divDevReff?

sharonyue · September 2, 2013, 23:08

Hi guys,

In KEpsilon.C we have:

Code:

tmp<fvVectorMatrix> kEpsilon::divDevReff(volVectorField& U) const
{
    return
    (
      - fvm::laplacian(nuEff(), U)
      - fvc::div(nuEff()*dev(T(fvc::grad(U))))
    );
}

According to my equation, see the image attached.

Should it be:

Code:

return
    (
      - fvm::laplacian(nuEff(), U)
      - fvc::div(nuEff()*T(fvc::grad(U)))
    );

?

GerhardHolzinger · September 5, 2013, 04:06

Take a look at the equations I attached.

sharonyue · September 5, 2013, 09:15

Quote:

Originally Posted by GerhardHolzinger

Take a look at the equations I attached.

Long time no see Gernard, Excellent!!!
Thanks so much

sharonyue · September 8, 2013, 23:30

Woo, but if these two terms are the same? Why should we use the dev instead of neglecting it?

GerhardHolzinger · September 9, 2013, 02:28

It two terms are equal you are neglecting nothing.

There may be numerical or other reasons for doing so.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Calculating divDevReff	jposunz	OpenFOAM Running, Solving & CFD	82	June 12, 2022 14:01
Usinng divDevReff vs div(R) + laplacian(nu,U)	mchurchf	OpenFOAM	5	April 8, 2015 08:29
turbulent energy in UEqn / divDevReff	Andreas.Herwig	OpenFOAM Running, Solving & CFD	0	April 12, 2011 10:50
About devReff() and divDevReff() in kEpsilon.C	Zheng.Zhi	OpenFOAM	0	August 24, 2009 02:05

September 8, 2013, 23:30		#4
sharonyue Senior Member Dongyue Li Join Date: Jun 2012 Location: Beijing, China Posts: 838 Rep Power: 17	Woo, but if these two terms are the same? Why should we use the dev instead of neglecting it?

September 9, 2013, 02:28		#5
GerhardHolzinger Senior Member Gerhard Holzinger Join Date: Feb 2012 Location: Austria Posts: 339 Rep Power: 28	It two terms are equal you are neglecting nothing. There may be numerical or other reasons for doing so.