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Trying many avenues to perform solids subtraction for vanes & flowpath

Trying many avenues to perform solids subtraction for vanes & flowpath

Trying many avenues to perform solids subtraction for vanes & flowpath

(OP)
On UG/NX 7.5 which we lack any decent manual for (I checked all our local libraries and amazon for good third party guides; the former has nothing and latter all cover NX v2 or 3 or 4....).

What I am trying to do is place vanes from lofted x-section data points in a gas flow channel which is also for similar data. Have tried several approaches to get a clean part for our CFD folks but seem to get tripped up. (Part is attached in NX7.5 format tarballed).

Approach #1: Generate 2 revolved solids from two closed curves and subtract these from the vane (before grouping it and rotating to 22 instances). The problem is there seems to be no easy way to knock of the excess "sprue" inside and outside the gas flow path channel walls. Tried to knock off the outer sprue with a cylinder that is extruded up as a subtract tool, but the boolen does not allow it after grouping and instancing.

Approach #2: Generate 3 solids from three closed curves, one a slightly shifted in (0.01in) set of curves for intersecting with the vane. This works well, but I cannot seem to make the curves coincident and still revolve. Move them in about 0.01in, the minimum to get this approach to work and the final vane has little gaps between the ends and the flow channel walls, which I have no idea how to close.

Approach #3: Tried to copy by using revolving the two complex splines to a new datum 90 deg offset from the main gas flow path parts sketch, but can only seem to revolve them in the sketch plane.

Anyone have an idea on how to proceed on any/or all of these three spproaches (or another, better one)?
 

RE: Trying many avenues to perform solids subtraction for vanes & flowpath

(OP)
Yes, that looks exactly what I need. What were the key steps needed. I have been fighting with it most of a day to get the solids trimmed? Thank you for your time.

Oliver
 

RE: Trying many avenues to perform solids subtraction for vanes & flowpath

Just look that Part Navigator and you will see the steps I took.

To help you understand what I did, I first deleted everything past Revolve(23).  Then instead of attempting to do a Subtract I performed a pair of 'Replace Face' operations which gave me a single 'clean' Blade.  I then used 'Instance Geometry' to get 21 copies and then just performed a pair of 'Union' operations to get the final model.  If you use Feature Replay you can see exactly what I did (as well as your operations).

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.com/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Trying many avenues to perform solids subtraction for vanes & flowpath

(OP)
Really appreciate the two responses, here's another one that I was hoping to get a suggestion on how to proceed, this is the matching rotor for the vane assembly previously shown in the thread, probably done in the same very inefficient and inelegant manner as I was doing the stator assembly. A couple of questions: 1) Is there a more efficient way to get the circular shrouded tip profile one the blades much like Mr. Baker with the stater vanes using the redefine face command used. I had done the circularization of the blade tip profiles using a Boolean subtraction of a cylindrical shell as the shroud tool part.....

2) Is there best way (certain command/set thereof) to go about filleting the roots of the blades to around 0.25" each. I've tried some of the functions but not sure if slight gaps are plaguing the process.

I've attached the NX7.5 file for the matching rotor. I actually feel I got somewhere getting the blade profiles in, but getting them onto their hub/rotor and shroud hardware has been challenging. Thanks again for the helpful responses.

Oliver
 

RE: Trying many avenues to perform solids subtraction for vanes & flowpath

OK, here's my version of your second part.  Again, the approach I used was very similar to the first part only this time I used a Trim Solid instead of a Replace Face, which gives basically the same result.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.com/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

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