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-   -   Time-dependent viscosity implementation in fluent (http://www.cfd-online.com/Forums/fluent/72183-time-dependent-viscosity-implementation-fluent.html)

ComputerGuy January 27, 2010 23:18

Time-dependent viscosity implementation in fluent
 
Does anyone have an example (UDF/literature link?), or know if this is possible to do in fluent? Can one model thixotropy or rheopexy (rheopecty) in this program? I realize it will be a UDF implementation, but I'm unable to see how I would track parcels of fluid to monitor their shear rate vs. time, as thixotropic fluids have age-dependent viscosity.

Could this be implemented by injecting neutrally buoyant, very tiny particles and monitoring their shear vs time, and adjusting the viscosity of the fluid volume which contains them?

Thanks for you help.

Agustin April 19, 2010 10:31

You can use the croos model , if you know the coeficients of the equation, you can create a new component in Define-Materials and viscosity, you select the croos model and you only have to introduce the parameters of the model.
In the tutorial of fluent 2007, the tutorial number 8 talk about the non-Newtonian transitional flow in an eccentric annulus, you can find this in google.
I don't know if you ask about it, but it is the only thing that I know.

Sorry for open an old topic.

moisedion September 20, 2011 03:11

I'm curious to know how you did solve this time dependent rheological Simulation... Was it by UDF or by creating a Solver in OpenFoam? Also, Cross Model is not for Time dependency but Shear Rate Dependency (thinning)...


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