topic Re: Help with Centrifugal fan and rotating region in CFD Forum

Help with Centrifugal fan and rotating region

Anonymous — Fri, 20 Mar 2020 19:06:52 GMT

Hey,

Can anyone please help me understand why the solver is failing and also provide any steps to make this study more accurate?

Any help would be appreciated.

Thanks

Re: Help with Centrifugal fan and rotating region

KubliJ — Fri, 20 Mar 2020 20:52:43 GMT

Hi @Anonymous

It looks like the rotating region got switched with an air volume. It is assigned to a volume (Volume 35) that encloses an air volume (Volume 39) that encloses the impellers. The air volume that encloses the impellers (Volume 39) needs to be assigned as the rotating region and Volume 35 needs to be assigned as air.

Thanks,

James

Re: Help with Centrifugal fan and rotating region

Anonymous — Mon, 23 Mar 2020 13:37:59 GMT

I thought that was what was wrong too and I made the Rotating Region a solid piece and inserted the fan into it. This got rid of the CFD created volume and I was able to set up everything. It still failed as the solver started.

Re: Help with Centrifugal fan and rotating region

Anonymous — Mon, 23 Mar 2020 14:38:51 GMT

Attached wrong file

Re: Help with Centrifugal fan and rotating region

Anonymous — Mon, 23 Mar 2020 16:09:01 GMT

Does the rotating region need to be a solid cylinder or a hollow one? @frederic.gaillard.7

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Mon, 23 Mar 2020 16:52:29 GMT

Solid cylinder surrounded by a fluid material

Re: Help with Centrifugal fan and rotating region

Anonymous — Mon, 23 Mar 2020 18:16:50 GMT

@frederic.gaillard.7 Please help me understand why this failed

Re: Help with Centrifugal fan and rotating region

KubliJ — Mon, 23 Mar 2020 20:32:41 GMT

Hi @Anonymous

Take a look at this model. It should run without issue.

Thanks,

James

Re: Help with Centrifugal fan and rotating region

Anonymous — Wed, 25 Mar 2020 13:55:26 GMT

Hi @KubliJ ,

For some reason, I am unable to get any results from your version. Similarly, I tried editing my CAD model per your changes and was unable to get any results even though I left my computer running overnight.

I'd appreciate any help you can provide. @frederic.gaillard.7

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Wed, 25 Mar 2020 16:45:54 GMT

Hello Aditya,

You use a more recent version than mine, i can not open it. If you want me to have a look please share your step file.

Thx

Fred

Re: Help with Centrifugal fan and rotating region

Anonymous — Wed, 25 Mar 2020 16:50:05 GMT

Hi @frederic.gaillard.7 ,

No problem, attached Parasolid and STEP file here. Thank you very much!!

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Wed, 25 Mar 2020 20:18:14 GMT

Hello Aditya,

Your fluid volume who surround your rotating region is empty :

This region must be filled the same as your intlet and your outlet.

Hope it helps
fred

Re: Help with Centrifugal fan and rotating region

Anonymous — Thu, 26 Mar 2020 15:20:29 GMT

Thanks @frederic.gaillard.7 ,

Was able to see some results.

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Thu, 26 Mar 2020 16:04:02 GMT

Hello Aditya,

No problem, you can send me your new step file if you want i will run it on my end with the good pratice of the turbomachinery.

Fred

Re: Help with Centrifugal fan and rotating region

Anonymous — Thu, 26 Mar 2020 19:04:26 GMT

Hey @frederic.gaillard.7 ,

Thank you so much, I really appreciate it. Attached in this post.

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Thu, 26 Mar 2020 20:07:44 GMT

Hello.

You reproduce the same error.

Intlet and outlet must be complete solid, not hollow prism or cylinder like you have.

furthermore you have a lot of small ''air volume'' around your rotating region, make sure you only have three air region

intlet
impeller housing
outlet

Fred

Re: Help with Centrifugal fan and rotating region

Anonymous — Thu, 26 Mar 2020 20:19:09 GMT

Is this better?

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Thu, 26 Mar 2020 20:37:25 GMT

Yes, but try to model the housing in one piece

Re: Help with Centrifugal fan and rotating region

frederic.gaillard.7 — Thu, 26 Mar 2020 22:03:39 GMT

Hello Aditya,

Your making progress, all the the computational domain is filled by a fluid which means all the pressure and the velocity vectorial field could be resolve in this domain, well done !

However, You still have work to do on your impeller.

First thing to do is to close your blade, right now you have air inside your blade, see by yourself :

you almost there !
Fred

Re: Help with Centrifugal fan and rotating region

Anonymous — Fri, 27 Mar 2020 14:57:12 GMT

Ok @frederic.gaillard.7 ,

Made the Blades a solid piece.