decay 2d turbulence - the initial field

mp121209 · February 25, 2013, 18:21

I've seen some videos that demonstrates the process of 2d turbulence decay. Here are some of them:
http://www.youtube.com/watch?v=boWeyfYs2EQ
http://www.youtube.com/watch?v=pNCst5-zPEQ
http://www.youtube.com/watch?v=-fDwnyi_EkM

I want to simulate this process by using the Euler system of equations. For this goal, I must have the initial field (rho, u, w, p).

Does anyone give me some ideas about this?

Thanks for helping!

FMDenaro · February 26, 2013, 03:45

Quote:

Originally Posted by mp121209

I've seen some videos that demonstrates the process of 2d turbulence decay. Here are some of them:
http://www.youtube.com/watch?v=boWeyfYs2EQ
http://www.youtube.com/watch?v=pNCst5-zPEQ
http://www.youtube.com/watch?v=-fDwnyi_EkM

I want to simulate this process by using the Euler system of equations. For this goal, I must have the initial field (rho, u, w, p).

Does anyone give me some ideas about this?

Thanks for helping!

try to see in the books of Lesieur ...
just to say that if you use the inviscid flow equation, you have no decay due to dissipation. Furthermore, in 2D you can have some inverse cascade as well as you can see small vortical structures forming bigger ones (e.g., the vortex merging)

mp121209 · February 26, 2013, 04:12

Can you give me the link to that book you sad?
I know that there is no decay due to physical dissipation in inviscid flow, but it's impossible to neglect the grid viscosity which is mesh-dependent factor. I don't know what kind of the final field will be, I'm interested in generating the initial field to initialize the test case.
Thanks for replying!

FMDenaro · February 26, 2013, 04:22

http://www.amazon.com/Turbulence-Flu...der_1402064349

mp121209 · February 26, 2013, 05:29

OK, that book explains the theory of turbulence very good and fully. But I still need particular specifically formulas for generating the initial field to initialize a simulation case. In the book I can't find out them.

FMDenaro · February 26, 2013, 05:34

see also:

http://onlinelibrary.wiley.com/doi/1...d.613/abstract

in the references you will find a paper of Lesiuer describing the details

mp121209 · February 26, 2013, 05:57

Can you tell the name of Lesiuer's paper describing the details of turbulence initial field for numerical simulations?
I couldn't download the journal.

FMDenaro · February 26, 2013, 06:05

Lesieur, M. Staquet C, Le Roy P, Comte P. The mixing layer and its coherence examined from the point of
view of two-dimensional turbulence. Journal of Fluid Mechanics 1986; 192:511–534.

you cna find the case of the initialization for a 2D micing layer

mp121209 · February 26, 2013, 06:59

Do you know that I don't need an initial field for 2D shear layer. I need an initial field for the exactly given above examples: decay of 2D turbulence flow with vortices. I've found out some articles, which describe the initial field for some different kind of Euler equations. They used the vortex-velocity transport equations to solve the problem. With that kind of Euler equations it's possible to define the exact field for all the vortices. I use the Euler equations in FV method to solve the problem, I need the initial state for all components of the velocity. This is my problem!
Thanks for helping!

FMDenaro · February 26, 2013, 08:14

Quote:

Originally Posted by mp121209

Do you know that I don't need an initial field for 2D shear layer. I need an initial field for the exactly given above examples: decay of 2D turbulence flow with vortices. I've found out some articles, which describe the initial field for some different kind of Euler equations. They used the vortex-velocity transport equations to solve the problem. With that kind of Euler equations it's possible to define the exact field for all the vortices. I use the Euler equations in FV method to solve the problem, I need the initial state for all components of the velocity. This is my problem!
Thanks for helping!

if you want to simulate only the homogeneous/isotropic decay, you can simply work in the x,y plane by using the initial 1D distribution (extended in the homogeneous 2D meaning and adjusting the coefficients to satisfy the continuity contraint) described here:

On the application of congruent upwind discretizations for large eddy simulations

Authors
Andrea Aprovitola, Filippo Maria Denaro

Publication date
2004/2/10

Journal name
Journal of Computational Physics

Volume
194

Issue
1

Pages
329-343

Publisher
Academic Press

mp121209 · February 26, 2013, 16:25

I want to solve the problem in the x,y plane, with the limited space [LxL] and periodic boundary conditions. I need the initial with vorticies like in the above videos. But I can't find out some formulas for this purpose. I've read the article you sad, but it didn't help me.
I think that in the videos, the vortex-velocity form of the Euler equations was used. It's possible to give the exact values of vorticies at the cell centers. I use the FV approach to solve the the Euler system of equations. It's no need to have a vorticity field at the beginning time. But I need the beginning values for the velocity components.
I have read many works, but I can't find out some of them helpful for me!

