Boundary conditions for blood vessel

[fatama]

Hi,

I am modeling a blood vessel, and the pressure and velocity profile are unknown at the outlet. What are the boundary conditions are available in PreView to model that flow at outlet whose values are not known prior to simulation?

Thanks!
Fatama

[ateshian]

Hi Fatama,

If the velocity or pressure are unknown at the outlet, the best you can do is to propose a relation between them that (hopefully) replicates the conditions of your real-world system. Currently FEBio implements a "fluid flow resistance" boundary condition that you can use at the outlet. This boundary condition assumes that the pressure at the outlet scales with the fluid flow rate. You can look up the User's Manual for more details.

Best,

Gerard

[fatama]

Hi Gerard,

Thank you so much for your answer!
I have found from the manual that p=RQ, but confused about how do I set up the value of the resistance (R). Is there any equation to get the value of resistance?

Sincerely,
Fatama

[ateshian]

Hi Fatama,

To figure out R you need to decide what's the pressure you expect in your blood vessel (e.g., 100 mmHg?) and the volumetric flow rate (which is the product of the cross-sectional area of the vessel and the average blood velocity). Basically you need to have some knowledge of these measures in order to run your analysis effectively.

Best,

Gerard