Airfoil scale rotate and translate

[aafuni]

I am currently working to create a blade model that consists of an airfoil shape that is composed of a leading edge circle, trailing edge circle, connected by 3 tangent arcs on the pressure side and 4 on the suction side. I would like to come up with a way to pattern these sections with a transformation as follows:
Leading edge translates upward,
Foil rotates about the leading edge,
Chord decreases,
and Thickness decreases

Is there a way to do such a thing with a airfoil type shape? The nearest thing I found so far would be to create a polygon that has sides tangent to the airfoil curves, then to use a dimention pattern to create the needed translations. Doing this I still need to redraw each airfoil shape again, tangent to the polygon skeleton, and am running into problems with pro e calculating tangent constraints.

I can do a simple pattern that covers all the needed translations with the foil shape iteslf, but not the changes to the chord and thickness. Additionally the chord and thickness do not change together, ruling out a scaling operation.

Let me know if anyone has any suggestions.

 

[dgallup]

Sounds like you need to do either a swept blend or a variable section sweep. I personally have better luck with swept blends, you can draw the section at multiple points and can rotate each section in all 3 axis. I'm sure the VSS guys will disagree & find ways to use multiple graph features, etc. to control it.

 

[mjcole]

Id love to help you out with this but for the greater Eng-Tips group who haven't worked with airfoil data could you give a better description of the parameters and specifications such as Leading Edge and Trailing edge thickness and other specifications. I used to work at a Company that did some Unigraphics work for GE Aircraft Engines and have seen drawings like you are asking about. Models I have made used points files with multiple 3d loops that splines were created between but you are saying these are actually combinations of multiple arcs. I'm not about to post GE drawings and assume you can't for the same reason post yours but a sample of the drawing you are working on would help. I assume you can draw the basic Arcs as Circles and draw a Chord length or location from end where thickness is measured from. I think a good Idea would be to use a table driven pattern and include an offset datum distance along airfoil center axis and specify something like the following

SecD Section Distance grouped offset datum
(L,M,T)E (Leading,Max,Trailing) Edge Thick
CH Chord Length

idx# SecD LE MT TE CH
idx1 0.00 .12 .18 .1 3.0
idx2 .80 .15 .25 .1 4.0
idx3 1.5 .15 .25 .1 3.7
idx4 2.7 .18 .30 .1 3.2
idx5 4.3 .12 .18 .1 2.5

When you do the pattern table you can then use the select option in Swept Blend to create feature or can sketch an Origin Path and dimension the section locations from a baseline and sketch your x-sections during feature creation.

Another option would be to use Feature Cope and Paste Special Advanced Reference Configuration and pick different sketch plane and modify your section dimensions to match the desired airfoil data. With the Table pattern you can select multiple dimensions for table using CTRL key and edit data for each instance id idx1, idx2 etc in first Column of table

I am a bit of a VSS fan but in this situation I believe the Swept Blend is the best and easiest option No equations or complex guide curves.

Michael