[heitorvitorc]

Dear community,


I'm using interFoam for a case concerning an oil droplet displacement through a micro-constricted capillar (constriction diameter ~225e-6 m). The case is developed as follows:


- Axissymmetric geometry;

- Velocity Driven Flow;
- Inlet Velocity (4e-4 0 0);
- Gravitational Effects Neglectable;
- Continuous Phase = Water (rho 1000kg/m³); Dispersed Phase = Oil (rho = 1328.8 kg/m³);
- Contact Angle is yet to define;

As a first analysis, I set up interfacial tension real low (72e-8 N/m), so I could see how the droplet would deform. After, I tried to increase sigma to its experimental value (sigma = 0,072 N/m), however, In this case the droplet doesnt deforms as I thought it would do. Instead, it suddenly jumps towards the wall and sticks right in the middle of the constriction. I'm still running the experiments, and havent had experimental contact angle yet, but I didnt expect this behavior.



Picture 1 (Start) is the initial phase fraction state, picture 2 (NoSigma) concerns to the simulation with neglectable interfacial tension, and picture 3 is the real deal (with sigma = 0,072 N/m). The alpha dicts are shown below.


I would really appreciate some help. Thanks in advance.


Best regards,


Vitor Cardoso


alpha dict

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 1;

boundaryField
{
    FrontAndBack
    {
        type            empty;
    }
    Inlet
    {
        type            fixedValue;
        value           uniform 1;
    }
    TopWall
    {
        type            zeroGradient;
    }
    Outlet
    {
        type            zeroGradient;
    }
    BottomWall
    {
        type            zeroGradient;
    }
    InnerWalls
    {
        type            zeroGradient;
    }
}

p_rgh dict

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

internalField   uniform 0;

boundaryField
{
    Inlet
    {
        type        zeroGradient;
    }

    Outlet
    {
        type        fixedValue;
        value        uniform 0;
    }

    TopWall
    {
    type        zeroGradient;
    }
    
    BottomWall
    {
    type        zeroGradient;
    }

    InnerWalls
    {
    type        zeroGradient;
    }
    
    FrontAndBack
    {
        type        empty;
    }

}

U dict

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

internalField   uniform (0 0 0);

boundaryField
{
    FrontAndBack
    {
        type            empty;
    }
    Inlet
    {
        //type            pressureInletVelocity;
    type        fixedValue;
        value           uniform (4e-4 0 0);
    }
    TopWall
    {
        type            noSlip;
    }
    Outlet
    {
        type            zeroGradient;
    }
    BottomWall
    {
        type            noSlip;
    }
    InnerWalls
    {
        type            noSlip;
    }
}

[Mikhail]

Hi!
I try to simulate similar process - can you share your geometry (blockMesh) ?