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kiriký July 14, 2009 11:38

How to add a time dependent source term to icoFoam?
Hi All,
I'm a new OF-1.5 user on a ubuntu 8.04 64 bit machine and I'm trying to run a DNS simulation on a channelOodles-like mesh, with air incompressible flow, moved only by an imposed constant pressure gradient. The boundary conditions are the same of channelOodles tutorial, but I used icoFoam solver to which I''ve added the constant pressure gradient term, for running a direct numerical simulation without pre-imposed numerical models.

I've correctly setted the case, adding a new constant vector to trasportProperties file:

nu nu [0 2 -1 0 0 0 0] 1.8e-5;
DT DT [0 2 -1 0 0 0 0] 0.002;
myVector myVector [0 1 -2 0 0 0 0] (-8e-4 0 0);

then, adding a reference to it in createFields.H file:

dimensionedVector myVector

and, finally, adding the new constant tensor in the icoFoam.C file:

fvVectorMatrix UEqn
+ fvm::div(phi, U)
- fvm::laplacian(nu, U)
+ myVector

The simulation works correctly and I obtain the prescribed theoric laminar velocity profile.
Now I must run the same simulation introducing a time dependent variable pressure gradient term - myVector(t) - which would have to develop a turbulent flow regime. The fact that I continue to use icoFoam is dued to the necessity to demonstrate the expected flow regime without prior knowing the flow behaviour.

I'm not able to properly configure the solver and the other necessary files for introducing myVector(t) term.

Can someone help me?

Thanks to All,


entitledx July 16, 2009 09:06

Just bumping this up. I'm also really interested in knowing how to add a time dependent source term in openFoam.

wchen March 23, 2014 21:24

Hi guys,

I know it's been almost 5 years but I just started a project trying to add a time dependent pressure gradient in the UEqn in icofoam. Did any of you figure out how to do it?


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