What happen with this square root??
 

Hi everybody!

I want to write a simple operation in my solver:

Tension = zF*sqrt(1-(calcDistance0-0.5)/2.4*(calcDistance0-0.5)/2.4); + forceStatic*(calcDistance0-0.5)/2.4;

Where Tension, zF, calcDistance0 and forceStatic are scalars (static scalar ...)
When I try to compile I find this error:

solveForceBalance.H:154: error: call of overloaded 'sqrt(Foam::scalar)' is ambiguous
/usr/include/bits/mathcalls.h:157: note: candidates are: double sqrt(double)


Help me please!!!

Solved!

scalar aux = Foam:: sqrt(....)

Thank you I didn't think it was a namespace issue. I thought it was a library overload issue.

I have a similar problem. I tried to simplify it to see if sqrt() works at all for me so now I am basically writing sqrt(4) to a vector and that's it. It still doesn't work and I get the following error message:

It is worth mentioning that I am new to coding in OpenFOAM and also to C++ so I am most likely doing something very trivial wrong.
Can someone tell me what I am doing wrong here?

Problem isn't with sqrt, error says problem is with {}.

And also use Foam::sqrt for clarity

Hi,

I got the same error and I'm trying to do my correction. However, it doesn't seem to work.

I need to change the Turbulent frequency equation from :

fvm::ddt(alpha, rho, omega_)
+ fvm::div(alphaRhoPhi, omega_)
- fvm::laplacian(alpha*rho*DomegaEff(F1), omega_)

...

to

fvm::ddt(alpha, rho, omega_)
+ fvm::div(alphaRhoPhi, omega_)
- fvm::laplacian(alpha*sqrt(rho)*DomegaEff(F1), sqrt(rho)*omega_)

I got the error and I changed to:

fvm::ddt(alpha, rho, omega_)
+ fvm::div(alphaRhoPhi, omega_)
- fvm::laplacian(alpha*Foam::sqrt(rho)*DomegaEff(F1), Foam::sqrt(rho)*omega_)

but the error remains. So how should I change it?

Thanks.

Hi, I followed the corrections recommended here too:

https://openfoamwiki.net/index.php/F...9_is_ambiguous

Possible solutions, instead of simply using sqrt(2.0):

::sqrt(2.0)
scalar(::sqrt(2.0))
::sqrt(scalar(2.0))

but it still can't work, although the error msg has changed:

In file included from ../turbulenceModels/lnInclude/kOmegaSSTBase.H:350:0,
from ../turbulenceModels/lnInclude/kOmegaSST.H:111,
from turbulentTransportModels/turbulentTransportModels.C:73:
../turbulenceModels/lnInclude/kOmegaSSTBase.C: In instantiation of ‘void Foam::kOmegaSSTBase<BasicEddyViscosityModel>::corr ect() [with BasicEddyViscosityModel = Foam::LESModels::DESModel<Foam::IncompressibleTurb ulenceModel<Foam::transportModel> >]’:
turbulentTransportModels/turbulentTransportModels.C:130:29: required from here
../turbulenceModels/lnInclude/kOmegaSSTBase.C:469:95: error: no matching function for call to ‘laplacian(Foam::tmp<Foam::GeometricField<dou ble, Foam::fvPatchField, Foam::volMesh> >, Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >)’
- fvm::laplacian(alpha*::sqrt(scalar(rho))*DomegaEff (F1), ::sqrt(scalar(rho))*omega_)
^
../turbulenceModels/lnInclude/kOmegaSSTBase.C:469:95: note: candidates are:
In file included from /home/users/nus/tsltaywb/OpenFOAM/OpenFOAM-v1706_mod/src/finiteVolume/lnInclude/fvmLaplacian.H:188:0,
from /home/users/nus/tsltaywb/OpenFOAM/OpenFOAM-v1706_mod/src/finiteVolume/lnInclude/fvm.H:46,
from ../turbulenceModels/lnInclude/linearViscousStress.C:28,
from ../turbulenceModels/lnInclude/linearViscousStress.H:114,
from ../turbulenceModels/lnInclude/Stokes.H:39,
from ../turbulenceModels/lnInclude/laminarModel.C:27,
from ../turbulenceModels/lnInclude/laminarModel.H:201,
from turbulentTransportModels/turbulentTransportModels.H:31,
from turbulentTransportModels/turbulentTransportModels.C:26:
/home/users/nus/tsltaywb/OpenFOAM/OpenFOAM-v1706_mod/src/finiteVolume/lnInclude/fvmLaplacian.C:45:1: note: template<class Type> Foam::tmp<Foam::fvMatrix<Type> > Foam::fvm::laplacian(const Foam::GeometricField<Type, Foam::fvPatchField, Foam::volMesh>&, const Foam::word&)
laplacian
^
/home/users/nus/tsltaywb/OpenFOAM/OpenFOAM-v1706_mod/src/finiteVolume/lnInclude/fvmLaplacian.C:45:1: note: template argument deduction/substitution failed:
In file included from ../turbulenceModels/lnInclude/kOmegaSSTBase.H:350:0,
from ../turbulenceModels/lnInclude/kOmegaSST.H:111,
from turbulentTransportModels/turbulentTransportModels.C:73:
../turbulenceModels/lnInclude/kOmegaSSTBase.C:469:95: note: ‘Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >’ is not derived from ‘const Foam::GeometricField<Type, Foam::fvPatchField, Foam::volMesh>’
- fvm::laplacian(alpha*::sqrt(scalar(rho))*DomegaEff (F1), ::sqrt(scalar(rho))*omega_)

This above line is the problem, you are changing an unknown variable 'omega_' to 'sqrt(rho)*omega_' and it is dimensionally inconsistent with your other terms.

as you are only multiplying a (non-dim) scalar to the coefficient and not changing the variable, so the above line will work.

This COULD work, test it out, as you are calculating the term explicitly, 'fvc' not 'fvm'

I realised that actually using

::sqrt(rho)
scalar(::sqrt(rho))
::sqrt(scalar(rho))

for the sqrt part can work.

My error is due to representing the Laplacian as:

fvm::laplacian(alpha*::sqrt(rho)*DomegaEff(F1), ::sqrt(rho)*omega_)

The omega and sqrt(rho) are grouped together.

Someone seems to have similar enquires:

https://www.cfd-online.com/Forums/op...ple-terms.html

Anyone has a solution?