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Probe for X or Y velocity

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Old   September 11, 2009, 04:52
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santhosh
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Thanks for constant help, I could able to use in OF 1.6 as well now.
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Old   September 30, 2009, 17:37
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Nishant
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someone used the probes in OF 1.6. An example can be found in
\incompressible\pimpleFoam\t-junction\system

// Write at same frequency as fields
outputControl outputTime;
outputInterval 1;

there is new keyword word for the output control.

nishant

Last edited by nishant_hull; September 30, 2009 at 19:34.
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Old   September 28, 2011, 10:30
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Antonio Liggieri
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Hello,

does anybody know, how I can redirect the data from a probe also directly to the screen, so that I can plot them with the pyFoam utility? Is there any option to be switched on like "log = true" or something like that?

For any help thank you in advance

Kind regards,
Toni
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Old   September 29, 2011, 12:24
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Bernhard Gschaider
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Quote:
Originally Posted by alfa_8C View Post
Hello,

does anybody know, how I can redirect the data from a probe also directly to the screen, so that I can plot them with the pyFoam utility? Is there any option to be switched on like "log = true" or something like that?

For any help thank you in advance

Kind regards,
Toni
What you want is the value at one place on the standard-output so that a customRegexp can pick it up and plot it, right?

I'm afraid the probe-functionObject doesn't offer this (but I didn't research it too much)

What would be possible is to use (sorry) swak4Foam: generate a sampledSet of type cloud with one point. Use a functionObject swakExpression on it, set that to verbose and get that value. Maybe there is a simpler way.

To see how sampledSets are used in swak4Foam browse through the Examples that come with swak4Foam or look at my presentation from this years workshop

Bernhard
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Old   April 14, 2014, 03:40
Default Problem using multiple probe locations
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Sita Drost
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Hi all,

When I use multiple probe locations, only the data from the first location makes any sense, the rest gives values like -1e300. Does anyone have any experience with this? Ever seen this before?

My code looks like this:

functions
{
probes1
{
type probes;

functionObjectLibs ("libsampling.so");

region region0;

probeLocations
(
(1.3e-2 -2e-4 0)
(1.3e-2 0 0)
(1.3e-2 2e-4 0)
);

fields
(
U
);

outputControl timeStep;
outputInterval 100;
}
}


And I run the solver in parallel, on 4 cores (1 machine).

Thanks in advance for any help,

Sita

Additional info:
OpenFOAM gives warnings about these probe locations, it cannot find them:

--> FOAM Warning :
From function probes::read()
in file probes/probes.C at line 72
Did not find location (0.013 0 0) in any cell. Skipping location.
--> FOAM Warning :
From function probes::read()
in file probes/probes.C at line 72
Did not find location (0.013 0.0002 0) in any cell. Skipping location.

Strange, because both points are really present in my mesh...

Last edited by sita; April 14, 2014 at 07:25. Reason: Additional info
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Old   April 14, 2014, 19:34
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Bernhard Gschaider
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Quote:
Originally Posted by sita View Post
Hi all,

When I use multiple probe locations, only the data from the first location makes any sense, the rest gives values like -1e300. Does anyone have any experience with this? Ever seen this before?

<snip>


Additional info:
OpenFOAM gives warnings about these probe locations, it cannot find them:

--> FOAM Warning :
From function probes::read()
in file probes/probes.C at line 72
Did not find location (0.013 0 0) in any cell. Skipping location.
--> FOAM Warning :
From function probes::read()
in file probes/probes.C at line 72
Did not find location (0.013 0.0002 0) in any cell. Skipping location.

Strange, because both points are really present in my mesh...
-1e300 is the usual response if the probe is outside the mesh .... which OF very clearly points out to you in the warnings you quoted ("did not find in any cell")
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Old   April 15, 2014, 00:51
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Sita Drost
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Yeah, I know, that's pretty clear indeed. The only problem is, as I pointed out, that these points are really present in my mesh. In fact, they are in the list of vertices in blockMeshDict.

So maybe I should rephrase my question: why is OF unable to find these points? Is there something wrong with my syntax? Or does it have to do with the parallel solving? Or…?
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Old   April 15, 2014, 11:50
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Bernhard Gschaider
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Quote:
Originally Posted by sita View Post
Yeah, I know, that's pretty clear indeed. The only problem is, as I pointed out, that these points are really present in my mesh. In fact, they are in the list of vertices in blockMeshDict.

So maybe I should rephrase my question: why is OF unable to find these points? Is there something wrong with my syntax? Or does it have to do with the parallel solving? Or…?
Edges and corners are not a good idea. Testing for them is like dropping a ball onto a fence: you never know on which side it will fall (in your case: outside). Put the probe points SLIGHTLY inside (instead of 3 use 2.99999 for instance).
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Old   April 23, 2014, 02:04
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Thanks, that works!
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Old   July 22, 2015, 17:46
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António Pires
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Hello everyone,

I have a question regarding the probes function.

I'm modelling a wave flume with monochormatic waves propagating over it and i have applied the probes function to a series of points in the mesh to calculate velocity.

My question is: when i get the results ate the end of the run, those values of velocity are instantaneous velocity or are they phase averaged values?

I've been strugling with this for some time and maybe someone has the answer,

Thanks!

António
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