Variable Wall Tube Simulation Problem

Brennen Carr · Post by **Brennen Carr** » Fri Jun 30, 2017 12:27 pm

Hey SimVascular team,

I have been following along with the simulation tutorial that you guys provide but have been unable to get the tube with variable walls to satisfy continuity. After the simulation completes I open the converted results in ParaView and then extract the inlet and outlet to calculate the surface flow for each.

I defined my inlet to have a steady flow of -10 cc/sec but at the outlet the flow will vary from -26 to -220 cc/sec over the course of my simulation (1 period, 1000 time steps, 0.001 second length). other than the inlet flow, I used all of the values supplied in the tutorial. Do you guys have any suggestions on what might be the issue or do you need any additional information?

Thanks,
Brennen

Hongzhi Lan · Post by **Hongzhi Lan** » Fri Jun 30, 2017 6:09 pm

Hi Brennen,

I'm not sure what caused it. Could you send the whole project to me? I'll take a look.

Thanks,
SimVascular Development Team

Brennen Carr · Post by **Brennen Carr** » Thu Jul 06, 2017 9:03 am

How would you like me to send you the file? it is to large to upload as an attachment on the forum.

Hongzhi Lan · Post by **Hongzhi Lan** » Thu Jul 06, 2017 9:57 am

You can put into a dropbox and share the link with me (hongzhi@stanford.edu)

SimVascular Development Team

Hongzhi Lan · Post by **Hongzhi Lan** » Fri Jul 07, 2017 1:41 pm

I checked your files. I think you didn't save the project after simulations, so i couldn't see the parameter values you used.

But one reason I think is, for steady_rcr_variable, you didn't use the simulation result from steady_rcr as initial condition

check this example as below about how set up initial conditions(IC) based on previous simulation results
http://simvascular.github.io/docsFlowSo ... l#example3

SimVascular Development Team

Brennen Carr · Post by **Brennen Carr** » Mon Jul 10, 2017 9:22 am

I must have uploaded the wrong files, because I am confident that I had done that on my simulations.

Regardless, I reran and saved stead_rcr and steady_rcr_variable. however, I am still getting inlet and outlet flows that are unreasonably different. I have uploaded these files to the drive if you would not mind taking a look at them.

Thanks,
Brennen

Hongzhi Lan · Post by **Hongzhi Lan** » Mon Jul 10, 2017 11:50 am

I found out the initial displacement is so large at displacement.vtp. I'm asking someone else in our lab to take a look at the issue.
What OS and what version of SimVascular are you using?

SimVascular Development Team

Brennen Carr · Post by **Brennen Carr** » Mon Jul 10, 2017 12:54 pm

I am running Simvascular 3.0 on Ubuntu 14.04

Hongzhi Lan · Post by **Hongzhi Lan** » Mon Jul 10, 2017 4:27 pm

Since your initial displacement was so large, we think the pressure your used in "Wall Properties" was 1333300 which is way beyond the physiological range. You need to use some value close to 13333.

For simulation with deformable walls, you can try to use "GMRES" for svLS Type in "Solver Parameters"

SimVascular Development Team

Hongzhi Lan · Post by **Hongzhi Lan** » Mon Jul 10, 2017 4:53 pm

Sorry, you should use 133300.

Variable Wall Tube Simulation Problem

Variable Wall Tube Simulation Problem

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