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FlowHist.dat file and PressHis.dat

Posted: Tue Mar 05, 2024 11:18 am
by seoye
Hello, I'm new to Simvascular and currently running a simulation using svSolver.

Whenever I run 3d simulation using svsolver, I get FlowHist.dat file and PressHis.dat file as an output file.
However, the problem here is that I only get the value of flow rate and pressure of outlets from FlowHist.dat and PressHist.dat, respectively.

As I want to calculate flow rate and pressure from both inlets and outlets, I believe I need to add some line from input.config to my .inp file but cannot figure out which one is the right one.

Please help me out with the problem. Thank you in advance.

Re: FlowHist.dat file and PressHis.dat

Posted: Wed Mar 06, 2024 2:52 pm
by davep
Hello,

Average flow and pressure values for all inlets and outlets are computed using the SimVascular Simulation Tool Convert Results panel. These values can't be computed using the command line.

I am seeing NaN's in your files, that is not good!

Cheers,
Dave

Re: FlowHist.dat file and PressHis.dat

Posted: Tue Mar 19, 2024 8:32 am
by seoye
Thank you so much for your help.

May I ask you one more question?
You mentioned that NAN's in PressHist.dat file indicates bad sign of the simulation results.
What does NaN represents and when does it appears?

Thank you so much for your help in advance.

Re: FlowHist.dat file and PressHis.dat

Posted: Tue Mar 19, 2024 1:09 pm
by davep
Hello,

NaNs represent a special numeric value that is Not a Number. This typically occurs when an infinite value is computed (e.g. divide by 0).

NaNs can occur in a simulation when doing the nonlinear/linear solve for a ill-conditioned system of equations resulting from incorrect BCs or too large a time step.

Cheers,
Dave