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Best way to prescribe a transient flow waveform

Posted: Thu Sep 20, 2018 2:24 pm
by gupta_akash
Hello All,

I have a flow waveform that I've generated from an LPN model that I'd like to prescribe to a face as a boundary condition. The total time period is 4.094s with 1 millisecond time steps, so I have a flow file ready with 4094 time and flow values. I know that I need 50 Fourier modes to adequately capture the pulsatility. What values would you guys recommend that I set for point number and period while generating the boundary condition DAT/VTP files?

Thanks!

Re: Best way to prescribe a transient flow waveform

Posted: Fri Sep 21, 2018 11:56 am
by shakedregev
If you're specifying the entire file (meaning it is not periodic), you should pad the file on the end with the value you had at the last time step (otherwise it tries to interpolate to the beginning). 1 second should be plenty. Don't touch the period, let that generate automatically from the file, and set the point number to # of time steps.

Re: Best way to prescribe a transient flow waveform

Posted: Wed Oct 10, 2018 7:17 am
by gupta_akash
Good advice. I don't really use the GUI so I have to explicitly specify the numbers. If say I wanted to repeat the flow waveform prescribed in the .flow file, should the period be set to 2? I vaguely remember that there's a way to tell SimVascular to replicate the flow waveform, say 3 times(3 periods basically) and SimVascular would create a BC file with the input flow waveform repeated thrice, joined end to end.

Re: Best way to prescribe a transient flow waveform

Posted: Mon Oct 22, 2018 1:57 pm
by shakedregev
You would need to make the period a third of your simulation time to repeat it 3 times within the simulation.