[Mahyar Javidi]

Hello everyone
I want to add strain rate in interFoam and I do not know how to do that. I need to define one more equation to interFoam similar to the temperature but for volume fraction and I wrote the code for solving the matrix but still have a problem with strain rate.

I defined viscosity like:
surfaceScalarField mu=fvc::interpolate(twoPhaseProperties.mu());

and I tried to define strain rate like:
surfaceScalarField strainRate=fvc::interpolate(viscosityProperties.st rainRate());

which it seems the definition of strain rate is not correct. Do I need to declare sth in creatFields.H for it?
Could anyone help me coding this part.

Regards
Mahyar

[kmooney]

Hi Mahyar,

You could always calculate the strain rate values with something like this in the top level solver:

volScalarField strainRate = sqrt(2.0)*mag(symm(fvc::grad(U)));
surfaceScalarField strainRatef = fvc::interpolate(strainRate);

On another look it seems that the incompressibleTwoPhaseMixture class has a public access function to the viscosityModel class.

Something like this might work as well (warning:untested):

surfaceScalarField strainratef = fvc::interpolate(twoPhaseProperties.nuModel1().strainRate());

I hope that helps!

Cheers,
Kyle

Originally Posted by Mahyar Javidi

Hello everyone
I want to add strain rate in interFoam and I do not know how to do that. I need to define one more equation to interFoam similar to the temperature but for volume fraction and I wrote the code for solving the matrix but still have a problem with strain rate.

I defined viscosity like:
surfaceScalarField mu=fvc::interpolate(twoPhaseProperties.mu());

and I tried to define strain rate like:
surfaceScalarField strainRate=fvc::interpolate(viscosityProperties.st rainRate());

which it seems the definition of strain rate is not correct. Do I need to declare sth in creatFields.H for it?
Could anyone help me coding this part.

Regards
Mahyar

[Mahyar Javidi]

HiKyle

Thanks for your reply. I tried the first part of the code that you mentioned beforein my code and I got an error about the type that strainRate returns (which is double).

I was wondering should I define an object for viscosityModel class and use strainRate function through that object. I think this is the case for twophaseProperties.


Best Regards
Mahyar

[kmooney]

Hi Mahyar,

I'm confused by your statement. How can strainRate return a double if you're initializing the variable to be type volScalarField?

Kyle

[Mahyar Javidi]

Dear Kyle

sorry for the late reply.
This is the exact error that I receive when I used the definition of strainRate in the code.

error: call of overloaded ‘sqrt(double)’ is ambiguous

regards
Mahyar

[kmooney]

try

foam::sqrt

instead

[Mahyar Javidi]

Hi

I used volScalarField strainRate = foam::sqrt(2.0)*mag(symm(fvc::grad(U)));
and I got this: error: ‘foam’ has not been declared

Regards
Mahyar

[kmooney]

you could always just use 1.41421356237!

[Mahyar Javidi]

Thanks Kyle. The solver compiled now.

[wyldckat]

Greetings to all!

This is one of those frequently asked questions... gotta make a note to add this to the FAQ...

Mahyar, please try the following:

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

I don't have time to test any of them right now, but I do vaguely remember that said error message can be overcome with one or more of the above.

Best regards,
Bruno

[Mahyar Javidi]

Hi Bruno

I checked them in my solver and the results are:

scalar(sqrt(2.0)) error: call of overloaded ‘sqrt(double)’ is ambiguous, note: Foam::doubleScalar Foam::sqrt(Foam::doubleScalar)

scalar(::sqrt(2.0)) It works

sqrt(scalar(2.0)) error: call of overloaded ‘sqrt(double)’ is ambiguous

::sqrt(scalar(2.0)) It works

::sqrt(2.0) It works

Regards
Mahyar

[wyldckat]

Hi Mahyar,

Many thanks for testing them all! I've added the working ones to the FAQ: http://openfoamwiki.net/index.php/FA...9_is_ambiguous

Best regards,
Bruno