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Impedance Boundary condition

Posted: Thu Feb 22, 2024 11:58 pm
by pawanpal
sir


https://simvascular.github.io/documenta ... l#outletbc

i have gone through this link but didn't show how to implement impedance bc type option

how to implement impedance condition please help me

thanks

Re: Impedance Boundary condition

Posted: Tue Feb 27, 2024 4:03 am
by pawanpal
Sir

can you please help me out how to use impedance Boundary condition

Re: Impedance Boundary condition

Posted: Tue Feb 27, 2024 11:52 am
by davep
Hello,

Impedance BCs are no longer supported as an option in the SimVascular GUI, the documentation is out-of-date.

I believe GenBC (https://simvascular.github.io/documentation/genbc.html) can be used to implement impedance BCs.

Cheers,
Dave

Re: Impedance Boundary condition

Posted: Tue Feb 27, 2024 5:47 pm
by wgyang
Impedance BC cannot be prescribed via the SV GUI. It is not used as often as RCR.
To use impedance BC, you need to prepare two files impt.data and Qhistor.dat in order to compute the impedance convolution.
impt.dat has a format similar to rcrt.dat. Each block represent a set of impedance for an outlet.
impt.dat:

nptsImpmax
n1
time_1 value_1
time_2 value_2
...
time_n1 value_n1
n2
time_1 value_1
time_2 value_2
...
time_n2 value_n2
...

where nptsImpmax >= n1, n2 ...
For Qhistor.dat, it stores flow rate data for k impedance outlets.
Qhistor.dat:

n
Q_0_1 Q_0_2 ... Q_0_k
...
Q_n_1 Q_n_2 ...Q_0_k

Then add the following commands to solver.inp

Number of Impedance Surfaces: k # numImpSrfs
List of Impedance Surfaces: id1, id2, id3 ... idk NODEFAULT # nsrflistImp(j), j=0,MAXSURF
Impedance From File: True #False impfile=0, True impfile=1

where k is the number of impedance outlets. id1...to idk are the surface id you assign in the svpre file for impedance outlets.

You can test it with a cylinder model and see if the result makes sense.