[eldudereeno]

Hi Gijsbert,

thank you !
Its working (but with k -> 0 2 -1 0 0 0 0)

I am using the nonNewtonianIcoFoam solver.
Its running but not very stable.

[T.D.]

Hi Foamers,
i built already my own viscosityModel and all is ok
But i face a huge problem now

what to do? i need to use two different transportModels in the same solver.

How this can be done and compiled?
how to call back the two different viscosities from their models inside the solver, let's say icoFoam?


thanks a lot

[sharonyue]

Hi,

Does anyonw know what does k and tau0 mean?
{
transportModel HerschelBulkley;
rho rho [ 1 -3 0 0 0 0 0 ] 900;
HerschelBulkleyCoeffs
{
nu0 nu0 [ 0 2 -1 0 0 0 0 ] 11;
tau0 tau0 [ 0 2 -2 0 0 0 0 ] 0.01;//m2/s2
k k [ 0 2 -1 0 0 0 0 ] 0.2;
n n [ 0 0 0 0 0 0 0 ] 0.12;
}

tau0 is tau/density?
but k's deminsion is the same with nu,which should be pas^n?

[vonboett]

Originally Posted by sharonyue

Hi,

Does anyonw know what does k and tau0 mean?
{
transportModel HerschelBulkley;
rho rho [ 1 -3 0 0 0 0 0 ] 900;
HerschelBulkleyCoeffs
{
nu0 nu0 [ 0 2 -1 0 0 0 0 ] 11;
tau0 tau0 [ 0 2 -2 0 0 0 0 ] 0.01;//m2/s2
k k [ 0 2 -1 0 0 0 0 ] 0.2;
n n [ 0 0 0 0 0 0 0 ] 0.12;
}

tau0 is tau/density?
but k's deminsion is the same with nu,which should be pas^n?

Yes, its all about the difference between kinematic and dynamic viscosity. k represents your "tangential" viscosity, for example if you reduce to the Bingham Model (n=1) k is the incline of the Bingham line.

But there is a nice principal problem: When your fluid accelerates and the shear rate rises, you get a high dependency to timestep size, because the error from overestimation of viscosity over the timestep length sums up! Simulating flume experiments with release boxes using interFoam can demonstrate this.