[rahulksoni]

Dear all
I am simulating the water flow through a screen (the screen which is a metal sheet with holes in it for the passage of fluid and/or particles).

Another similar post can be found at Flow being directed to one direction

Please refer to animation at https://www.dropbox.com/s/n2sc9nbgh9...ation.ogv?dl=0 or the attached snapshots.

The fluid flow has inlet velocity boundary condition from the top feeding area.
The left side is defined as a wall. The right and bottom opening are defined as the atmospheric boundary. It is a turbulent case with KOmegaSST model running with solver interFoam. The second phase in the system is ambient air. The front and back are the cyclic boundaries.

The velocity and pressure boundary conditions are as follows:
Velcoity

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

internalField	uniform (0.0 0.0 0.0);

boundaryField
{
	outlet
	{
		type			pressureInletOutletVelocity;
		inletValue		uniform (0.0 0.0 0.0);
		value			uniform (0.0 0.0 0.0);
		//type            inletOutlet;
        //inletValue      uniform (0 0 0);
        //value           uniform (0 0 0);
	}
	inlet
	{
		type			flowRateInletVelocity;
		value			uniform (0.0 0.0 0.0);
		volumetricFlowRate	constant 0.00207;//as per calculation in diary;//9.26E-6;
        //type            fixedValue;
        //value           uniform (0 0 -0.04655);
	}
	/*empty_walls
	{
		type			empty;
	}*/
	front
	{
		type 			cyclic;
	}
	back
	{
		type 			cyclic;
	}
	Screen_topBlockage
	{
		type			fixedValue;
		value			uniform (0.0 0.0 0.0);
	}
	Screen_VFinal
	{
		type			fixedValue;
		value			uniform (0.0 0.0 0.0);
	}
    left_wall
    {
		type			fixedValue;
		value			uniform (0.0 0.0 0.0);
    }		
}

Pressure

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

internalField	uniform 101325;

boundaryField
{
	outlet
	{
		type		totalPressure;
		p0			uniform 101325;
		rho			rho;
		phi			rhoPhi;
		gamma		0;
	}
	inlet
	{
		type		fixedFluxPressure;
		//type 		zeroGradient;
	}
	/*empty_walls
	{
		type		empty;
	}*/
	front
	{
		type 		cyclic;
	}
	back
	{	
		type 		cyclic;
	}
	Screen_topBlockage
	{
		type		fixedFluxPressure;
		//type		zeroGradient;
	}
	Screen_VFinal
	{
		type		fixedFluxPressure;
		//type		zeroGradient;
	}
    left_wall
    {
		type		fixedFluxPressure;
		//type		zeroGradient;
    }	
}

alpha.fluid

dimensions	[0 0 0 0 0 0 0];

internalField	uniform 0.0;

boundaryField
{
	outlet
	{
		type	zeroGradient;
		//type            inletOutlet;
        //inletValue      uniform 0;
        //value           uniform 0;
	}
	inlet
	{
		type	fixedValue;
		value	uniform 1.0;
	}
	/*empty_walls
	{
		type	empty;
	}*/
	front
	{
		type 	cyclic;
	}
	back
	{
		type 	cyclic;
	}
	Screen_topBlockage
	{
		type	zeroGradient;
	}
	Screen_VFinal
	{
		type	zeroGradient;
	}
	left_wall
	{
		type 	zeroGradient;
	}
}

Other boundary files are attached.
k.txt

omega.txt

nut.txt
Can anyone tell me why the fluid has the typical tendency to flow leftward where left plane is defined as a wall.

[rahulksoni]

I have looked into the flow profiles closely. And, I guess it is because of the significant density difference between water and air in interFoam.
Please see the attached screenshots. It shows that as the water touches the solid body (metal screen) there is a splash. Which causes to replace air by water in leftward and rightward of splash. However, due to small space in left region, there is significant water circulation flows. Air gets high velocity because of the low density of it while compared with water. This high speed flow creates low pressure in the region which attracts water there.
Someone, please comment.
Screenshot 2019-07-26 at 12.57.53 PM.jpg

Screenshot 2019-07-26 at 12.58.55 PM.jpg

[rahulksoni]

I could solve the problem by reducing block height on the left side. I guess due to the small region for movement on the left, the circulation of air occurred probably with high speed and that reduced the pressure in the region.
This made suck the fluid in the left region leading to the observed dynamics.

After reducing the height of the block at top or in other words by increasing the open area the problem was solved. Please see the attached snapshot.