Convection Term in Linearized Navier Stokes Equations

And901 · October 22, 2014, 11:53

Hi guys,

i'm trying to solve Linearized Navier Stokes Equations.
As we know the convective term is splitted in two parts:

[math] (U\ cdot \nabla) u + (u\ cdot \nabla) U [math]

where U is the base flux.

How can i write the second term in OpenFoam?

RodriguezFatz · October 23, 2014, 03:33

Andrea, this "two parts" splitting only comes up, if you write the equations in a non-conservative way. This is not done in openFOAM, it handles these terms conservatively (thus using tensors):
d/dt(rho U) + nabla dot (rho U U).
You can find how to write these terms for example in "PisoFoam.C":

Code:

 fvm::ddt(U) + fvm::div(phi, U)

October 22, 2014, 11:53	Convection Term in Linearized Navier Stokes Equations	#1
And901 New Member Andrea Join Date: Sep 2014 Posts: 17 Rep Power: 12	Hi guys, i'm trying to solve Linearized Navier Stokes Equations. As we know the convective term is splitted in two parts: [math] (U\ cdot \nabla) u + (u\ cdot \nabla) U [math] where U is the base flux. How can i write the second term in OpenFoam?

October 23, 2014, 03:33		#2
RodriguezFatz Senior Member Philipp Join Date: Jun 2011 Location: Germany Posts: 1,297 Rep Power: 27	Andrea, this "two parts" splitting only comes up, if you write the equations in a non-conservative way. This is not done in openFOAM, it handles these terms conservatively (thus using tensors): d/dt(rho U) + nabla dot (rho U U). You can find how to write these terms for example in "PisoFoam.C": Code: fvm::ddt(U) + fvm::div(phi, U) __________________ The skeleton ran out of shampoo in the shower.

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