AHutchison · May 7, 2013, 00:39

@mp121209 did you have any luck with your simulation?

triple_r · May 7, 2013, 10:36

I don't know if you are still interested in this or not, but you can find an initial velocity field for homogenous turbulence in the following paper:

Numerical Experiments in Homogeneous Turbulence, by Robert S. Rogallo

It is a very old NASA report and a very good reference for DNS codes, so it is available on many sites. Just google the title and you should be able to get it. I can't remember which page :-p but it was near the end of the paper. It uses Fourier transform though, so you should be prepared to take inverse FFT of a spectral distribution, just a heads up :-)

Good luck.

February 25, 2013, 18:21	decay 2d turbulence - the initial field	#1
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 3	I've seen some videos that demonstrates the process of 2d turbulence decay. Here are some of them: http://www.youtube.com/watch?v=boWeyfYs2EQ http://www.youtube.com/watch?v=pNCst5-zPEQ http://www.youtube.com/watch?v=-fDwnyi_EkM I want to simulate this process by using the Euler system of equations. For this goal, I must have the initial field (rho, u, w, p). Does anyone give me some ideas about this? Thanks for helping!

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
pisoFoam - unstable pressure residual	Industrial_CFD	OpenFOAM Running, Solving & CFD	21	February 24, 2013 15:39
problem with Min/max rho	tH3f0rC3	OpenFOAM	7	February 23, 2013 05:37
Error while running rhoPisoFoam..	nileshjrane	OpenFOAM Running, Solving & CFD	8	August 26, 2010 12:50
lift and drag on ship superstructures	vaina74	OpenFOAM Running, Solving & CFD	3	June 8, 2010 12:30
ForcesCoeffs	ronaldo	OpenFOAM	4	September 14, 2009 07:11

February 26, 2013, 04:12		#3
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 3	Can you give me the link to that book you sad? I know that there is no decay due to physical dissipation in inviscid flow, but it's impossible to neglect the grid viscosity which is mesh-dependent factor. I don't know what kind of the final field will be, I'm interested in generating the initial field to initialize the test case. Thanks for replying!

February 26, 2013, 04:22		#4
FMDenaro Senior Member Filippo Maria Denaro Join Date: Jul 2010 Posts: 576 Rep Power: 10	http://www.amazon.com/Turbulence-Flu...der_1402064349

February 26, 2013, 05:29		#5
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 3	OK, that book explains the theory of turbulence very good and fully. But I still need particular specifically formulas for generating the initial field to initialize a simulation case. In the book I can't find out them.

February 26, 2013, 05:34		#6
FMDenaro Senior Member Filippo Maria Denaro Join Date: Jul 2010 Posts: 576 Rep Power: 10	see also: http://onlinelibrary.wiley.com/doi/1...d.613/abstract in the references you will find a paper of Lesiuer describing the details

February 26, 2013, 05:57		#7
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 3	Can you tell the name of Lesiuer's paper describing the details of turbulence initial field for numerical simulations? I couldn't download the journal.

February 26, 2013, 06:05		#8
FMDenaro Senior Member Filippo Maria Denaro Join Date: Jul 2010 Posts: 576 Rep Power: 10	Lesieur, M. Staquet C, Le Roy P, Comte P. The mixing layer and its coherence examined from the point of view of two-dimensional turbulence. Journal of Fluid Mechanics 1986; 192:511–534. you cna find the case of the initialization for a 2D micing layer

February 26, 2013, 06:59		#9
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 3	Do you know that I don't need an initial field for 2D shear layer. I need an initial field for the exactly given above examples: decay of 2D turbulence flow with vortices. I've found out some articles, which describe the initial field for some different kind of Euler equations. They used the vortex-velocity transport equations to solve the problem. With that kind of Euler equations it's possible to define the exact field for all the vortices. I use the Euler equations in FV method to solve the problem, I need the initial state for all components of the velocity. This is my problem! Thanks for helping!

February 26, 2013, 16:25		#11
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 3	I want to solve the problem in the x,y plane, with the limited space [LxL] and periodic boundary conditions. I need the initial with vorticies like in the above videos. But I can't find out some formulas for this purpose. I've read the article you sad, but it didn't help me. I think that in the videos, the vortex-velocity form of the Euler equations was used. It's possible to give the exact values of vorticies at the cell centers. I use the FV approach to solve the the Euler system of equations. It's no need to have a vorticity field at the beginning time. But I need the beginning values for the velocity components. I have read many works, but I can't find out some of them helpful for me!

May 7, 2013, 00:39		#12
AHutchison New Member Angus Hutchison Join Date: May 2013 Posts: 1 Rep Power: 0	@mp121209 did you have any luck with your simulation?

May 7, 2013, 10:36		#13
triple_r Member Reza Join Date: Mar 2009 Location: Appleton, WI Posts: 49 Rep Power: 6	I don't know if you are still interested in this or not, but you can find an initial velocity field for homogenous turbulence in the following paper: Numerical Experiments in Homogeneous Turbulence, by Robert S. Rogallo It is a very old NASA report and a very good reference for DNS codes, so it is available on many sites. Just google the title and you should be able to get it. I can't remember which page :-p but it was near the end of the paper. It uses Fourier transform though, so you should be prepared to take inverse FFT of a spectral distribution, just a heads up :-) Good luck.