[paulvrs]

Hello Everyone,

In an attempt to conduct a comparison of different non-newtonian models for studying blood flow, I was wondering if anyone has an idea on how I can acquire the Bird-Carreau-Yasuda model, by changing the constant "a" from the default value of 2, to my preferred one (see https://doc.cfd.direct/openfoam/user...sport-rheology, OF-version7).

According to BirdCarreau.H it is possible to do that ("The Bird-Carreau-Yasuda form is also supported if the optional "a" coefficient is specified. "a" defaults to 2 for the Bird-Carreau model").

However, when I tried to add "a" as (a [ 0 0 0 0 0 0 0 ] 0.5; ) in the BirdCarreauCoeffs sector, the simulation failed, since it expected a word. It actually seems that it doesn't recognize "a" as an option to be set.

Does this mean that a modification of the source-code is required, or am I missing something?

Thank you in advance.
Paul

[fanta]

I succesfully programmed and run almost daily the German Carreau Model, but with ESI OF (v2206). So could you quote your sourcecode and your case so we can have a look? For my Carreaumodel i added a .lib in the run folder and include it in the controlDict.

[paulvrs]

Thanks for the quick reply,

I am attaching the .C and .H files and my transportProperties file which you can add in any case to check whether it works.

[Sheetal Airan]

Hello everyone

I am working on non Newtonian fluids and I need Bingham model or Papanastasiou method for my case but openfoam does not have these model. I make changes in the source file of Bird Carreau model so that it works like Papanastasiou method. I change the viscosity function and the variables. But when I run the case, I got the error given below. I already remove the variable nu0 from the source files wherever it is mentioned. This indicates me that solver is not considering the changes which I made in the Bird Carreau model.

--> FOAM FATAL IO ERROR: (openfoam-2312 patch=240220)
Entry 'nu0' not found in dictionary "/home/sheetal/tutorials/incompressible/BirdCarreauPoiseuille/constant/transportProperties/BirdCarreauCoeffs"

file: constant/transportProperties/BirdCarreauCoeffs at line 27 to 28.

From bool Foam::dimensioned<Type>::readEntry(const Foam::word&, const Foam::dictionary&, Foam::IOobjectOption::readOption, bool, Foam::keyType:ption) [with Type = double]
in file ./src/OpenFOAM/lnInclude/dimensionedType.C at line 104.

FOAM exiting

Any help and suggestions will be appreciated.
Thanks in advance.