Spiral Paths in Flow Volume. Tesla Turbine

cameronrtuttle · February 9, 2022, 12:50am

Hello Everyone. I’m trying to get my particle trace to enter the spiral paths in my flow volume. It either won’t show the particle paths, or it doesn’t enter the spiral path in the simulation at all.

(Flow Sim Results. Particle trace on both the exhaust and inlet. Missing particle trace in spiral paths):

I have designed a modified Tesla Turbine in which the disks have Archimedean spiral engravings leading from the outer permitter of the disks into the central exhaust holes. The idea here is that by forcing the air to take a longer path, the air will cover a greater surface area and produce more drag from the boundary layer effect.

(Example of 12 Disks Stacked. 10 degree rotation between each disk):

Here is the casing with the disk stack inside.

Here is a cross section.

I use the internal volume flow tool in the SimScale cad editor and I get a good flow volume. All of the empty spaces are connected and there is a complete path from the inlet to the outlet.

Here are my Mesh Settings.

Here are my Simulation Settings.

As I said at the top, I just want to show the path the fluid takes from inlet to outlet.

There is no Rotating Zone in this simulation.

Could it be a problem with my mesh? I am only a hobbyist so I’m not that experienced.
The purpose of this simulation is only to produce a cool visual. It should look like a tornado, with air entering the perimeter of the disks, spiraling inward, and converging in the central exhaust. The specific conditions of the simulation don’t really matter.

Any advice would be appreciated. Thanks!

Project Here:

SBlock · February 9, 2022, 7:30am

Hi cameronrtuttle.
interesting Simulation project you have here. the issue that you are facing is that SimScale cuts off the particle traces after a specific “length” (Life time) this is a feature to prevent an endless particle trace if going in circles.

One thing you can do you can add a particle trace at the end of the finished one, from what I can see in the cutting planes the fluid volume looks fine.

But would suggest you further refine the mesh.

You want to have at least 3 hex core cells between the surfaces of these two parts.
My suggestion is to use surface refinments. You can see how to use them here.

Best regards Sebastian

cameronrtuttle · February 9, 2022, 8:03am

That’s good to know, thanks. I might try making a different version that doesn’t let the particles go in circles too. Or I might have a look at the vector tool on a cutting plane as I haven’t tried that feature yet. Either way thanks again for your help I’ll continue to refine my project and hopefully get the visualizations I’m looking for.