[gxy200992243]

Hi, everyone!

I am now trying to use pisofoam combined with les (oneeqeddy) to simulate wind turbine wake with the help of actuator line method. I find almost all the les tutorials provided by openfoam are using oneeqeddy. Now I am facing the problem to convert the les model from oneeqeddy to smagorinsky. What changes do I have to make in fvschemes, fvsolution and "0" directory? I am using OF 2.2.1.

Billions of thanks!

[RodriguezFatz]

You don't have any "k" equation in smagorinsky, so you don't need all the information about k any longer. Such as fvschemes: gradient, div(phi,k),... or in the \0 directory the "k" file and so on. But it also doesn't matter if you just keep it, openFOAM doesn't care about too much information.

You need to change the LESModel to smagorinsky by setting constant\LESProperties file the relevant line to

LESModel Smagorinsky;

[gxy200992243]

Hi, Philipp!

Thank you very much for your reply! Your information really helps me a lot!

[ruby_nuaa]

hi sorry to bother you . I'm quite interested in actuator line method. As far as I know,OF only has actuator disk model(OF 2.2.2),so ,did you add it yourself ? How? I've read the report of Svenning's AD implementation for OF1.5 . I want to modify it into AL,but I'm not sure the code works for 2.2.2 . Any suggestion?
best regards
ruby

[gxy200992243]

Yes, I added it by myself. I have read the report of Svenning, but my interpretation of AL is a little different from his. I think the major difference between AD and AL is that the body force in AL changes with time, so I think no big change is needed, but you have to add runtime as a parameter in the function in which body force is calculated.

Are you from Nan Hang?

[ruby_nuaa]

Hi thks for your reply. And yes,I'm from Nan Hang,well,NUAA is better. The time-varying bodyforce part , i get it. The thing is that i don't really know how to extract those cells that the "line" lies in . Are there any functions for this? How do you know the length of each segment in the cells? Cause the code in Svenning's report is a bit old, the OF code changes a lot. I'm a little lost here. Could you help me?

best regards
ruby

[gxy200992243]

As I said, my interpretation of actuator line is different from Svenning's, so I do not have to know which cells the lines lie in. In Svenning's report, he used the fan boundary condition to deal with the sudden jump or singularity brought by the body force. The fan boundary condition requires you to know which cells the lines lie in. In my interpretation, I use Gaussian Weight Function to smooth the jump or singularity, so no special boundary condition is needed.

You can google these two PhD dissertations: " Actuator Disc Method Used in Wind Turbine " and " Actuator line modeling of wind turbine wakes ". They give incredibly detailed explanation about actuator disk and actuator line. If you are still confused about their method, you can also read their journal papers. My interpretation of actuator line is the same as theirs.

Now I have a question about the actuator line simulation. Can you help me with it? http://www.cfd-online.com/Forums/ope...imulation.html

[ruby_nuaa]

Originally Posted by gxy200992243

As I said, my interpretation of actuator line is different from Svenning's, so I do not have to know which cells the lines lie in. In Svenning's report, he used the fan boundary condition to deal with the sudden jump or singularity brought by the body force. The fan boundary condition requires you to know which cells the lines lie in. In my interpretation, I use Gaussian Weight Function to smooth the jump or singularity, so no special boundary condition is needed.

You can google these two PhD dissertations: " Actuator Disc Method Used in Wind Turbine " and " Actuator line modeling of wind turbine wakes ". They give incredibly detailed explanation about actuator disk and actuator line. If you are still confused about their method, you can also read their journal papers. My interpretation of actuator line is the same as theirs.

Now I have a question about the actuator line simulation. Can you help me with it? http://www.cfd-online.com/Forums/ope...imulation.html

Hi
I'm sorry for this late reply. Your information helps me a lot!! Thank you very much.
As for the problem in your new thread , maybe you should compare your OF data with the experimental data first ? I don't have a clue about the fvschemes, i might just try one by one.... Sorry .
best wishes
Ruby

[gxy200992243]

Thank you for your reply! I just worked it out. The results are very similar to the experiment data.