definition norm of strain rate

matthias · September 17, 2010, 10:47

Hi,

the norm of the strain rate tensor is defined as mag(S) = sqrt( 2 * S_ij S_ij ) where S_ij = 1/2 ((grad(U)+grad(U)^T) = symm(grad(U)). OF defines mag(S) = sqrt(S_ij S_ij) , both expressions differ in the factor of sqrt(2).
However, it could be important for the determination of tau_ij in the turbulence models(i.e. Smagorinsky)!

Is it a possible bug?

best regards

Matthias

mattijs · September 17, 2010, 11:07

We've finally got a proper bug reporting system :-)
Please report any OpenFOAM bugs on http://www.openfoam.com/bugs.

Thanks,

Mattijs

September 17, 2010, 10:47	definition norm of strain rate	#1
matthias Member Matthias Walter Join Date: Mar 2009 Location: Rostock, Germany Posts: 63 Rep Power: 17	Hi, the norm of the strain rate tensor is defined as mag(S) = sqrt( 2 * S_ij S_ij ) where S_ij = 1/2 ((grad(U)+grad(U)^T) = symm(grad(U)). OF defines mag(S) = sqrt(S_ij S_ij) , both expressions differ in the factor of sqrt(2). However, it could be important for the determination of tau_ij in the turbulence models(i.e. Smagorinsky)! Is it a possible bug? best regards Matthias

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September 17, 2010, 11:07		#2
mattijs Senior Member Mattijs Janssens Join Date: Mar 2009 Posts: 1,419 Rep Power: 26	We've finally got a proper bug reporting system :-) Please report any OpenFOAM bugs on http://www.openfoam.com/bugs. Thanks, Mattijs