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December 7, 2015, 19:58 |
The mass flux pressure coefficient_FSI model
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#1 |
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Join Date: Mar 2009
Posts: 48
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I am modeling hypertension blood vessel with Reynolds number 700. I used mass flow at inlet and zero pressure at outlet. For FSI modeling the system is stable for E>2 MPa. But according to literature, the Young's Modulus is about 0.5 MPa. In that case the system behaves completely crazy and no convergence. If I used The mass flux pressure coefficient equal to 100, it can converge. Am I allow to use the mass flux pressure coefficient more than 1? any suggestion?
Regards |
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December 22, 2015, 11:22 |
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#2 |
Senior Member
Join Date: Apr 2009
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The mass flux pressure coefficient value is completely case dependent. A value of 100 might be fine for one case, but much too large/small for another. Any positive value could be a valid value. The important thing is to make sure you are converging the quantities of interest. Make sure the case fails with smaller values (1, 10, 50 etc) and you can see the pressure oscillating and diverging. If you use a value that is too large then the solution will be stable but it will never converge so the results will be wrong.
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January 29, 2016, 19:41 |
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#3 |
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Join Date: Mar 2009
Posts: 48
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Hi Stumpy
Thanks for your response. I'm modelling an artery with one inlet and one outlet. When I use the large coefficient of mass flux pressure, the mass flow rate at inlet and outlet are not equal and outlet mass flow is less than inlet. Does that mean it didn't converge? I have to simulate very small Young' modulus <1 in aorta with high blood pressure. I did try higher Young's modulus with lower velocity flow first and slowly increase the flow and decrease the Young's modulus. It did converge with warning in stagger iterations and different mass flow at inlet and outlet (mass flux coefficient= 10). Any Suggestion? Thanks a lot for your help |
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