SimScale CAE Forum

Cycloidal propeller

Hello, to my internship I have to simulate a cycloidal propeller ( Operation in this video: https://www.youtube.com/watch?v=HyJHX6MZOWg ).

I have to set up a Rotating zone in a Rotating zone, the probleme is that a center of rotation must be declared but in that case, this center of rotation will move. Do you know if it is possible to set up?

A second problem, I already do a cycloidal propeller but without pitch control and I have some issues, I don’t know how to do a rotating mesh (in fact I’m not sur that a cylinder creates with “topology entity set” around blades will rotate too). For now, I just did a big “Surface refinment” for blades.

Do you know if I can do a rotating Mesh?

I don’t if it’s related to the Mesh but my simulations with just a “big” surface refinment are aborted with this message:
“mpirun noticed that process rank 3 with on node 61a76d21c8c6 exited on signal 15 (Terminated)”
Do you know what that mean? I googled it but I found nothing with “signal 15”, just with others numbers.

Thank you (sorry for bad english)
Adrien

Hi @asimon,

Thanks for posting your question and welcome to simscale :slight_smile: I think you are on the right track by looking at the propeller project from @gholami.

If you ignore the pitch control, and use a rotating mesh (with AMI) this should work. Although keep in mind that AMI is more computationally expensive than MRF.

To move ahead with this, can you share your project link publically so that we can take a look at your current settings?

Very interesting project btw!

Cheers,
Anna

Thanks for this answer, first mistake found: my boundary conditions on blades were a non mobile wall.

You can see my project here:
https://www.simscale.com/workbench/?pid=4812941713060328553#tab_0-0
(some of names are in french, sorry for that. in English pale=blade)

Cheers

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Hi @asimon,

To update you on where we are - I’ve ran the simulation and it crashed. I suspect it’s due to the current quality of the mesh. You can see that the cells on the edges of the MRF region are not smooth.

So I took your geometry and filleted the edges of the MRF cylinder and will see if this helps us get a better mesh quality.

Best,
Anna

Hi @asimon,

I’ve made some more progress on this (https://www.simscale.com/projects/AnnaFless/voith_2/). I ran it as an AMI, up to .09 seconds before I exceeded the maximum runtime which I set to 200000 seconds. By increasing this runtime, you should be able to capture up to .25 seconds for a transient run.

Cheers,
Anna

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Hi

Thanks a lot, I will look at it, sorry for my late answer, I was working on something else last weeks

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Hi @AnnaFless
I ran your propeller, it is still runnig in fact, and it looks to work (Force plot is ugly but I think it is normal on the first rotation of the propeler).

I have another question about the pitch control, each blade has to rotate during the rotation, but I have to put “Rotation Center” on “Rotating Zone” and in this case this rotation center moves. It looks like the mesh moves with the AMI simulation, if I put as a “Rotation center” it position at t=0s, do you know if this rotation center will move (as the mesh)?

Cheers
Adrien

Hi @asimon,

Regarding the pitch control, rotation of the blade is not currently possible :slight_frown: We only support fixed center and axis of rotation.

We have a section in our forum for Feature Requests (https://www.simscale.com/forum/c/feedback/feature-requests) if you’d like to request this functionality for future versions of SimScale.

The current setup, with AMI mesh rotation is the best we can do for now - I hope that’s ok for your internship project.

All the best,
Anna

Hi @AnnaFless

I can’t blame you for that, your website allowed me to have a first CFD result whereas my company didn’t want to buy a CFD software, so thanks a lot for that and also for your help. By the way I’m sorry, it looks like I exceeded the limit with this simulation.

For my internship, don’t worry, in fact I have to make an algorithme with Matlab to determine propeller performance, CFD was just a way to check my results but I found experimental results few weeks ago so I don’t even need CFD (I continued this study because I really liked to do it).

For the request, I will do it even if I don’t need it because I think it can be a good idea for this software, especially since Darrieus wind turbine with pitch controle come back to some offshore wind turbine project.

Thanks a lot again, to your company and especially to you for your help

Adrien