Rotating A turbine Blade

charlestchan · August 28, 2011, 05:36

I have manage to simulate a vortex in a cyclinder tank, however, i have no idea how should i make the blade rotate due to the vortex impact. I attached a few picture to make my explanation clearer.

http://imageshack.us/photo/my-images...imulation.jpg/

http://imageshack.us/photo/my-images...xample2up.jpg/

I still can't get the blade to turn from the flow of water, anyone can help me?

ghorrocks · August 28, 2011, 07:37

If you are looking for the steady state solution to this the easiest way is to guess a rotation speed and run the model. Then guess another speed and get another result. You will start generating points on the torque versus speed characteristic for your device, and once you know the curve well enough you can interpolate to zero net torque which is you operating point.

This approach is much easier than trying to get the simulation to converge on a rotor speed.

charlestchan · August 28, 2011, 07:44

thanks for your help

charlestchan · August 28, 2011, 07:47

This is how i do it. I draw the tank and blade separately in catia, then i import them into ansys. After that, i mesh both of them together. I set Fluid as domain 1, where i can set the inlet, outlet and wall. Then i set The blade as immersed solid domain 2, and i put it rotating as certain rpm. Am i on track or am i wrong?

ghorrocks · August 28, 2011, 08:05

Close but no. Do not use the immersed solid approach. Use a rotating frame of reference approach. See the RFR examples in the CFX tutorials for tips on how to set it up.

charlestchan · August 28, 2011, 08:11

I'll check out on that. Thanks ghorrocks.. can i pm u when i'm stuck again?

ghorrocks · August 28, 2011, 08:18

Please put general questions on the forum. This is so other people can have their say if they want, and so people can see the answers if they want.

Keep PM for messages which are actually private.

charlestchan · August 28, 2011, 09:51

My university doesn't want to share the tutorial files for ansys cfx, but i heard that i can learn about rotating frame reference from the vertical turbine tutorial, do u know where i can get it?

charlestchan · August 28, 2011, 15:22

May i ask u again, whether the fluid should be rotating? or the blade? i mean when i'm setting up Moving reference frame.

charlestchan · August 28, 2011, 17:42

Fluent is not user friendly as CFX.. i have trouble identifying the parts as it is not highlighted in FLUENT

ghorrocks · August 28, 2011, 19:48

The CFX tutorials are all installed with CFX. From the launcher, help/CFX/Tutorials.

charlestchan · August 29, 2011, 00:11

thanks man.. i'll try again

charlestchan · August 31, 2011, 04:15

Firstly, i have no idea how to set a rotating frame, second, i don't know where to see the torque vs speed graph, lastly, i don't know how to use CEL. Anyone can provide screenshot to guide me a little? please?

charlestchan · August 31, 2011, 04:17

The turbine is attached to a generator, so , in order to measure the efficiency of the turbine from Ansys, it is possible to assume that the turbine is rotating as simulated right? Or will there be any other effects in real life set up?

ghorrocks · August 31, 2011, 07:51

As I said earlier look at the rotating frame of reference tutorial example. Also read the turbomachinery best practices guide.

charlestchan · September 8, 2011, 06:07

Do i need to set an opening boundary? I've set inlet , outlet and wall.

ghorrocks · September 8, 2011, 08:47

Inlet, outlet and wall should be OK, but I do not know the detail of what you are doing so cannot be definite about it.

charlestchan · September 10, 2011, 15:39

How do i animate the solid domain rotation? i only can animate streamline which is insufficient.

ghorrocks · September 12, 2011, 21:05

If you did this model as transient rotor/stator then making an animation with a rotating rotor is easy. If you did this model as frozen rotor then it will not be possible as your simulation is just a snapshot at that rotation position.

charlestchan · September 13, 2011, 05:59

I've already set the analysis type to transient.. but i still don't see how the immersed solid going to rotate.. any idea?

