domains for fan

c120613 · April 12, 2010, 08:21

Dear all,

I was simulating a fan and 3 components have been included. these components from the inlet to the outlet of the fan compressor are (see the attached file):

- inlet part which is identified as rotor and includes the initial part of the nose from r=0;
- rotor part where is possible to identify the rotor blades of the fan;
- stator where is possible to look the stator blades.

However I'm not sure that this case can work because for only one stage we are using 3 domain instead of two (rotor and stator only).

Somebody knows if my solution is fine or not?

Kind regards

Domenico

ghorrocks · April 12, 2010, 18:33

It should work fine. Why do you suspect it does not work?

Attesz · April 14, 2010, 07:19

why is your inlet part defined as rotor? isn't it a slice of the inlet pipe? it's not wrong using 3domains instead of two.

c120613 · April 14, 2010, 08:29

The reason why you have the first part as a rotor part is because in that domain at the hub level you have the part of the nose which has to achieve the radius 0. the nose has to have the same rotational speed as the rotor, for mechanical continuity reasons.

Kind regards

Domenico di Cugno

ghorrocks · April 14, 2010, 18:28

You use rotating frames of reference when the mesh needs to rotate. If the geometry is axially symmetry then you can either choose it to be a rotating frame of reference or a stationary frame of reference. If the wall in the axially symmetric body is not in the frame of reference you can then choose it to be a rotating wall (for a stationary frame of reference) or a counter rotating wall (for a rotating frame of reference).

I think that was a complicated explanation of a simple concept. Hopefully you get the idea.

You should try to minimise the number of GGIs. With the trick mentioned above you should eb able to eliminate one of your GGIs.

But I repeat my comment from my first post. What makes you think what you are doing is wrong? If you use 2 or 3 domains it should still give the same result.

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April 12, 2010, 18:33		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	It should work fine. Why do you suspect it does not work?

April 14, 2010, 07:19		#3
Attesz Senior Member Attesz Join Date: Mar 2009 Location: Munich Posts: 368 Rep Power: 17	why is your inlet part defined as rotor? isn't it a slice of the inlet pipe? it's not wrong using 3domains instead of two.

April 14, 2010, 08:29		#4
c120613 Member Domenico Join Date: Sep 2009 Location: Cranfield Posts: 48 Rep Power: 16	The reason why you have the first part as a rotor part is because in that domain at the hub level you have the part of the nose which has to achieve the radius 0. the nose has to have the same rotational speed as the rotor, for mechanical continuity reasons. Kind regards Domenico di Cugno

April 14, 2010, 18:28		#5
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	You use rotating frames of reference when the mesh needs to rotate. If the geometry is axially symmetry then you can either choose it to be a rotating frame of reference or a stationary frame of reference. If the wall in the axially symmetric body is not in the frame of reference you can then choose it to be a rotating wall (for a stationary frame of reference) or a counter rotating wall (for a rotating frame of reference). I think that was a complicated explanation of a simple concept. Hopefully you get the idea. You should try to minimise the number of GGIs. With the trick mentioned above you should eb able to eliminate one of your GGIs. But I repeat my comment from my first post. What makes you think what you are doing is wrong? If you use 2 or 3 domains it should still give the same result.