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-   -   Simulation of Blood Flow (https://www.cfd-online.com/Forums/star-ccm/135905-simulation-blood-flow.html)

fardinkhalili May 21, 2014 10:25

Artery and Tissue
 
Sathwik,

Use only one fluid physics for both regions. Select Eulerian multiphase and choose two phases with different properties. And artery is porous region and tissue is fluid region.
In Star-CCM the Darcy-Forchheimer equation is used by default. The inertial resistance coefficient is the Forchheimer term. To use the regular Darcy's law, simply set this coefficient to be zero.
Use the interface as baffle

fardinkhalili May 21, 2014 10:28

No vof
 
Sathwik,

And totally forget about VOF. Change fluid physics models.

me3840 May 21, 2014 10:44

fardinkhalili,

I don't see how using EMP will allow them to move one phase across the interface but not the other.

fardinkhalili May 21, 2014 10:48

Artery and tissue
 
So you mean he can use two fluid physics, one for artery and one for tissue, then use porous region for artery that cause blood go through the baffle interface and get into the tissue. Right?

me3840 May 21, 2014 10:57

Not quite. But this could be done a couple ways I suppose.

The way he's trying to do it, he has the tissue as a porous media which is also some fluid (some kind of plasma or something?). The blood needs to be able to move through the artery and into the tissue, but not the fluid in the tissue into the artery. Once in the tissue, the blood would mix with the second fluid.

Now you could just say everything is blood and just treat the tissue as a porous media, then you would only need a single phase and this is really easy. But I think from what he's saying for some reason he needs the first option.

Is that true Sathwik?

narmada May 21, 2014 12:18

The only fluid in both the regions is blood.so do u want me to set only one phase that too for artery??

me3840 May 21, 2014 12:27

If there was only one phase to begin with, I'm not sure why you were trying to mess with multiphase models; perhaps some of the fault is on me for not questioning that. But yes, just use a single liquid and make your porous medium the second region, and this is very easy.

narmada May 21, 2014 12:30

I want the artery to be permeable not porous.

me3840 May 21, 2014 13:18

What's the difference?

narmada May 21, 2014 14:13

Porosity:space in between the moleculesPermeability: ease of flow in that area

me3840 May 21, 2014 14:18

In STAR-CCM+, there's a value on porous media called porosity which is analagous to how much area of a plate with holes is open, and then there are the porous coefficients, which modify how easy it is for flow to move. I would think you'd want to leave the porous coefficients to zero and just modify porosity then.


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