problem with FSI artery mechanical result

raminostadi · February 22, 2017, 08:55

Hello experts.
I'm working on FSI simulation in an bifurcating artery by coupling fluent and
transient structural. I Know here is cfx forum but maybe someone had exprience about this.
my boundry conditions are pulse velocty inlet ( depends on time and writing as a transient profile) and zero pressure in outlets.
simulation run successfully but result of mechanical is incorrect. when I see stress result at different time,the artery miss geometrical form and when I
animate stress,no change occure during the animation.
mesh and skewness chart.jpg

stress at last time.jpg

stress at maximum inlet velocity.jpg

artery during animation.JPG

can anyone help me?
thanks for your attention.

yk2359 · September 11, 2017, 11:02

Quote:

Originally Posted by raminostadi

Hello experts.
I'm working on FSI simulation in an bifurcating artery by coupling fluent and
transient structural. I Know here is cfx forum but maybe someone had exprience about this.
my boundry conditions are pulse velocty inlet ( depends on time and writing as a transient profile) and zero pressure in outlets.
simulation run successfully but result of mechanical is incorrect. when I see stress result at different time,the artery miss geometrical form and when I
animate stress,no change occure during the animation.
Attachment 54164

Attachment 54165

Attachment 54166

Attachment 54167

can anyone help me?
thanks for your attention.

Hello!

Did you manage to find any solution to this? I am working on a bit similar model.

Lance · September 12, 2017, 03:43

Check the stress values. The previous post had stress values on the order or 0.001 MPa, which might be too low to get deformation (?). How much stress to you anticipate? Also, zero pressure BCs might not be suitable here, instead use something more physiological? Blood pressure?

yk2359 · September 12, 2017, 10:13

Quote:

Originally Posted by Lance

Check the stress values. The previous post had stress values on the order or 0.001 MPa, which might be too low to get deformation (?). How much stress to you anticipate? Also, zero pressure BCs might not be suitable here, instead use something more physiological? Blood pressure?

Hello Lance,

Thank you for the response. I am new to 2 way FSI. I have similar artery model. Calculated stress values are low. I considered a basic sine wave for inlet velocity and zero/atm pressure at both inlet & outlet. If available, can you please share any realistic UDF for pressure conditions at both ends?

Also, is deformed the shape of artery shown in 3rd attachment of the previous post the true behavior of artery post simulation? Or is it just the scaled deformed model?

Thanks.

Lance · September 12, 2017, 10:41

I am sure there are pressure values available in the literature - dont trust strangers on the internet

I really hope my arteries dont look like that image, it is probably just a poor representation of a scaled up deformation.

February 22, 2017, 08:55	problem with FSI artery mechanical result	#1
raminostadi Member ramin Join Date: Jul 2016 Posts: 41 Rep Power: 10	Hello experts. I'm working on FSI simulation in an bifurcating artery by coupling fluent and transient structural. I Know here is cfx forum but maybe someone had exprience about this. my boundry conditions are pulse velocty inlet ( depends on time and writing as a transient profile) and zero pressure in outlets. simulation run successfully but result of mechanical is incorrect. when I see stress result at different time,the artery miss geometrical form and when I animate stress,no change occure during the animation. mesh and skewness chart.jpg stress at last time.jpg stress at maximum inlet velocity.jpg artery during animation.JPG can anyone help me? thanks for your attention.

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September 12, 2017, 03:43		#3
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	Check the stress values. The previous post had stress values on the order or 0.001 MPa, which might be too low to get deformation (?). How much stress to you anticipate? Also, zero pressure BCs might not be suitable here, instead use something more physiological? Blood pressure?

September 12, 2017, 10:41		#5
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	I am sure there are pressure values available in the literature - dont trust strangers on the internet I really hope my arteries dont look like that image, it is probably just a poor representation of a scaled up deformation.