[kareemm2]

Hey all,

I'm pretty new to OpenFOAM and I've been successfully running some (2D) simulations before this post. For this new simulation i'd like my inlet velocity to come in at 0.05 m/s at an angle of 45 degrees, I have given it a go but I'm not sure if what I'm trying to do is correct and I'd like someone to have a look at my U file (bellow) to either verify or suggest a way to accomplish this task.

Thanks.

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

internalField   uniform (0.0353 0.0353 0);

boundaryField
{
    ch1_inlet
    {
	type		inletOutlet;
        value           uniform (0.0353 0.0353 0);
	inletValue	uniform (0.0353 0.0353 0);
    }
    ch_1blocked
    {
	type		fixedValue;
        value           uniform (0 0 0);
    }
    ch1_wall
    {
	type		fixedValue;
        value           uniform (0 0 0);
    }
    ch1_to_porous
    {
        type            cyclic;
    }
    ch1_sides
    {
        type            empty;
    }
    ch2_blocked
    {
	type		fixedValue;
        value           uniform (0 0 0);
    }
    ch2_outlet
    {
        type            zeroGradient;
    }
    ch2_wall
    {
	type		fixedValue;
        value           uniform (0 0 0);
    }
    ch2_to_porous
    {
        type            cyclic;
    }
    ch2_sides
    {
        type            empty;
    }
    porous_ends
    {
	type		fixedValue;
        value           uniform (0 0 0);
    }
    porous_sides
    {
        type            empty;
    }
    porous_to_ch1
    {
        type            cyclic;
    }
    porous_to_ch2
    {
        type            cyclic;
    }
}

[usv001]

Hi there,

I am new to OF as well. As far as I know, there seems to be no problem with your BCs. You can always check if it's okay using Paraview before running.

Are you getting any sort of error when running it?

[kareemm2]

Hey, thanks for the reply, I've ran my simulation and there are no errors, I was just concerned that I may not have set up my U file to do what I wanted properly.

[Kina]

Quick reply: you're correct! Since you define U in components, your interpretation of the U file is right. You can also see it when you generate streamlines from the inlet in paraFoam.

Cheers
Alex

[kareemm2]

Thanks for the confirmation, but I forgot to ask; when changing the inlet velocity, was I right in changing the values internalfield, inletvalue and value for the velocity?

[kareemm2]

Nevermind; following Alex's advice, it seems that what I'm doing is fine. Thanks again for your help.

[Kina]

Yes, that's right.
I usually prefer to set my internalfield values to 0 at 0 and then initialize with potentialFoam. If you want to keep the intiial U for internalfield you can set the U for Inlet to

type             inletOutlet;
value            $internalField;
inletValue      $internalField;

this way, the inlet automatically accepts the internalfield value for 0 and you only have to change one number.

~~ what I was referring to when talking about the internalField at t=0 : this is only the initial velocity at t=0 and it changes anyway. From my experience , when dealing with complex geometry or high freestream turbulence, the convergence is a little softer when initializing with U = 0 for internalField.

Cheers
Alex

[kareemm2]

Thanks a bunch Alex, you've save me quite some time with that advice.