Hi,

Daniel, it's awesome that you got results with DES and DDES for
channelOodles. What does it look like? Is the RANS region increased in
DDES? For IDDES, I personally have no interest in it since it's for
WMLES. But I would be glad to see if it helps with log layer mismatch.

For the boundary conditions, I have had a few concerns about them, and
I'm not quite sure that I impose nuTilda and nuSgs correctly. I ran
cases using, at the inlet, a Dirichlet condition for nuTilda and a
Neumann condition for nuSgs and it worked fine:

FoamFile
{
version 2.0;
format ascii;

root "";
case "";
instance "";
local "";

class volScalarField;
object nuTilda;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* * * //

dimensions [0 2 -1 0 0 0 0];

internalField uniform 0.0000693426;

boundaryField
{
inlet
{
type fixedValue;
value uniform 0.0000693426; // nu_t/nu = 1
}

outlet
{
type inletOutlet;
inletValue uniform 0;
value uniform 0;
}

wall
{
type fixedValue;
value uniform 0;
}
}

FoamFile
{
version 2.0;
format ascii;

root "";
case "";
instance "";
local "";

class volScalarField;
object nuSgs;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* * * //

dimensions [0 2 -1 0 0 0 0];

internalField uniform 1.5e-5;

boundaryField
{
inlet
{
type zeroGradient;
}

outlet
{
type zeroGradient;
}

wall
{
type zeroGradient;
}
}

Best regards,

Philippe

nuTilda and nut
 

hi Hrv,
I am struggling since one week to understand why nuTilda have to be set in some case where the SpalartAllmaras modell is not used.
After a deep look in the src of all turbulence models ,I have founded ,that nuTilda is only defined in SpalartAllmaras model
SpalartAllmaras: nuTilda = nut/nu;
KEpsilon: nut = Cmu*k^2 /epsilon;

why do I have to set nuTilda when for example the KEpsilon model is used. why all turbulence model have to solve the nuTilda equation?


kind regards


gerard

I guess Hrv could not answer your question.At least I could not reproduce this problem.I do not need to solve nuTilda when using kepsilon model.

different dimentions
 

Hi
can you explane me the meaning of this error?


LHS and RHS of + have different dimensions
dimensions : [0 2 -2 0 0 0 0] + [1 -1 -2 0 0 0 0]

I got it in launching interDyMFoam in OF 1.5-dev,
It is a bug? how to fix it? I read I have (maybe) to recompile the solver, can you help me?


Thanks
Aldo

That one I know! ;)

the error clearly statest, your LHS and RHS have different dimensions, namely:
LHS has dimension of: m^2/s^2
and RHS has dimenstions of: kg/m/s^2. You don't need to recompile anything, only to check the dimensions of variables in your 0 directory. Once you set this properly, everything will run fine. There's also possibility to turn-off the dimension check, but it's not a good idea at all.

good luck
matej

Hi at all

I have a similar problem. I want to solve a simpleFoam case with SpalartAllmaras. Can someone help me with this error?!

incompatible dimensions for operation
[U[0 1 -2 0 0 0 0] ] == [-grad(p)[1 -2 -2 0 0 0 0] ]

If I set up the case with an comressible solver (rhoPisoFoam) the error is similar.

thx