GE-90 Pylon Model

[CPAERO]

So Im helping a friend with his masters thesis and i need to create a similar engine pylon to the one used with the GE-90 on the 777 (for later CFD). I have created something i am reasonably satisfied with but i have a few problems i need to work out. I am new to ISDX and have been experimenting with it while creating this part. So here are some pictures of what im dealing with.As you can see Im having some issues with the styled surface. I know a big part of this kind of modeling is making sure reflections are continuous and i havent really achieved that very well.

Any suggestions on how to get rid of the ugly edge at the top of the green surface?

Surface edit within Style seems like it would work but i am hesitant to edit the surface freely. Thanks for the help.

Eric

 

[design-engine]

upload the model.... chances are that there are other modeling techniques available that will facilitate the continuity issues you may be having.
Edited by: design-engine

 

[CPAERO]

Alright so here's the part file, however I use the Student Version of ProE (wf4), I also included a .stp and a .igs if thats better for anyone.


Please keep in mind I'm starting out with this stuff--My tactics are pretty primitive.



2009-09-24_164825_post_upload.prt.zip

 

[bimbo666]

Hi CPAERO,


I know well the turbo-fan enginehigh-bypassfamily that was developed byGeneral Electric, and you plan to do CFD right?, but at wich stages, fan or compressor ones, supposed you're trying to model the blade surfaces for the turbofan, to define the suction and pressure surface, I took a look at the igs model you posted, and you're right the most robust surface the better CFD results you get!


Where did you get the airfoil sections data at first?.





This imagen was a dummy turbofan model in proe by myself





Regards


Pablo Ulloa

 

[magneplanar]

have you looked at the pylon as it is on an actual airplane?

i think this might help: image

but seriously...

the area you are modeling is not actually a part of the engine , the engine tucks in underneath, like here: image

If you notice, the lower section aft of the nozzle flares upward a bit to be out of the thrust stream.
The pylon itself is like a V, widest at the wing root and then the flared section to transition to the engine.

the cowlings closed: image or this: image

cheers,

M



Edited by: magneplanar

 

[CPAERO]

Hello Pablo & M,

Thanks for your responses.
Regarding Pablo's response: My friends masters thesis focuses on engine/pylon chordwise & spanwise placement (also involving CCW wings & a blended wing-body). As far as I know he is not planning on involving the internals of the engine--maybe his downfall. Ill get some more info about this on monday.

The Turbofan model of yours is pretty cool. How did u model the blades? VSS? Boundary Blend? ISDX?
Regarding M's question: Although my model may not convey it, i have been studying those pictures for a couple of weeks now...barring the lego one. Thanks for noticing the flare of the pylon aft of the nozzle exit--Ill make the adjustment.

Any idea of the pylon geometry inside the fan nacelle aft of the fan exit? (hidden in most pictures by the fan nacelle).

And the final question still remains for all the experienced ISDX users: Any idea on how to get rid of the ugly edge at the top of the green surface? The grey surface is an ISDX surface bound by 4 COS's and guided by Free curves with ends that are constrained to be tangent to surface.

Thanks for the advice.

Eric

 

[magneplanar]

cpaero,

there are a few sites that show the underlying structure if you search a bit, such as:

link

Basically the upper structure above the fan is just to cover the link arm, which connects the engine to the wing root, and provide a path for fuel and electrical connections. The area below the wing covers another arm and holds the accumulators and other components.

to answer your ISDX question, i think you are trying to do to much with that one surface set. I suggest you split that area into at least two regions, like on the real pylon, and build in more curve structure to hold your surfaces.

cheers,

M