Graphically Comparing Results in Paraview Between 2 Different Test Cases

brendancawley · November 17, 2019, 11:54

Hi Guys,

I am having difficulty in figuring out how to graphically compare pressure or velocity field differences between 2 similar cases from Openfoam in Paraview. The cases have slightly different models and I am trying to graphically see where the flow field changes between them rather than comparing with images from slices etc.
Is there any way in Paraview to compare different case results?
Thanks
Bren

tschenkel · November 17, 2019, 12:04

Hello,

Are the different cases on the same mesh? If yes, you can load both cases at the same time and use the pythonCalculator or Calculator filter to calculate the relative difference between the two cases at each cell (or point). You can then visualise that difference.

T

brendancawley · November 17, 2019, 12:14

Hi tschenkel

Thanks for your reply.
Some of the cases are at different velocities but for other cases, where the model has changed, I guess from your reply, that if the mesh changes at all, they can't be compared?
I am familiar with Fluent where two cases could be opened and you could look at a delta pressure or velocity flow field rather than just on an xy graph. Is there any way to achieve something similar?
Thanks again
Bren

November 17, 2019, 11:54	Graphically Comparing Results in Paraview Between 2 Different Test Cases	#1
brendancawley New Member Bren Join Date: Jun 2017 Posts: 2 Rep Power: 0	Hi Guys, I am having difficulty in figuring out how to graphically compare pressure or velocity field differences between 2 similar cases from Openfoam in Paraview. The cases have slightly different models and I am trying to graphically see where the flow field changes between them rather than comparing with images from slices etc. Is there any way in Paraview to compare different case results? Thanks Bren

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November 17, 2019, 12:04		#2
tschenkel Member Torsten Schenkel Join Date: Jan 2014 Posts: 69 Rep Power: 12	Hello, Are the different cases on the same mesh? If yes, you can load both cases at the same time and use the pythonCalculator or Calculator filter to calculate the relative difference between the two cases at each cell (or point). You can then visualise that difference. T

November 17, 2019, 12:14		#3
brendancawley New Member Bren Join Date: Jun 2017 Posts: 2 Rep Power: 0	Hi tschenkel Thanks for your reply. Some of the cases are at different velocities but for other cases, where the model has changed, I guess from your reply, that if the mesh changes at all, they can't be compared? I am familiar with Fluent where two cases could be opened and you could look at a delta pressure or velocity flow field rather than just on an xy graph. Is there any way to achieve something similar? Thanks again Bren