[Umut]

Hi everyone,

I’m currently working on a two-phase flow simulation using OpenFOAM's interFoam solver (a test case to learn two phase flow modelling). The case I'm modeling is a 2D laminar flow where water flows from a hole in a bottle. I used the damBreak tutorial as a base and set a fine, uniform mesh with 1 mm edge lengths. (Mesh image below)

The issue I'm facing is that the water jet gets partially reflected from the outlet, while I want the outlet to behave as atmosphere. The expected outcome was for the water jet to leave the domain smoothly, as if there was nothing at the outlet. Please see the video:

https://drive.google.com/file/d/1OKJ...ew?usp=sharing

I suspect the boundary conditions may not be properly set to allow for a smooth exit of the flow. Top surface on the left zone (bottle) is inletAir. Top, right, bottom surfaces of right zone (atmoshpere) is outletWater, all other boundaries are walls except frontAndBack.

Here are the boundary conditions I've used:

U:

boundaryField
{
    walls
    {
        type            noSlip;
    }

    outletWater
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }


    inletAir
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }

    frontAndBack
    {
        type            empty;
    }

}

alpha.water:

boundaryField
{
    walls
    {
        type            zeroGradient;
    }

    outletWater
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }


    inletAir
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }

    frontAndBack
    {
        type            empty;
    }
}

p_rgh:

boundaryField
{
    walls
    {
        type            fixedFluxPressure;
        value           uniform 0;
    }

    outletWater
    {
        type            totalPressure;
        p0              uniform 0;
    }


    inletAir
    {
        type            totalPressure;
        p0              uniform 0;
    }

    frontAndBack
    {
        type            empty;
    }

}

Mesh at the vicinity of the hole:
https://drive.google.com/file/d/1dH0...ew?usp=sharing