CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   linearization of k-e source terms (http://www.cfd-online.com/Forums/main/11483-linearization-k-e-source-terms.html)

khaiching May 19, 2006 05:44

linearization of k-e source terms
 
Hi: APpreciate if anyone could enlighten me on this:?

(1) What are the standard techniques designed to linearize the source terms for the k-e equations? Could anyone please advise on the available references?

(2) If I would like to include the buoyant terms into the k-e source term, what would be the correct implementation? Any idea on how to make the buoyant term more "implicit", i.e. transfer that to the main diagonal of the coefficient matrix?

TQ

-khai ching-

ganesh May 19, 2006 14:50

Re: linearization of k-e source terms
 
Dear khaiching,

There is a paper by Prof. Dick's group on linearisation of source terms for k-epsilon and k-w equations. I can mail it to you if you give your mail id

Regards,

Ganesh


khaiching May 20, 2006 00:08

Re: linearization of k-e source terms
 
Hi Ganesh, my email id is: ngkhaiching2000@yahoo.com. Thanks for your help..:)

mabinty July 10, 2009 06:17

Hi Ganesh!!

I would kindly ask you to send me the paper on linearisation of source terms of k-epsilon equations by Erik Dick s group:

aram.amouzandeh@tuwien.ac.at

Thx in advance,
Aram

bohluly July 10, 2009 09:22

sample of fortran program
 
source_kEx(ij)= gen ! explicit source of k
source_kIm(ij)= -Cmu(ij)*k1/ (nut(ij)+.000000001) ! implicit source of k

cturb1 = 1.44d0 ; cturb2 = 1.92d0

k_t0 = k_t(ij)+.0000001
ep_0 = ep_(ij)

source_eEx(ij)= cturb1 * ep_0 / k_t0 * gen ! explicit source of e
source_eIm(ij)= -cturb2 * ep_0 / k_t0 ! implicit source of e

.
.
.
! source term k
do ij=1,no_nodes
k_t(ij) = ( k_t(ij) + source_kEx(ij) *dt) / (1.-dt*source_kIm(ij))
enddo
! source term e
do ij=1,no_nodes
ep_(ij) = ( ep_(ij) + source_eEx(ij) *dt) / (1.-dt*source_eIm(ij))
enddo

hadian July 11, 2009 04:26

would you please put the full title and address of the paper here?

idefix May 23, 2013 02:46

Hello together,

even the thread is old I hope somebody is reading it

I want to add a source term in the epsilon equation in the k-epsilon-model

The term is:

4 * k * C_mu * HLP

with:
HLP = (du/dx)^2 + (dv/dy)^2 + (dw/dz)^2 + 1/2 * (du/dy + dv/dx)^2 + 1/2 * (du/dz + dw/dx)^2 + 1/2 * (dv/dz + dw/dy)^2

After adding this term to the epsilon-equation it looks like:
+ fvm::SuSp(4.0*k_*Cmu_*magSqr(symm(fvc::grad(U_)))/(epsilon_+const), epsilon_)

with const = dimensiond scalar (1e-05) to avoid dividing by 0

Is it correct to implement this term like this?
Iīve read: http://www.cfd-online.com/Wiki/Sourc..._linearization
but I donīt know how to divide my term in a constant and a linear part.

Can anybody help?
thanks a lot

greetings
Idefix

cfdman_aero June 6, 2013 11:00

Prof. Dick's paper
 
Quote:

Originally Posted by ganesh
;42758
Dear khaiching,

There is a paper by Prof. Dick's group on linearisation of source terms for k-epsilon and k-w equations. I can mail it to you if you give your mail id

Regards,

Ganesh

Dear ganesh,

It would be my pleasure if you send me that paper via e-mail. My e-mail: ali_or_aero@yahoo.com


All times are GMT -4. The time now is 18:28.