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Using 6dof for 3D turbine rotation

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Old   February 25, 2014, 02:24
Default Using 6dof for 3D turbine rotation
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Hi, I am working on a problem where I have a turbine driven by the flow. My intention is to use 6dof and rotate the turbine along with the enclosed zone (similar to what we do in sliding mesh where layering, smoothing and remeshing will not take place).
The approach I am doing is
1. hooking 6dof to Turbine (which is defined as wall in BC) with 6dof-on, passive-off

2. Hooking 6dof to fluid Zone enclosing the turbine (which has all exterior surfaces defined as interface). The only wall inside the zone is turbine. here 6dof-on, passive-on

Will this kind of a strategy calculate fluid forces and moments on the turbine and rotate the turbine along with the zone enclosing it?

My axis of rotation is Y and I am restricting the all translation and x,z rotation using

prop[SDOF_LOAD_LOCAL] = TRUE;
prop[SDOF_ZERO_TRANS_X] = TRUE;
prop[SDOF_ZERO_TRANS_Y] = TRUE;
prop[SDOF_ZERO_TRANS_Z] = TRUE;
prop[SDOF_ZERO_ROT_X] = TRUE;
prop[SDOF_ZERO_ROT_Z] = TRUE;

Please discuss if you have some thoughts..
Mithun MG
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Old   March 25, 2014, 00:25
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I am working on something very similar. I have a turbine in a pipe with a rotating zone around the rotor.

Have you made progress with your simulation? Did it work?
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Old   February 29, 2016, 09:38
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Yes I have managed to simulate this.
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Old   October 23, 2016, 06:37
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Quote:
Originally Posted by mg.mithun View Post
Yes I have managed to simulate this.
Hi mithun,
i am working on sth as you have done
but i too have some problems
1, i was intended to simulate the deaccelerating procedure of the turbine,how can i define the initial rotorary speed of the turbine?
2, shall the 6dof udf be hooked to the zone or the boundry of the turbine, or both?
Thank u very much
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Old   October 24, 2016, 13:49
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Quote:
Originally Posted by jealor View Post
Hi mithun,
i am working on sth as you have done
but i too have some problems
1, i was intended to simulate the deaccelerating procedure of the turbine,how can i define the initial rotorary speed of the turbine?
2, shall the 6dof udf be hooked to the zone or the boundry of the turbine, or both?
Thank u very much
Hi Klxing

1) Set a value for "rigid body angular velocity" which will be you initial rotation speed
2) I hooked the UDF to both zone and boundary. You have to make sure that you keep "Passive" ON when you hook for zone and "Passive" off when you hook on boundary.

Hope this helps. Do post in the forum if it worked for you
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Old   October 24, 2016, 21:43
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Originally Posted by mg.mithun View Post
Hi Klxing

1) Set a value for "rigid body angular velocity" which will be you initial rotation speed
2) I hooked the UDF to both zone and boundary. You have to make sure that you keep "Passive" ON when you hook for zone and "Passive" off when you hook on boundary.

Hope this helps. Do post in the forum if it worked for you
Hi,
i set "rigid body angular velocity" to 1800rpm as the initial value, but when i preview the mesh motion, the angular velocity seems to be constant(1800rpm),which means that the torque if the fluid does not take effect.
it maybe caused by math errors since the history can only record the degree of the rotor,and i have to compute the angular velocity in EXCEL
So i'm not sure what the reason might be . I will try to hook the UDF to wall boundries first, as u said, to see whether it works.
I will keep the status, Thank u very much
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Old   November 7, 2016, 07:44
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Quote:
Originally Posted by mg.mithun View Post
Hi Klxing

1) Set a value for "rigid body angular velocity" which will be you initial rotation speed
2) I hooked the UDF to both zone and boundary. You have to make sure that you keep "Passive" ON when you hook for zone and "Passive" off when you hook on boundary.

Hope this helps. Do post in the forum if it worked for you
i am here to update my situation
i set the case the way u said, set the fluid field and the boundary seperately with the same 6DOF marco, and set the field to 'passive'
it seems to work now, but it is still calculating
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