topic Re: hi guys help me plz in CFD Forum

simulate propeller in ocean

dbsxorn96 — Wed, 25 May 2022 00:53:54 GMT

hi guys i want to simulate propeller in ocean

so i need 3d propeller. so i make that 3d propeller in cad and i convert to iges.

but i cant give motion to propeller so i cant simulate.

what is the problem i really dont know the reason help me plz!

the file is dwg cuz i cant add iges file sorry about that...

Re: hi guys help me plz

karol.suchon — Mon, 23 May 2022 07:38:22 GMT

Hello,

Please pack the CFZ file into a zip file and attach it again.

best regards,

Karol

Re: hi guys help me plz

dbsxorn96 — Tue, 24 May 2022 07:33:11 GMT

thanks the reply carol!

this is full file in cfd!

i really thanks to u!

Re: hi guys help me plz

karol.suchon — Tue, 24 May 2022 09:13:02 GMT

Hello,

in the file, it looks like you applied the movement but you do not apply the centre of the rotation. So the movement will be rather weird.

There is also one additional issue, in your original geometry the element is far from the coordinates system, and the software could have problems with properly computing the centre of the rotation. The accuracy of the operation will be low. In that case, open a model in CAD software and move the propeller to the centre of the coordinates system.

You also should increase the outer volume to compute the flow properly and create some refinements region. In another case even if you run the simulation the results will be far from true.

Re: hi guys help me plz

dbsxorn96 — Thu, 26 May 2022 11:37:40 GMT

thank u carol! i resolved that problem! so i can simulation in cfd.

haha i really thanks to that. but now i have the only problem.

if u don't mind can i ask about that problem?

that problem is the boundary condition. i only add pressure 98000pa.

but what i want to simulate that is in generator. if u don't mind then see that attach file

Re: simulate propeller in ocean

karol.suchon — Thu, 26 May 2022 12:07:48 GMT

No problem 🙂
First, you need to create the geometry, I think that it is not a necessity to apply more volume than the hole in the concrete body. Something similar to the case below.

If that is the turbine we should apply the conditions which allow us to absorb the energy from the fluid, so probably you will need to apply the pressure difference on both sides or inlet flow and pressure on the outlet. The turbine is close to the water level but I think that we could ignore the potential waving on the surface generated by the turbine.
By the way, computing the turbine is a rather complicated operation and requires a good mesh creation which the motion model is not able to achieve. So will propose using the rotating region simulation.

Best regards,
Karol