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gradient of total pressure

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Old   June 22, 2011, 03:37
Default gradient of total pressure
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Gents,

I have a question regarding Paraview.
I would like to generate a variable "gradient of total pressure" from cell to cell (or node to node)
Has anyone experience with that?
I think this could be usefull to show, where in the system the biggest pressuredrops are placed.

Thanks for your help
Cheers,
Dito
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Old   August 2, 2011, 09:27
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Hi Dito,

I want to generate the same result. Did you find out how can paraview do that?

Regards,

Subhkirti.

Quote:
Originally Posted by DITO View Post
Gents,

I have a question regarding Paraview.
I would like to generate a variable "gradient of total pressure" from cell to cell (or node to node)
Has anyone experience with that?
I think this could be usefull to show, where in the system the biggest pressuredrops are placed.

Thanks for your help
Cheers,
Dito
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Old   August 3, 2011, 02:33
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Yes, this was easier as expected
There ist a standardfilter called "Gradient of unstructured Dataset" )
Just mark the Volume -> click on the filter and choose the variable from which you wanna create the gradients. -> In this case Ptot
Works fine.

Cheers
DITO
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Old   August 3, 2011, 04:13
Unhappy Gradient of Unstructured Datasets
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Thanks Dito,

I found the Gradient of Untrstructured Datasets yesterday, but I want not able to get to sensible results due to the following.

Quote:
Just mark the Volume
On switching to Volume view, my computer gets terribly slow, and does not generate a gradient field, which I saw being generated when it is in the surface mode. If by mark the volume, you mean just selecting the openfoam case, then it is ok. My computer configuration is quite good and a very recent one (2 core, 8GB RAM)

click on the filter and choose the variable from which you wanna create the gradients.
Quote:
-> In this case Ptot
Is it different from the pressure field. Mine has only p as the variable. Did you create Ptot from the normalised pressure fields in OpenFoam.
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Old   August 3, 2011, 04:38
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With switching the Geo Representation to volume, Paraview is doing s.th. like volume rendering. This needs a lot of recources.

With volume, I meant the volume in your pipeline browser.
Just mark it and click on the filter. Than select the specific variable.
Paraview will create a new part in your pipeline browser eg. GradientOfUnstructuredDataSet1.
This part, you can use as the source for clips, streamlines and so on.
The clip or streamline you can colour with the new gradient variable.

Reg. Ptot. this is an exported variable out of your solver. I think you forgot to export it.

I have also a question. maybe you have some experience with clipping.
I would like clip a specific section of my model with the planetool. Not the whole domain.
How can I do this? any Idea? And if it is possible, can I move the plane orthogonal to the plane Normal? I only managed to move it along the normal and resize the plane.

Thx
DITO
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Old   August 9, 2011, 06:23
Default Paraview clip filter
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Hi Dito,

Sorry for replying late. I did not understand your question fully, but it looks like you can use a box type in the clip filter to do that.

Quote:
Originally Posted by DITO View Post
With switching the Geo Representation to volume, Paraview is doing s.th. like volume rendering. This needs a lot of recources.

With volume, I meant the volume in your pipeline browser.
Just mark it and click on the filter. Than select the specific variable.
Paraview will create a new part in your pipeline browser eg. GradientOfUnstructuredDataSet1.
This part, you can use as the source for clips, streamlines and so on.
The clip or streamline you can colour with the new gradient variable.

Reg. Ptot. this is an exported variable out of your solver. I think you forgot to export it.

I have also a question. maybe you have some experience with clipping.
I would like clip a specific section of my model with the planetool. Not the whole domain.
How can I do this? any Idea? And if it is possible, can I move the plane orthogonal to the plane Normal? I only managed to move it along the normal and resize the plane.

Thx
DITO
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Old   August 9, 2011, 07:13
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thanks for reply.
no, this is not what I meant.
when you use the planetool, you clipping the whole volume of your geometry. This is not what I want.
I would like to create a clip not bigger as the planetool is. (implicit - explicit)

Did you manage to get your gradientcoloured Streamline?

DITO
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