Momentum equation of Darcy's law

sambatra · April 17, 2009, 03:25

Hi there,
I'm dealing with combustion modeling which takes into account Darcy's law for the momentum equation.I'm trying to solve thi momentum equation and it seems like I got trouble:
the velocity equation is:
U = -K*fvc:grad(p); where K is constant to be calculated
the pressure equation is:
div(-K1*grad(p2)) = source term
to implement this into the code I tried this following syntax:
-fvm:laplacian(-K1,pow(p,2)) == S where S is the source term to be calculated also
and I came out with an error message like GeometricField:double....or something
Can somebody out there help me out and tell me what I have to do to implement this pressure equation into the code?
I have already posted this but nobody answered yet
Please,
Regards,

olesen · April 17, 2009, 03:49

You might wish to examine the rhoPorousSimpleFoam solver to gather some ideas.

sambatra · April 17, 2009, 04:27

I have just taken a look at the rhoPorousSimpleFoam solver,
but you know, I am new to Openfoam and there are some syntax in the code I dont know and I cant find in the programmers guide such as 'tmp<>', so I'm struggling a bit.
My question is:
is it possible to have this fvm:laplacian(k,pow(p,2)) in the lapalcian scheme?
or do I have to cast 'p' in the coefficient 'k' and I get this
fvm:laplacian(k1,p)?
Regards,

April 17, 2009, 03:25	Momentum equation of Darcy's law	#1
sambatra New Member andrianomena Join Date: Mar 2009 Location: madagascar Posts: 23 Rep Power: 17	Hi there, I'm dealing with combustion modeling which takes into account Darcy's law for the momentum equation.I'm trying to solve thi momentum equation and it seems like I got trouble: the velocity equation is: U = -Kfvc:grad(p); where K is constant to be calculated the pressure equation is: div(-K1grad(p2)) = source term to implement this into the code I tried this following syntax: -fvm:laplacian(-K1,pow(p,2)) == S where S is the source term to be calculated also and I came out with an error message like GeometricField:double....or something Can somebody out there help me out and tell me what I have to do to implement this pressure equation into the code? I have already posted this but nobody answered yet Please, Regards,

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April 17, 2009, 03:49		#2
olesen Senior Member Mark Olesen Join Date: Mar 2009 Location: https://olesenm.github.io/ Posts: 1,715 Rep Power: 40	You might wish to examine the rhoPorousSimpleFoam solver to gather some ideas.

April 17, 2009, 04:27		#3
sambatra New Member andrianomena Join Date: Mar 2009 Location: madagascar Posts: 23 Rep Power: 17	I have just taken a look at the rhoPorousSimpleFoam solver, but you know, I am new to Openfoam and there are some syntax in the code I dont know and I cant find in the programmers guide such as 'tmp<>', so I'm struggling a bit. My question is: is it possible to have this fvm:laplacian(k,pow(p,2)) in the lapalcian scheme? or do I have to cast 'p' in the coefficient 'k' and I get this fvm:laplacian(k1,p)? Regards,