[sinah]

Hi everyone
I am trying to simulate the free surface of a viscoelastic fluid I intend to use oldroyd-B model and VOF for free surface calculation. I appreciate any help

[billy]

Hi

I am also interested in this topic and I am willing to work on this.

[sradl]

Hello,

any progress in this subject? I've done some simulations using Oldroyd-B models, FENE-type models, etc. with a self-developed code. I just want to warn you: simulation of viscoelastic fluids is NOT straight forward and additional numerical problems arise, i.e. you have to stabilize the simulation otherwise you will get a blow up (high-weissenberg number problem).

So if you have any clue, how to include in OpenFOAM, I could assist with some expertise in (complicated) stabilizing simulations (actually, there are a lot of techniques, we have used simply a dissipation term to smooth the stress field).


Cheers
Stefan

[sinah]

hi stefan
For my project I've done some experimental works with CMC solution this solution can adequately be modeled with power-law like equations although it shows viscoelastic effects, anyway I have added some of these models to openfoam and gained some coding experience(It was some coding practice not viscoelastic simulation;)). But I am still very interested in that topic and if you like we can cooprate.
good luck
sina

[rvajapey]

Hello OpenFOAM experts

I have been trying to implement the Maxwell and Oldroyd-B models to study the viscoelastic flow phenomenon. I have stability problems as told by Mr. Stefan Radl. I would like to know more about these problems. Any help would be appreciated.

thank you veru much

Raghu

[sradl]

Dear Raghu,

I can send you my work if you like, or you can look into my aiche paper [Radl, Tryggvason, Khinast. Flow and mass transfer of fully resolved bubbles in non-Newtonian fluids. AIChE 53 (2007), 1861-1878].

Usually, these fluids behave like beasts - I'd start with a simple (unsteady) shear flow to show the solver is working.

br
Stefan Radl

[caw]

Dear Stefan,

i would be interessted in your work as well :-)
Regarding these fluids as beasts is probably the appropriate description..

Best regards
Christian

[kerstin]

Hi,

The stability problems come from the fact, that these "damn stresses" don't have a diffusion term in the PDE. Diffusion makes life so much easier ;-)

This paper gives an overview about higher order methods for FVM method and viscoelastic models...maybe of some help?

J. Non-Newtonian Fluid Mech. 93 (2000) 287–314
Effect of a high-resolution differencing scheme on
finite-volume predictions of viscoelastic flows
M.A. Alves , F.T. Pinho, P.J. Oliveira

Kerstin

[ibrahim]

Hi,

The source stability problem is extended inf-sup (LBB) conditions. Introducing extra stress terms to governing equations includes extra compatibility conditions. Accuracy of velocity gradients has significant impact on stability/accuracy of schemes. We addressed these issues in our article "Computation of incompressible and weakly-compressible viscoelastic liquids flow: finite element/volume schemes
Journal of Non-Newtonian Fluid Mechanics
Volume 126, Issues 2-3, 10 March 2005, Pages 123-143 ".

[commonyue]

Hi dear sradl, i am working on the viscoelastic fluid, and need to write the code by myself, however, i have not got any clue by now, i wonder could you please send me your work on this kind of complex fluid. thanks so much, i am really appreciate your kind help. Best Regards.Li

Originally Posted by sradl

Dear Raghu,

I can send you my work if you like, or you can look into my aiche paper [Radl, Tryggvason, Khinast. Flow and mass transfer of fully resolved bubbles in non-Newtonian fluids. AIChE 53 (2007), 1861-1878].

Usually, these fluids behave like beasts - I'd start with a simple (unsteady) shear flow to show the solver is working.

br
Stefan Radl

[santiagomarquezd]

Hi, this thread might be useful:

http://www.cfd-online.com/Forums/ope...interfoam.html

Regards.

[bfzah]

Hello
How can I form a vortex in a square-shaped channel?
Or how can I see vortices?
In all the papers, a vortex pair is seen at the corners of the channel with the Giesekus model.
How can this be modeled with open foam?
what is the properties flow ?
B.C ?

please help me?

my Email: farhadhoseinbor@gmail.com
Telegram id: @bfzah