about steady flow in the tutorial "coronary normal"

Provides a system for patient-specific cardiovascular modeling and simulation.
POST REPLY
User avatar
Wei Wu
Posts: 16
Joined: Thu Jul 01, 2021 9:09 am

about steady flow in the tutorial "coronary normal"

Post by Wei Wu » Wed May 11, 2022 2:33 pm

Hi every guy,

I tried the steady flow files in the tutorial coronary normal. However, its parameter setting really confuses me:

1, all the outlets are set as "Resistance."
my question: could "RCR" and "Coronary" be set for the outlets in steady flow simulation?

2, the calculation of the "Resistance" parameters is a maze. I tried many ways, but I can't get these parameters.
my question: could anyone explain how these parameters are calculated for steady flow simulation?

Furthermore, I wonder how I can decide whether the steady flow simulation gets convergence?

Thanks in advance!

User avatar
David Parker
Posts: 1764
Joined: Tue Aug 23, 2005 2:43 pm

Re: about steady flow in the tutorial "coronary normal"

Post by David Parker » Fri May 13, 2022 11:18 am

Hi Wei,

1, all the outlets are set as "Resistance."
my question: could "RCR" and "Coronary" be set for the outlets in steady flow simulation?


Boundary conditions are needed for both steady and unsteady flow.

2, the calculation of the "Resistance" parameters is a maze. I tried many ways, but I can't get these parameters.
my question: could anyone explain how these parameters are calculated for steady flow simulation?


The resistance parameters are determined using the cardiac output and the geometry of the coronary vessels. There is no difference in the parameters for a steady flow simulation.

Have a look at the papers referenced in the SV documentation. http://simvascular.github.io/clinicalCase3.html

Furthermore, I wonder how I can decide whether the steady flow simulation gets convergence?

A simulation converges when the results don't change.

Cheers,
Dave

User avatar
Wei Wu
Posts: 16
Joined: Thu Jul 01, 2021 9:09 am

Re: about steady flow in the tutorial "coronary normal"

Post by Wei Wu » Mon May 16, 2022 6:59 am

Hi David,

Thank you so much for your kind reply!
I double checked the parameters, however, I still get confused.
As for pulsatile flow, the whole R of aorta cap should be 139.97/0.09 = 1555; while the steady flow has the setting of 1492. And for the steay flow the R ratio between the aorta and whole coranary vessels is far from 1:24.
Could you please have a check?
Thank you again!!

User avatar
David Parker
Posts: 1764
Joined: Tue Aug 23, 2005 2:43 pm

Re: about steady flow in the tutorial "coronary normal"

Post by David Parker » Wed May 18, 2022 7:53 pm

Hi Wei,

It's not clear from the documentation what values were used to set the simulation parameters. You will need to read the paper referenced there to see how they were determined.

The SV documentation does state that the aorta outflow resistance is computed using Rd = 0.91 * Rtot where Rtot = Pmean / Q, where Q = 90.7.

Cheers,
Dave

POST REPLY