SimScale CAD file question

Project Support
1

I am currently working on the CAD file to test the performance of the fan in SimScale. Is it necessary to design the blades’ attachment to the motor’s shaft how it’s planned for the prototype in order to conduct the simulation in SimScale? Or is it sufficient to simply assemble the motor and blades, and marking the blades as movable and the motor as stationary in SimScale? Is there such a function?

2

Hello Alena, thanks for posting your question here in the Forum.

When preparing the rotating zones in the CAD mode, you can choose to cover any parts you prefer. A standard rotating zone would be a cylinder, however you can choose to create a rotating for example like a bagel shape to exclude non-rotating parts.

In case you already have the CAD model in your projects, could you please share a link? It will be a lot easier to understand your application and purpose.

Thanks!
Kaan

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3

Hello Kaan,

I’m working with Alena on the fan performance project using her CAD files I imported into SimScale. I keep running into a problem when assigning material type to a body, as no solid materials are available, only gasses and fluids. Is there a way to fix this?

4

Hi there,
if it is a flow simulation, then you only assign fluid materials. If it is heat analysis or structural analysis, you would have the option of applying solid materials.
Best,
Bhagyashree

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5

Could it be that you design the fan using surface? If yes, depending on your CAD software, there should be option to make a solid out of surface. Try it.

7

What is surface? Is that a CAD program? I’m sorry, but I still have no idea what to do. I need the various pieces of the fan to be solid for the simulation to work, but that’s not possible in the Incompressible format. This seems like an impossible issue to solve

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I mean it as one of the type for geometries in CAD. For example, if you’re designing the CAD model using Generative Shape Design module in CATIA, you will get Surface Geometry instead of Solid Geometry. Which CAD software are you using for the fan design?

Are you trying to simulate the flow of air through the fan blades or stresses and strains of the fan components?

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I’m trying to simulate the flow of air through the fan blades. The fan blades and walls of the fan need to be a solid for the simulation to work correctly, so the air flows as it should in a real fan, if I’m thinking about this correctly. Without any solids, the air just travels anywhere. For the fan design, we’re using Siemens NX CAD and FreeCAD

10

Hi @william_miller!

Since you are just simulating the flow of air through the blades, then it sounds like you are just trying to run a flow simulation. In a pure flow simulation, the material properties of the fan do not matter. You are treating the fan as a (probably rotating) rigid body in the flow domain. You do however need to specify the properties of the fluid (in this case air) in the flow domain as you mentioned.

As @bbhagat98 mentioned, in a heat transfer or structural analysis simulation, you would need to assign material properties to the solid materials to solve the heat transfer or stress within them. However, it is not necessary in the pure flow simulation.

Hopefully this clears things up a little bit!

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11

Thanks for the response, I think I was doing that earlier, I made a flow region of the fan when I edited the geometry in CAD mode, but I don’t think it worked properly. The air velocity readings I got were near or at 0 m/s, which can’t be correct as I input the air velocity at 10 m/s (as an example) in the velocity inlet, and I’d assume that it would be close to that near the velocity outlet. The device itself is supposed to intake air from one end and then go out another being blown by an interior fan, and this is all in a microgravity setting. I’m not exactly sure why the air flow isn’t functioning as it should

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I’m not quite sure what’s going on then. Would it be possible for you to share a link to your project? It would make it easier for someone to figure it out.

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Sure. I think I’ve attached it right. The Fan 1 geometry is the full model, the Copy of Fan 1 is the flow region created in the CAD mode.