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Old   February 14, 2011, 10:12
Default groovyBC or parabolicVelocity + time
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Rickard
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Hi
I was trying to get the hang of groovyBc and the parabolic inlet velocity condition.
Im looking for an opinion on whether one or the other is better combined with a time restriction.
Putting it more clearly
At the moment I use timeVaryingUniformFixedValue with a ramp and outOfBounds clamp.
This is running okay, however I want to change the profile over the area so that it leaves my patch with a certain angle, 21.5degrees.
Can groovyBC and parabolic injection be combined with the time-extent? If so, how?
Appreciate the help!
R
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Old   February 14, 2011, 10:34
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Quote:
Originally Posted by Rickard.Solsjo View Post
Hi
I was trying to get the hang of groovyBc and the parabolic inlet velocity condition.
Im looking for an opinion on whether one or the other is better combined with a time restriction.
Putting it more clearly
At the moment I use timeVaryingUniformFixedValue with a ramp and outOfBounds clamp.
This is running okay, however I want to change the profile over the area so that it leaves my patch with a certain angle, 21.5degrees.
Can groovyBC and parabolic injection be combined with the time-extent? If so, how?
Appreciate the help!
R
Yep. Search for "timeline" on http://openfoamwiki.net/index.php/Contrib_groovyBC
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Old   February 14, 2011, 12:43
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Rickard
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Thx
this timeline would simply be e.g.
--> "name of timeLine file"
(t(start)
t2
.
.
.
t(end)
);
?
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Old   February 14, 2011, 13:22
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Bernhard Gschaider
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Quote:
Originally Posted by Rickard.Solsjo View Post
Thx
this timeline would simply be e.g.
--> "name of timeLine file"
(t(start)
t2
.
.
.
t(end)
);
?
It's the same format as for timeVaryingUniform. Have a look at the example case (groovyBC) that uses it

Bernhard
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Old   February 15, 2011, 04:16
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Ofc I looked at it. It says something about timevaryinguniform, however it only related to the "usual" conditions. I've been trying to find the original documentation of this without success. As I said above I've used timeVaryingUniformFixedValue before.
The only example of timelines at the contrib wiki are
timelines ();
or sth like
timelines (
file... impulse
...
);
without specifying the impulse input.
Thx
R
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Old   February 15, 2011, 05:20
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Bernhard Gschaider
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Quote:
Originally Posted by Rickard.Solsjo View Post
Ofc I looked at it. It says something about timevaryinguniform, however it only related to the "usual" conditions. I've been trying to find the original documentation of this without success. As I said above I've used timeVaryingUniformFixedValue before.
The only example of timelines at the contrib wiki are
timelines ();
or sth like
timelines (
file... impulse
...
);
without specifying the impulse input.
Thx
R
That is in the example files. If you feel it should be on the Wiki page feel free to extend it

Bernhard
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Old   February 15, 2011, 05:24
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I didn't mean to be disrespectful, groovyBC is a wonderful tool.
My only concern was that the timelines input wasn't extended enough, so I dont know what the input file looks like
Regards
R
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Old   February 15, 2011, 07:25
Default one more question..
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Mr GschaiderMay I ask yet another question.
At the moment I just have a mean velocity leaving the patch in the axial direction without any radial components.
I would like to create a boundary condition where the flow is leaving the patch at a certain angle relative to the center axis with a speed thats Ucos(theta) where U is the velocity where the angle theta=0.
My gridstructure is cartesian, so my question is if I have to calculate all of the x,y,z components or is multiplying a vector depending on the angle to the scalar velocity-value simply enough? Can groovyBC handle this?
I hope you understand my question
Regards
R
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Old   February 15, 2011, 08:30
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Quote:
Originally Posted by Rickard.Solsjo View Post
I didn't mean to be disrespectful, groovyBC is a wonderful tool.
My only concern was that the timelines input wasn't extended enough, so I dont know what the input file looks like
Regards
R
Not a problem.

Don't know how good groovyBC actually is (I'm biased) but its a lot better than the documentation

As you mentioned above that you'd already used timeVaryingUniform I assumed that you were familiar with the file format for those files

If you think that that the file should be on the Wiki page feel free to add it
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Old   February 15, 2011, 08:42
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Quote:
Originally Posted by Rickard.Solsjo View Post
Mr GschaiderMay I ask yet another question.
At the moment I just have a mean velocity leaving the patch in the axial direction without any radial components.
I would like to create a boundary condition where the flow is leaving the patch at a certain angle relative to the center axis with a speed thats Ucos(theta) where U is the velocity where the angle theta=0.
My gridstructure is cartesian, so my question is if I have to calculate all of the x,y,z components or is multiplying a vector depending on the angle to the scalar velocity-value simply enough? Can groovyBC handle this?
I hope you understand my question
Regards
R
I don't quite understand what you're trying to achive. But if it can be expressed with the usual vector operations (keep in mind that the operators & and ^ are inner and cross-product for vectors) then it can be done.

But I only help with problems with groovyBC. Not with vector arithmetics
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Old   February 15, 2011, 10:33
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so basically, it is something like this that i want to achieve

patch jet
{
type groovyBC;

variables: "Uz=150;rmax=0.0005;r=sqrt(pow(pos().x,2)+pow(pos( ).y,2));thetaMax=0.9825;theta=thetaMax*r/rmax";
"(r<=0.5) ? U=Uinlet:U=vector(0,0,0);" <-- is this included into the variables?

value: Uinlet="Uz*cos(theta)*vector(0,0,1)+Uz*sin(theta)* vector(0,1,0)*Uz*sin(theta)*vector(1,0,0):Uinlet=v ector(0,0,0)";

}

I appreciate the help
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