# Can PyFR output the solution on the bounraries?

**URL:** <https://pyfr.discourse.group/t/can-pyfr-output-the-solution-on-the-bounraries/95>\
**Category:** General\
**Created:** [23 November 2015 12:53 UTC](https://pyfr.discourse.group/t/can-pyfr-output-the-solution-on-the-bounraries/95 "2015-11-23T12:53:06Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Antonio\_Garcia-Uceda](https://avatars.discourse-cdn.com/v4/letter/a/ce73a5/32.png) [@Antonio\_Garcia-Uceda](https://pyfr.discourse.group/u/Antonio_Garcia-Uceda)\
**Post date:** [23 November 2015 12:53 UTC](https://pyfr.discourse.group/t/can-pyfr-output-the-solution-on-the-bounraries/95/1 "2015-11-23T12:53:06Z")

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Dear all,

I’d like to ask you whether PyFR is able to output the solution on specific boundaries, such as pressure on a solid boundary.

I know with the “[soln-plugin-sampler]” one can output the solution at specific locations, but it’d be tedious to define the boudnary point by point.

If there’s not such capability in PyFR, Could you please tell me how you normally do it? Perhaps directly in Paraview?

Thanks in advance

Best regards,  
Antonio

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**Author:** ![fdw](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@fdw](https://pyfr.discourse.group/u/fdw)\
**Post date:** [23 November 2015 13:12 UTC](https://pyfr.discourse.group/t/can-pyfr-output-the-solution-on-the-bounraries/95/2 "2015-11-23T13:12:13Z")

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Hi Antonio,

> I'd like to ask you whether PyFR is able to output the solution on  
> specific boundaries, such as pressure on a solid boundary.
> 
> I know with the "[soln-plugin-sampler]" one can output the solution  
> at specific locations, but it'd be tedious to define the boudnary  
> point by point.
> 
> If there's not such capability in PyFR, Could you please tell me  
> how you normally do it? Perhaps directly in Paraview?

It depends what you wish to do with the pressure on the boundary.  
PyFR has a [soln-plugin-fluidforce] plugin that can integrate up  
forces (pressure + viscous) on a given boundary. This may be what  
you're looking for.

Currently, however, dumping the raw data on a boundary is not  
possible. It should be possible to accomplish this using a plugin,  
though. For the moment the easiest -- although not necessarily the  
most efficient -- solution is to dump out the entire volume and then  
use ParaView to obtain the solution on the boundaries of interest.

Regards, Freddie.

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**Author:** ![Antonio\_Garcia-Uceda](https://avatars.discourse-cdn.com/v4/letter/a/ce73a5/32.png) [@Antonio\_Garcia-Uceda](https://pyfr.discourse.group/u/Antonio_Garcia-Uceda)\
**Post date:** [23 November 2015 16:34 UTC](https://pyfr.discourse.group/t/can-pyfr-output-the-solution-on-the-bounraries/95/3 "2015-11-23T16:34:46Z")

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Hi Freddie,

Thanks a lot for the reply.

Indeed I was looking to output the Cp profile on the solid boundary. I think I’ll need to use paraview for that.

Perhaps you or any of your colleagues know how to output a given quantity on the boundaries in paraview?

Thanks once more.

Best regards,  
Antonio

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**Author:** ![fdw](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@fdw](https://pyfr.discourse.group/u/fdw)\
**Post date:** [23 November 2015 16:40 UTC](https://pyfr.discourse.group/t/can-pyfr-output-the-solution-on-the-bounraries/95/4 "2015-11-23T16:40:36Z")

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Hi Antonio,

It should not be too hard to write a plugin to accomplish this.  
However, PyFR does not currently have a standardised format for  
writing out data on boundaries to disk (unlike for volume data).

Regards, Freddie.