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-   -   Doubts on how to represent some terms for viscoelastic Flow Simulation (http://www.cfd-online.com/Forums/openfoam-solving/58002-doubts-how-represent-some-terms-viscoelastic-flow-simulation.html)

titio February 4, 2009 08:42

Hi everybody, I am currentl
 
Hi everybody,

I am currently trying to use OpenFoam to model the flow of incompressible viscoelastic fluids. Currently, I am doubts on how to implement two terms of the differential constitutive that I am using.

In particular, the equation has a term of the form
(1+A*tr(tensor))*tensor, where A is a constant and tensor represent the stress tensorial field. As the operation gives a tensor, I am considering it a source term when solving the equations to determine the extra stress. Can I do it this way?

Also in the calculation of the extra stress term, there is a term in the form div(U*tensor), the divergent of the velocity and the sress tensor. As the fluid is incompressible, I believe i can right the term in the form U*div(tensor), and represent it in OpenFoam language in the form div(phi,tensor), as it is equivalent to a flux term like U*div(U). Can I do this manipulations?

Antonio


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