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#1 |
New Member
Furkan Türkmen
Join Date: May 2021
Posts: 7
Rep Power: 5 ![]() |
Hello sir,
When I use the floating body solver options, I get the following forces from the file REEF3D_6DOF_S_force.dat. Normally, my expectation is that Fz is close to +3000N which is the weight of the ship but as you can see from the figure, the z force convergences to zero. So, I think this parameters mean something else such as net force on floating body. Could you tell me what do they mean? (also Ks Ms Ns) In addition I would like to see both viscous and pressure force, is there any possibilities to do that? Thank you, Best regards p { margin-bottom: 0.1in; line-height: 120% } |
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#2 |
Senior Member
Arun Kamath
Join Date: Nov 2014
Location: Trondheim, Norway
Posts: 265
Rep Power: 13 ![]() |
Dear Furkan,
From the filename that you name, I see that you are not using the newest version of the floating algorithm implemented in the model. I would advice you to get the latest version from Github (there will also be a new release soon). In addition, if you see this persists, it would be useful to have a look at your input files.
__________________
Arun X years with REEF3D |
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#3 |
New Member
Furkan Türkmen
Join Date: May 2021
Posts: 7
Rep Power: 5 ![]() |
Thank you very much. I will look for the newest version.
Regards |
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#4 |
New Member
Furkan Türkmen
Join Date: May 2021
Posts: 7
Rep Power: 5 ![]() |
Hello again Mr Kamath,
I have tried to solve floating body problem with the latest version, however, the result have not converged. The critical velocity was exceeded. I used the direct forcing setting for X 13 (X 13 2) and as you mentioned before, I saw that the forces.dat file is new notation now, which is more clear, thank you. Am I missing something for the solution I think. If there were a example case I would compare with it. Will you do a tutorial case for floating body? In attachment you can find my case settings Thank you, Best regards Furkan |
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#5 |
New Member
Join Date: Mar 2021
Posts: 8
Rep Power: 5 ![]() |
Dear Furkan,
we can have a look, but you need to send us the stl file as well so that we can run the actual simulation. |
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#6 |
New Member
Furkan Türkmen
Join Date: May 2021
Posts: 7
Rep Power: 5 ![]() |
Hello Dr Martin,
I want to simulate a ship resistance analyze as you can see in the attached picture. My main objective is to get the x direction forces on the floating body. When the 6DOF is not allowed i can get the forces as i want. They are strongly acceptable. When 6DOF is allowed i cannot get the forces. In 6 DOF analyzes i want these: Translation through x axis is not allowed. Translation through y axis is not allowed. Translation through z axis is allowed. Rotation around x axis is not allowed. Rotation around y axis is allowed. Rotation around z axis is not allowed. The mass is 320kg. The center of rotation is 5.66643,4,2.4297 (as meter). The moment of inertia values are 38.44, 357.24, 357.24. I am sending you the control.txt and ctrl.txt and floatig.stl files. In this situation i do not get any error. And i can get free surface as i want. But i cannot read the x direction forces on the body. In this situation REEF3D_6DOF_S_force.dat folder is created. There are Xs, Ys, Zs, Ks, Ms, Ns. But their values are not as i expect. They all goes to zero. When i change X 13 0 option to X 13 2 the solution diverges. I also tried different options for X 40. But could not get the x direction forces on the floating body. In my opinion my mistakes are in X 10, X 13, X 40 options. Could you please help me? What should i change in my ctrl.txt file to get the x direction forces on the hull (ship resistance value)? By the way i use version 21.02. In addition, I can not send stl file due to size is too large. I have sent you an e mail to your mail address (tobias.martin@ntnu.no) Best regards. Last edited by fturkmen; May 31, 2021 at 09:57. |
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Tags |
floating body, floating body forces |
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