Error message in basic Flow Simulation [CFD analysis] NX7 1

[nastynotion]

Hey everyone,

So I'm trying to learn to do some basic CFD analysis using NX 7.0, specifically on internal flow in a test model of a 90 degree angled pipe. My process is as follows:

[ol 1]
[li]I open my part, pipe_test.prt[/li]
[li]Open advanced simulation environment[/li]
[li]Right click part in Simulation navigator and select "New FEM and simulation"[/li]
[li]Use standard parameters, I just change run directory in solve options to "Simulation-solution name" from "current simulation"[/li]
[li]Afterwards I go into the idealized file, and use Wave Geometry Linker, I then open up modelling environment and create the area of the internal pipe with Synchronous modelling and delete face. (I delete everything but internal faces and thus create a model of the flow area)[/li]
[li]I go back into Advanced Simulation environment, and enter the FEM file. I then suppress the body of the pipe, and am left with the body of internal flow area.[/li]
[li]I add a Tetrahedal Mesh (Tet10) with 5mm element size, and add water as material directly through the mesh collector option.[/li]
[li]I then go into the SIM file, and add two flow boundary conditions. Inlet flow (3000mm/s) through one face, and an opening condition through the other face. Illustrated with this picture

[/li]
[li]I right-click solution 1 and hit solve. That's when I get the error messaged which I attached.[/li]
[/ol]

This error basically says two things as far as I can understand

Mesh Error Summary
==================

ERROR

Mesh = 3d_mesh(1)
Mesh has no material applied to it for thermal or flow calculation.
Create a material and apply it to the mesh, the underlying geometry
or the element attributes override.

Which I fail to understand, as I added water as material in the mesh collector option when creating the Tetrehedal Mesh used for the simulation.

I also get this error in the report file:

ERROR

There are no 3D fluid elements or fluid mesh entity in model.
Either create a 3D fluid mesh or fluid mesh entity for flow solution.

Which I fail to comprehend for the same reasons.

Does anyone see where this error message stems from, and what I could do to rectify it?

I'd be happy to add additional informations and/or screenshots. For now I've attached the files I used and the error message in a .rar file.

Thanks in advance, and best regards!

Lars.

 

[BlasMolero]

Dear Lars,
Your mesh "3d_mesh(1)" is located in folder "Solid(2)", that is empty of properties, then the error. Simply "Drag & Drop" "3d_mesh(1)" in folder "Solid(1)" and you are done!.

Using the K-EPSILON turbulence model the CFD analysis solved in 18 iterations (less than 1 minute!!):

You can plot velocity results using posprocessing arrows:

Or animate results using streamlines:

Best regards,
Blas.

~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

IBERISA
48011 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/

 

[nastynotion]

Thank you very much Blas, both for figuring it out and some great illustrations.

I was thinking it had to be something along these lines. I was working with a more complicated model, got the error. Tried to simplify it to just a pipe, and got the same thing!

Once again thank you very much. I look forward to playing around with this feature.

Regards, Lars.

 

[nastynotion]

I'm just bumping this thread for an additional question.

I've played a bit with simulations of fluids in different geometries and conditions, but in a similar setup, is it possible to simulate the dynamic pressure? I can get the static pressure, is there another way around to just taking fluid velocity at different points and calculating it by hand?

Best regards,

Lars.