[moraza]

Hi foamers,
I am currently trying to post process an open channel flow with paraview. I am trying for the last one moth and search forums to get an answer for my problem.
I want to draw contours for flow depths like the attached picture.

[flotus1]

At which point in the process are you stuck? I can give you some hints, but since I haven't done the exact same plot you will still have to do some fumbling around on your own.

First of all, I assume this is some kind of 3D multiphase simulation like VOF?
Then you should be able to create an iso-surface of fluid phase=0.5 to represent the interface. Then on this interface, you can create a contour plot of the height coordinate. In case the floor is not 0, create a calculator first which subtracts the floor height.
There will still be some more cosmetics to get the plot looking like your example, but I hope this helps get you started.

Then again, why do a 2D contour plot when you could just as well show the 3D isosurface of the fluid phase?

[moraza]

Thank you for the quick reply.
Yes, this is a 3D multiphase flow (VOF method).

Attached are few pictures of what I have done so far.

Then I imported the .csv file to ArcMap to create a contour, but the contour was a bit messy.

One last question. In my case there is a bed slope of 10^-6, how can I calculate the depths at different points using calculator?

As for as 2D contours is concerned, I want to do this for validation

[flotus1]

Looks like you are almost there, just a bit more cosmetics.
As for the slope...I guess you could derive a formula for the floor z-coordinate at every given xy-coordinate. Then subtract that in the calculator from the z-coordinate of the iso-surface.

Messy contours: Paraview has a built-in "smooth" filter. You might try that on the iso-surface, but it could be considered cheating, depending on who you ask.

[moraza]

Thank You for the encouragement,

I am facing another problem. In my case the geometry is symmetrical, but for some reasons on the downstream side of the cylinder the results seems to be unsymmetrical. My question is, Is there any problem with the geometry or mesh.
Pic attached

[flotus1]

There could be a lot going on... this question would be better suited in the sub-forum of the solver you are using. You will have to give more details about the flow, your solver and its settings. And the mesh you used. Be descriptive, show pictures.
If you used none of the solvers that have a dedicated sub-forum here, try the main forum.

First things that come to mind, in no particular order:

• flow field is stationary, but your simulation is not fully converged
• flow field is unsteady, you used a transient solver, and this just happens to be the result at which you stopped the simulation
• flow field is unsteady, you used a steady-state solver, and it did not suppress all low-frequency oscillations