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kantored March 23, 2007 04:35

a propeller 2 way fsi
hello i got a big problem to solve and i get too many error ... well i need to create a 2 way fsi of a propeller how it simulate in the water as it revolves ,

i create the propeller and the axis of the propeller and i did what exactly the tutorial 21 is says ... what is my problem??? the cfx get an error writing that the structural has an error... it can not make any solution... this is because i did not put the boundaries conditions good ....

and i am asking what boundary contitions should i put ??? i put a revolve velocity only on the propeller nothing else .. so the propeller should revolve in the simulator then export the results to cfx .. cfx make the cfd then export to simulations and simulation to create the structural...

but it is not working....

please for any solution

stogianos March 23, 2007 08:52

Re: a propeller 2 way fsi
i did not understand, what exactly you want to do!!!

kantored March 23, 2007 08:56

Re: a propeller 2 way fsi
i want to simulate a propeller in ansys simulation and ansys cfx , listen how the story goes .... i design the propeller and do all the steps in simulation, then export the .inp file and create the multifield in cfx.... but i do not know what boundaries conditions to put in designspace. shall i put rotational velocity????? torgue??? how can i make this propel to rotate in simulation environment ???????

Johnny March 24, 2007 01:00

Re: a propeller 2 way fsi
see CFX tutorial 12 and 23 about rotating domains.

kantored March 26, 2007 05:29

Re: a propeller 2 way fsi
i saw the tutorial.. but i have a question, how we apply rotating frames in cfx??

Stumpy April 5, 2007 09:24

Re: a propeller 2 way fsi
Firstly, why do you want to do a 2-way FSI of a propeller? I would expect the deformations to be minimal and not effect the fluid flow, is this the case? If you just want to know the stress in the propeller due to the fluid forces and rotational structural forces then 1-way FSI is more appropriate. If the expected deformations of the propeller actually change the fluid flow then you do need 2-way FSI.

kantored April 6, 2007 17:20

Re: a propeller 2 way fsi
no the flow is not change the deformation of thepropeller so much. i want to see the flow of the water due to the rotation of the propeller. what are you saing ?? to apply rotation frame and then apply the results to the simulation (1 way)?? how can i make rotation frames ??? if i do not nees otation frames , how shall i put the contitions?

thanks a lot kanto reduress

Stumpy April 9, 2007 14:12

Re: a propeller 2 way fsi
Are you even interested in the stress in the propeller? If not, then this is not an FSI problem, it's just a plain old rotating machine simulation - fluids onlt. Take a look through the Axial Rotor-Stator tutorial, this is essential the same as a propeller except that you have an additional stationary component.

kantored April 11, 2007 12:00

Re: a propeller 2 way fsi
yes i am interesting to know the stress of the propeller it revolves ... so the only problem is how to put a rotation of the propeller in the simulation tab. do you believe it is better to do this in 1 way fsi???

best regards

Stumpy April 11, 2007 14:51

Re: a propeller 2 way fsi
Yes, do 1-way FSI. So solve the fluids side in a similar way to the Axial Rotor-Stator tutorial. Then in Simulation map those forces on to your solid mesh (to do this you just apply it like any other load and you will be asked for the CFX .res file). You can then add the rotational force in Simulation. This doesn't actually rotate your mesh, it just adds the forces due to rotation. Hope this helps.

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