[scottneh]

Hello, I'm curious if anyone here is using NX for CFD? I have a license of it though my university and I'm trying to simulate fluid flow around a wing and I am stuck on the simulation set up. I can't find any examples or instruction on how to use the CFD functions in the Advanced Simulation package with NX. UGS offers training but its only in Ohio and Michigan and I'm in California. there are no books, online tutorials, articles, examples or anything else for that matter regarding CFD in NX. I have bought a couple of books promising to talk about this material but when they come in all they have is FEA and when I call the author/publisher they say they are planning on putting it in the book but it won't be out for several months. Even the NX help files are really vague.

This might seem like kind of a rant but...how can a compay produce a product and not have any resources available explaining how to use it?

Here is my problem in a nutshell...I have the wing modeled, I have a solid body (rectangle) modeled and meshed as the fluid. I have all the approriate properties set. However, when I try to run the simulation I get errors saying that the wing can't intersect the fluid, or the mesh isn't correct or surfaces are selected, and on and on.

If anyone knows of a tutorial that I could use, whether its basic or advanced, even if I have to pay for it, I would really appreciate hearing about it and where the link is.

Thanks
Scott

[Lysistrata]

Originally Posted by scottneh

This might seem like kind of a rant but...how can a compay produce a product and not have any resources available explaining how to use it?

They got your University to pay for it. Why should they produce something extra for a bunch of idiots who fall for an old capitalist trick?

[scottneh]

This is uncharacteristic of Siemens. Most of their help files and examples are quite good and they supply excellent examples with Femap.

[genkukov]

There are tutorials for setting it up, but it is relatively basic. It isn't too hard, but it is still nice to have some direction concerning it.

I'd recommend the fluid automesher to develop the fluid meshes. The technique is as follows:

1. Create Basic model of wing
2. Boolean out the wing out of a fluid solid
3. Create both a FEM and SIM of the model.
4. At the simulation level, apply a "Fluid Domain" boundary condition to the solid
5. Set your typical inflow and outflow conditions (Inflow and Opening)
6. Apply a boundary surface to the wing.
7. Set your solution options (i.e. output choices, etc.)and hit run. (probably check high speed flow if you're running the advanced flow).
8. Should be able to post-process.

I've found that works out pretty well, even though the mesh controls are somewhat limited and it doesn't generate the best meshes. It will at least get decent lift results up to about Mach 0.6. Drag may be another story (this was based off testing an NACA 4412 airfoil against experimental). The tool is more geared for internal flows. The turbulence models and such (I believe the options are mixed length, k-e, and SST).

Hope this helps.

-Andrew

(P.S. The documentation for the NX Flow Product is somewhat limited. It is actually an add-on integration by a company known as Maya TMG. They create an excellent thermal product and a decent mid-level CFD product. If you have access to the learn-at-siemens or CAST material, you may be able to access the tutorials)