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-   -   Vortex-induced Vibration (VIV) (http://www.cfd-online.com/Forums/flow-3d/102608-vortex-induced-vibration-viv.html)

ariza May 29, 2012 19:41

Vortex-induced Vibration (VIV)
 
hai guys.
I was a student last semester. I am currently working on final project with the topic of large-diameter cylinder viv in force due to currents and wave forces. I'm using a flow-3d for the simulation of vortex shedding. but until now I can not how.

whether there are any of you guys can help me? provide solutions or suggestions how?

thanks for the help.:)

hans_ina August 6, 2012 01:16

Quote:

Originally Posted by ariza (Post 363691)
hai guys.
I was a student last semester. I am currently working on final project with the topic of large-diameter cylinder viv in force due to currents and wave forces. I'm using a flow-3d for the simulation of vortex shedding. but until now I can not how.

whether there are any of you guys can help me? provide solutions or suggestions how?

thanks for the help.:)

Hi Ariza,

what you mean of VIV is vibration due current around cylinder? :)
can you specified your question about? its your problem on modelling or meshing or else? please specified.

Thanks,
Hans

ariza August 6, 2012 20:11

In my Case,
VIV occurs because the combination of currents and waves.
then, how steps to make simulation with Flow3D?
such as modelling, input, solution, output...

thx for your attention...

hans_ina August 6, 2012 21:23

For modeling, you can input the parameter (read manual handbook) then fill the BC with inlet and outlet as outflow.

Put the parameter and fill current and wave value (note: use free surface for input wave value)

hope this helpfull for your thesis. :)

ariza August 6, 2012 22:46

Quote:

Originally Posted by hans_ina (Post 375690)
For modeling, you can input the parameter (read manual handbook) then fill the BC with inlet and outlet as outflow.

Put the parameter and fill current and wave value (note: use free surface for input wave value)

hope this helpfull for your thesis. :)

thx a lot..
now i've finished my final exam..
23 september is my graduation..
:)

hossein2357 October 24, 2012 10:41

Quote:

Originally Posted by hans_ina (Post 375690)
For modeling, you can input the parameter (read manual handbook) then fill the BC with inlet and outlet as outflow.

Put the parameter and fill current and wave value (note: use free surface for input wave value)

hope this helpfull for your thesis. :)

******
hi, i dont underestand"read manual handbook"
which handbook?

hossein2357 October 24, 2012 11:28

i simulated cylindric in sea. but i dont know, how i can obtain "vortex" .


'vortex induce vibrating'

hans_ina October 24, 2012 21:32

Quote:

Originally Posted by hossein2357 (Post 388315)
******
hi, i dont underestand"read manual handbook"
which handbook?

Quote:

Originally Posted by hossein2357 (Post 388327)
i simulated cylindric in sea. but i dont know, how i can obtain "vortex" .


'vortex induce vibrating'

Hi,

You can find it on help menu guy.

mali May 31, 2013 00:11

Hi All,

I think for simulating vortex induced vibration of a bluff body (exm: circular) can be done using the similar case of wingMotion in the tutorial. I had simulated a circular cylinder using pimpleDyMFoam, and it worked for small reduced velocity u* < 1, but it blowed up at higher reduced velocity. I suspected this happened because the system was in resonance, so the vibration was very high in amplitude, where I can saw the mesh changed badly at that time.

If you have suggestion on how I can simulate the VIV problem for high reduced velocity, please let me know.

Cheers
-mali-

hans_ina May 31, 2013 06:29

Quote:

Originally Posted by mali (Post 431109)
Hi All,

I think for simulating vortex induced vibration of a bluff body (exm: circular) can be done using the similar case of wingMotion in the tutorial. I had simulated a circular cylinder using pimpleDyMFoam, and it worked for small reduced velocity u* < 1, but it blowed up at higher reduced velocity. I suspected this happened because the system was in resonance, so the vibration was very high in amplitude, where I can saw the mesh changed badly at that time.

If you have suggestion on how I can simulate the VIV problem for high reduced velocity, please let me know.

Cheers
-mali-

what case you study?

mali June 1, 2013 00:25

Hi hans_ina,

Thanks for your replay.

I used 2D rigid circular cylinder attached with a vertical spring. Re based on diameter of the cylinder was in the range of 3000 to 22000, depending on the value of reduced velocity. For the elastic system, the mass ratio was 2.4 and the damping ratio is 0.0054 , similar to the case of Khalak and Williamson [1996].

Cheers,

hossein2357 July 5, 2013 08:42

damper
 
Hi friend:)
do you know, how can add damper for Cylinder in viv research or other work.
we want simulate moving object with damper, but we dont know how we can add damper to object.

mikkysaik July 8, 2013 09:58

3D mesh
 
1 Attachment(s)
Hi all. I am trying to model 3D flow around a cylinder using ANSYS fluent. I need info on how to generate a 3D mesh. I tried generating the geometry but got stuck. please I need info on how to go about it.


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