Hello All, I'm relatively new to the field of CFD and I'm starting working on Masters/PhD research at UCSD. I'll be working on the aerodynamic design of a UAV that we're building here. I'm wondering what commercially available CFD codes are the most appropriate to this sort of analysis. Initially I'll only be concerned with the static structural case of airflow over the design, which will be a blended wing design (so the easy to use airfoil design software can't be used). I'll then move on to aeroelastic interaction, which I'm sure will be much harder and possibly require some original thought and code.

I've been looking hard at STAR-Works because it seems as though it integrates nicely with SolidWorks - the CAD package we've used to model the design. STAR-CCM+ is also an option, if the SolidWorks interaction isn't as nice as it sounds.

I've also looked at CFX and FLUENT and they look to be about the same (as far as I can tell).

Since our design is modeled in SolidWorks, I think I'll be forced to run Windows, but I'd rather run Linux.

Any input is appreciated. Thanks!

Considering what you are trying to do, I would use either Gridgen or GridTool/VGRID for gridding. The latter can be obtained for free. Both take IGES-input, although some entities may not be read in properly.

For solver, take a look at Cobalt. I've been happy with its performance for MAVs and other aero-problems as well. All these have been for a fixed geometry.

Just my two cents, not advertisement....

-- Jarmo

I guess the first thing I would look at is FloWorks PE since it is sold by SolidWorks and integrates directly into SolidWorks. It does not run on Linux but has the advantage of working directly with the SW geometry making iterative analysis much easier. Your University probably already has an agreement in place for you to check FloWorks out.

Best regards, Mike

CFX is the only commercial code with a laminar-turbulent transition model and your blended wing body case would a very interesting test case for transtition (smooth geometry, low Reynolds number). Also CFX had very good predictions of lift, drag and pitching moments at the last AIAA drag prediction workshop. If anyone is interested, email me (robin.langtry@ansys.com) and I can forward some papers on these two topics.

Robin Langtry

Hi Robin,

Just a minor correction to your post..."CFX is the only commercial code with a laminar-turbulent transition model". EFD.V5 (for Catia V5), EFD.Lab and FloWorks have a laminar-turbulent transition model.

Thanks, Mike

Has there been a paper written on the model and has it been validated for more than just one test case (i.e. predicting the drag crisis of a cylinder)? My feeling is that you can't really claim you have a transition model unless you can show that it can predict the combined effect of freestream turbulence intensity, pressure gradient and separation on transition for a variety of different test cases/flow conditions.

R.

Yes, there are academic and commercial validations. Perhaps you should take some time to learn a bit more about the codes you slight when you claim CFX has the only laminar turbulent transition model.

Sorry to everyone else, I didn't mean to hijack this thread but Robin's statements couldn't go unchallenged, imho.

Wasn't meant as a slight, I've just never seen any papers published on this transition model before, as a result I've never heard of it. My only point is that transition modelling is a tough field and to convince people you have something viable you have to demonstrate in an open forum it works. This is why we published two papers on our transition model at the IGTI 2004 in Vienna (papers GT2004-53452 and 53454). All I was asking is if there has been a similar validation performed on your model and are the results being openly disseminated. If so, fine what are the references.