ANSYS 12.1 Automatic CFD meshing on complex passenger cabin geometry

[Raashy]

Are these mesh generation processes suitable for determining drag coefficients? Can it create adequate boundary layer meshes?

[Ultravis66]

I am sorry to say that this new software has let me down. I tried to grow an inflation a projectile that travels at M 2.5. Unfortunately the mesh generation tool that is automated constantly fails after having to wait 1 hour for it to generate @ around 2.5 million elements and my geometry is not even complicated. Workbench 12.1 meshing does not compare to the power and robustness that Gambit/T-grid had. With tgrid I could generate meshes 5 times faster on a processor 5 years older.

[ansysinc]

@Ultravis66 You should contact technical support with your problem. The inflation tool in the Workbench meshing is Tgrid and the size function is Gambit. There is no reason for it to fail. There may be something wrong with your process and set up. After you have contacted support let everyone here know if your problem is solved.

[Ultravis66]

@ansysinc

I know that 12.1 has tgrid code embedded in it. The problem here is time. If I go to generate a mesh in t-grid I can generate a 5 mil element mesh in 10 min. In 12.1 It takes an hour. Also, the program allows me to preview my inflation before I generate. It should give me an error right there before I try to generate a mesh not an hour after I have been waiting for it to mesh my domain. It is simply unrealistic in terms of time.

[ansysinc]

@Ultravis66 Sounds like you are running out of RAM. This is exactly what support is for. Give them a call and they will make suggestions on how to continue.

[Ultravis66]

@ansysinc

Today at work I put your theory to the test. I have the new workbench 12.1 and my colleague using the old gambit/t-grid (he has not made the upgrade to 12.1). We both have I7 p.c's with 12 gigs of ram. He was able to generate a mesh in 10 min with a first sell height of 8.5e-3mm. I tried to generate the same mesh and took 20 min and it failed to generate the inflation layer. But, I had to wait 20 min for it to tell me that. At a whopping $70,000 cost I expect only the best!

[ansysinc]

@Ultravis66 As I said before this is what your technical support is for. Call them and they can help you. The PRISM mesher in Workbench 12.1 is very good, there has to be something wrong with your set up.

[Brad1711]

Nice video. I'm an Aero Eng undergrad but haven't taken any practical CFD courses. I have taken two courses on CATIA so I've been trying to teach myself how to get from a .catpart to getting results in Fluent.