[Dr.Faustus]

Hi to everybody...
as i've wrote in another post i'm a rookie with open foam... so i've problems with very first steps...
now i'm trying to lounce a wigley-hull project
(i've followed this tutorial http://www.hydroniumion.de/general/s...mesh-tutorial/)

but it appears this error:

--> FOAM FATAL IO ERROR: 
cannot find file

file: /media/04095B560627AED8/tutorial_foam/wigley2/0/alpha1 at line 0.

    From function regIOobject::readStream()
    in file db/regIOobject/regIOobjectRead.C at line 73.

FOAM exiting

probably there's some mistakes in alpha1.org but i've checked it and found nothing strange except the version of openfoam (i've installed the last 2.1.1).
Any idea?
Thanks

[mgdenno]

Looks like it can't find your alpha1 file. Did you copy alpha1.org to alpha1 before running setFields?

[Dr.Faustus]

No sorry in fact now it's works... just erasing the .org extension.
thanks

[jhoepken]

Just a tip for the alpha1: Keep 0/alpha1.org and just copy it to 0/alpha1. Afterwards you may run setFields without any issues. You do not have to delete the nonuniform lists from 0/alpha1 if you change your mesh, since you have an untouched copy (0/alpha1.org) that you can just recopy again.

[Dr.Faustus]

Could you have a look to my alpha1 ? i've made some changes... but i'm not so conviced by the outlet properties... that in the default file i set as zeroGradient ()

i've setted the sides and the bottom as walls (the domain is quite large)

[Dr.Faustus]

There's something i've missed in my project as you can see in the image

something it's going better from last running but it seems to be still some mistake...
Now it's go to convergence (i've stopped near 10^-3)
but it seems there's some errors in inlet or U vector... seem that water came in from one side...

[SirWombat]

Where's the bottom in those files ?

[Dr.Faustus]

The mesh is oriented as in the reality: the first vertical face is the inlet (the opposite is the outlet) sides are parallel at the axe of the hull... The top orizontal plan is the atmosfear and the opposite is the bottom....

I've checked from blockmesh and the boundaries seems ok...
But from results it seems that's an opening in the bottom and the inleti is setted on side...
There's a way to visualize the boundaries?

[SirWombat]

ok, i had a look at the wigley-tutorial, where the bottom is defined together with the sides as a "symmetryPlane" in the "blockMeshDict". if you used the same setup that should be ok.

you did not post the boundary setup for "p_rgh". would be interesting to see what that looks like. the rest seems to be ok

The only thing i noticed is, that you set the velocity to stream from outlet to inlet: U_inlet=fixedValue;(-0.4 0 0). Be sure to have "p_rgh" defined accordingly!

Normally p would be "bouyantPressure" where the water comes in. And "zeroGradient" where the water leaves. in your case you will probably need the following setup ( just the opposite of what is defined in the wigley-hull tutorial):

p_rgh:

...

boundaryField
{
    outlet
    {
        type            buoyantPressure;
        value           uniform 0;
    }

    inlet
    {
        type            zeroGradient;
    }

...

Hope thats the clue here!

Greetings,
Jan

[Dr.Faustus]

Many thanks
In my p_rgh is exactly the opposite (it cames from tutorial)


anyway, sorry but i've to clarify some aspect:
the velocity vector is negative accordling with the direction of x of the reference system..
Ive tried to set it positively but comes out a floating point error...
maybe the velocity is to be setted positively and the floating point error is dued to another error

[Dr.Faustus]

Ok, i've solved the great part of the troubles...
now i can see something...

Now i've to improve the mesh.. that seems vary bad....
The last thing of solving i haven't understood is how i can predict the free survace level

[sail]

Ciao Ale.

to see the free surface level in paraview use the contour of VOF = 0.5. that will give you the free surface.

to see the height, on the same filter apply the calculator using z as the value.

let me know if you need further help.

[Dr.Faustus]

Ciao bello com'è?

I'm going to do some runs and let you know if it works
however i've to predict the height of free surface before running...
the model has no dof so i've to modify the mesh for having a fixed dept
maybe it's better to understand before how this solver calculates the free surface