August 28, 2011, 05:36	Rotating A turbine Blade	#1
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	I have manage to simulate a vortex in a cyclinder tank, however, i have no idea how should i make the blade rotate due to the vortex impact. I attached a few picture to make my explanation clearer. http://imageshack.us/photo/my-images...imulation.jpg/ http://imageshack.us/photo/my-images...xample2up.jpg/ I still can't get the blade to turn from the flow of water, anyone can help me? Last edited by wyldckat; September 3, 2015 at 18:51. Reason: disabled embedded images

August 28, 2011, 08:18		#7
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Please put general questions on the forum. This is so other people can have their say if they want, and so people can see the answers if they want. Keep PM for messages which are actually private. lanz_mr likes this.

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August 28, 2011, 07:37		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	If you are looking for the steady state solution to this the easiest way is to guess a rotation speed and run the model. Then guess another speed and get another result. You will start generating points on the torque versus speed characteristic for your device, and once you know the curve well enough you can interpolate to zero net torque which is you operating point. This approach is much easier than trying to get the simulation to converge on a rotor speed.

August 28, 2011, 07:44		#3
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	thanks for your help

August 28, 2011, 07:47		#4
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	This is how i do it. I draw the tank and blade separately in catia, then i import them into ansys. After that, i mesh both of them together. I set Fluid as domain 1, where i can set the inlet, outlet and wall. Then i set The blade as immersed solid domain 2, and i put it rotating as certain rpm. Am i on track or am i wrong?

August 28, 2011, 08:05		#5
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Close but no. Do not use the immersed solid approach. Use a rotating frame of reference approach. See the RFR examples in the CFX tutorials for tips on how to set it up.

August 28, 2011, 08:11		#6
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	I'll check out on that. Thanks ghorrocks.. can i pm u when i'm stuck again?

August 28, 2011, 09:51		#8
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	My university doesn't want to share the tutorial files for ansys cfx, but i heard that i can learn about rotating frame reference from the vertical turbine tutorial, do u know where i can get it?

August 28, 2011, 15:22		#9
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	May i ask u again, whether the fluid should be rotating? or the blade? i mean when i'm setting up Moving reference frame.

August 28, 2011, 17:42		#10
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	Fluent is not user friendly as CFX.. i have trouble identifying the parts as it is not highlighted in FLUENT

August 28, 2011, 19:48		#11
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	The CFX tutorials are all installed with CFX. From the launcher, help/CFX/Tutorials.

August 29, 2011, 00:11		#12
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	thanks man.. i'll try again

August 31, 2011, 04:15		#13
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	Firstly, i have no idea how to set a rotating frame, second, i don't know where to see the torque vs speed graph, lastly, i don't know how to use CEL. Anyone can provide screenshot to guide me a little? please?

August 31, 2011, 04:17		#14
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	The turbine is attached to a generator, so , in order to measure the efficiency of the turbine from Ansys, it is possible to assume that the turbine is rotating as simulated right? Or will there be any other effects in real life set up?

August 31, 2011, 07:51		#15
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	As I said earlier look at the rotating frame of reference tutorial example. Also read the turbomachinery best practices guide.

September 8, 2011, 06:07		#16
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	Do i need to set an opening boundary? I've set inlet , outlet and wall.

September 8, 2011, 08:47		#17
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Inlet, outlet and wall should be OK, but I do not know the detail of what you are doing so cannot be definite about it.

September 10, 2011, 15:39		#18
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	How do i animate the solid domain rotation? i only can animate streamline which is insufficient.

September 12, 2011, 21:05		#19
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	If you did this model as transient rotor/stator then making an animation with a rotating rotor is easy. If you did this model as frozen rotor then it will not be possible as your simulation is just a snapshot at that rotation position.

September 13, 2011, 05:59		#20
charlestchan New Member Join Date: Jul 2011 Posts: 16 Rep Power: 15	I've already set the analysis type to transient.. but i still don't see how the immersed solid going to rotate.. any idea?