0 1e5)
(0.00004 2e8)
(0.00007 2e8)
(0.0001 1e5)
(1 1e5)
)

2. transportProperties for water/air:
phase1
{
    transportModel Newtonian;
    nu nu [ 0 2 -1 0 0 0 0 ] 1e-6;
    rho rho [ 1 -3 0 0 0 0 0 ] 1000;
    rho0 rho0 [ 1 -3 0 0 0 0 0 ] 1000;
    psi psi [ 0 -2 2 0 0 ] 4.4e-7;
}

phase2
{
    transportModel Newtonian;
    nu nu [ 0 2 -1 0 0 0 0 ] 1.48e-5;
    rho rho [ 1 -3 0 0 0 0 0 ] 1;
    rho0 rho0 [ 1 -3 0 0 0 0 0 ] 0;
    psi psi [ 0 -2 2 0 0 ] 1e-5;
}

pMin pMin [ 1 -1 -2 0 0 0 0 ] 1e4;

sigma sigma [ 1 0 -2 0 0 0 0 ] 0.;

3. transportProperties (lead/air)
phase1
{
    transportModel Newtonian;
    nu nu [ 0 2 -1 0 0 0 0 ] 1e-6;
    rho rho [ 1 -3 0 0 0 0 0 ] 10000;
    rho0 rho0 [ 1 -3 0 0 0 0 0 ] 10000;
    psi psi [ 0 -2 2 0 0 ] 4.4e-7;
}

phase2
{
    transportModel Newtonian;
    nu nu [ 0 2 -1 0 0 0 0 ] 1.48e-5;
    rho rho [ 1 -3 0 0 0 0 0 ] 1;
    rho0 rho0 [ 1 -3 0 0 0 0 0 ] 0;
    psi psi [ 0 -2 2 0 0 ] 1e-5;
}

pMin pMin [ 1 -1 -2 0 0 0 0 ] 1e4;

sigma sigma [ 1 0 -2 0 0 0 0 ] 0.;


4. setFieldsDict - to setup initial VOF
defaultFieldValues
(
    volScalarFieldValue alpha1 1
// volScalarFieldValue p_rgh 1e5
);

regions
(
    boxToCell
    {
        box (0.8 0 -1) (1 1 1);
        fieldValues
        (
            volScalarFieldValue alpha1 0
        );
    }

);

5. controlDict
application compressibleInterFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 1e-3;

deltaT 5e-8;

writeControl timeStep; //adjustableRunTime; //timeStep;

writeInterval 400; //2.5e-5;

purgeWrite 0;

writeFormat binary;

writePrecision 6;

writeCompression uncompressed;

timeFormat general;

timePrecision 6;

runTimeModifiable yes;

adjustTimeStep no;


maxCo 0.25;

maxDeltaT 1;

6: 0 - directory

U:
dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
   topBottom
    {
        type empty;
    }
   left
    {
          type zeroGradient;
    }
   right
    {
          type zeroGradient;
    }

    frontBack
    {
        type empty;
    }
}

p_rgh:

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

internalField uniform 1e5;

boundaryField
{
   topBottom
    {
        type empty;
    }
    left
    {
      type timeVaryingUniformFixedValue;
      fileName "piston_pressure.dat";
      outOfBounds clamp;
    }
    frontBack
    {
        type empty;
    }
    right
    {
        type buoyantPressure;
    }
}

alpha1.org:

dimensions [0 0 0 0 0 0 0];

internalField uniform 1;

boundaryField
{
  topBottom
    {
        type empty;
    }

    right
    {
        type zeroGradient;
    }

   left
    {
        type fixedValue;
        value uniform 1;
    }

   frontBack
    {
        type empty;
    }
}
Additional InformationI have observed similar behaviour under certain conditions for 2D and 3D problems as well.

All directories needed to set up a case together with mentioned above plots are in attached 'TEST_1D_bug.tar'
TagsNo tags attached.

Activities

henry

2012-01-03 18:25

manager   ~0000893

Could you check how you attached TEST_1D_bug.tar, it doesn't appear to be present.

user287

2012-01-04 17:45

 

InitialVOF_LeadAir_x=0.8.jpg (46,890 bytes)   
InitialVOF_LeadAir_x=0.8.jpg (46,890 bytes)   

user287

2012-01-04 17:46

 

PressurePulse_t=2e-4_x=0.8_LeadAir.jpg (30,732 bytes)   
PressurePulse_t=2e-4_x=0.8_LeadAir.jpg (30,732 bytes)   

user287

2012-01-04 17:47

 

InitialVOF_WaterAir_x=0.8.jpg (46,261 bytes)   
InitialVOF_WaterAir_x=0.8.jpg (46,261 bytes)   

user287

2012-01-04 17:47

 

PressurePulse_t=2e-4_x=0.8_waterAir.jpg (47,272 bytes)   
PressurePulse_t=2e-4_x=0.8_waterAir.jpg (47,272 bytes)   

user287

2012-01-04 17:48

 

InitialVOF_LeadOnly.jpg (20,742 bytes)   
InitialVOF_LeadOnly.jpg (20,742 bytes)   

user287

2012-01-04 17:49

 

PressurePulse_t=2e-4_LeadOnly.jpg (45,943 bytes)   
PressurePulse_t=2e-4_LeadOnly.jpg (45,943 bytes)   

user287

2012-01-04 18:03

 

constant.tar (819,200 bytes)

user287

2012-01-04 18:04

 

0.tar (10,240 bytes)

user287

2012-01-04 18:05

 

system.tar (20,480 bytes)

user287

2012-01-04 18:05

 

piston_pressure.dat (64 bytes)

user287

2012-01-04 18:12

  ~0000897

A single file was too big, so I attached them one by one.

In directory 'constant' there are 2 files for transportProperties: 'transportProperties_leadAir' and 'transportProperties_waterAir'. These are to reproduce TEST_CASES described above. File 'piston_pressure.dat' defines shape of the pulse.

Thank you very much for looking into this,

Victoria

henry

2012-01-05 10:25

manager   ~0000898

Have you noticed that after a short time the pressure equation stops solving? This is because the tolerance you are setting for the pressure is not sufficiently low for this case. With a tighter tolerance it runs fine.

Issue History

Date Modified Username Field Change
2011-11-10 00:22 user287 New Issue
2012-01-03 18:25 henry Note Added: 0000893
2012-01-04 17:45 user287 File Added: InitialVOF_LeadAir_x=0.8.jpg
2012-01-04 17:46 user287 File Added: PressurePulse_t=2e-4_x=0.8_LeadAir.jpg
2012-01-04 17:47 user287 File Added: InitialVOF_WaterAir_x=0.8.jpg
2012-01-04 17:47 user287 File Added: PressurePulse_t=2e-4_x=0.8_waterAir.jpg
2012-01-04 17:48 user287 File Added: InitialVOF_LeadOnly.jpg
2012-01-04 17:49 user287 File Added: PressurePulse_t=2e-4_LeadOnly.jpg
2012-01-04 18:03 user287 File Added: constant.tar
2012-01-04 18:04 user287 File Added: 0.tar
2012-01-04 18:05 user287 File Added: system.tar
2012-01-04 18:05 user287 File Added: piston_pressure.dat
2012-01-04 18:12 user287 Note Added: 0000897
2012-01-05 10:25 henry Note Added: 0000898
2012-01-05 10:25 henry Status new => resolved
2012-01-05 10:25 henry Resolution open => fixed
2012-01-05 10:25 henry Assigned To => henry