Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Close

Inventor General

- Autodesk Community
- >
- Inventor
- >
- Inventor General
- >
- Equation curves

Topic Options

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic to the Top
- Bookmark
- Subscribe
- Printer Friendly Page

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Email to a Friend
- Report Inappropriate Content

558 Views, 3 Replies

01-29-2013 10:18 AM

Hi

I found tutorial for symmetrical equation curve for NACA Airfouil in Inventor 2013. http://www.youtube.com/watch?v=zKSBe9hImTE

I need to create assymentric airfoil. I am wondering if there is a possibility to put equation in Inventor which looks like the one I attached in doc file.

If it is not possible that's OK as I can use coordinate generator in the internet and put coordinates into inventor so I can draw it but It would be nice to put set of the equations rather than manually put 100 points.

I know that those equations are more complicated and I don't know how to start with them in Inventor

Solved! Go to Solution.

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Email to a Friend
- Report Inappropriate Content

01-29-2013 11:51 PM in reply to:
PiotrekL1

I'm not in front of Inventor right now, so can't check the syntax for the equation curve editor - but I would say "yes", this is possible. For now, I'd just recommend inserting points from Excel. Inventor will draw a spline through the imported points for you - it's like the poor-mans Equation curve editor! Have a look at the expanded tool-tip for the format of the Excel sheet. (It's on the Sketch > Insert panel.)

Peter

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Email to a Friend
- Report Inappropriate Content

01-30-2013 12:43 AM in reply to:
pcrawley

Hi

I will follow your advise. I will generate coordinates in the NACA tool and put then through MS Excel into inventor

Thank you very much

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Email to a Friend
- Report Inappropriate Content

05-13-2013 06:43 PM in reply to:
PiotrekL1

Been working on this to...

My end goal is to have an assembly with n number of NACA 4 digit (and others) profiles. This will allow the user to quickly develop a surface model to export to a CFD program.

Parameters to control (between each section):

- Sweep
- sweep
- dihedral angle
- span
- twist

Parameters to control (For each section):

- NACA Type
- NACA Parameters
- Camber length

**Step 1: Developing NACA 4 digit profiles**

Approach 1: Sketch Equation Curve

Following equitation on http://en.wikipedia.org/wiki/NACA_airfoil, I was successfully able to develop the mean camber line (with two different equation curves). While trying to add the equations for the top and bottom of the profile, I ran into many issues most of which resolved after time, although not all.

Problem(s):

- The parametric equations are not fixed in space (i.e.. you can drag them around) and I have not been able to successfully relate all 6 curves, trailing edge, and leading edge (approx. as a circle).
- The beginning of the forward curves approach div by zero and are as such not useful.
- Very cumbersome, extremely hard to use and error prone.

Approach 2: Thickness Circles + mean camber line = Spline (kinda)

Using my sucsessful mean camber line, I added 10 circles along the mean camber line and demendsioned their linear poisiton along the mean cambber line using the x_u parametric equations, and their heigth demension from the x-axis using the y_u parametric equations.

Problem(s):

- After passing the max mean camber position, things started going badly. It turns out that inventor was not parsing the equations correctly. This could be a program or user error, the jury is out on that one. See post here: http://forums.autodesk.com/t5/Autodesk-Inventor/De
mension-Copy-Parse-Error/m-p/3920847 - Cumbersome (seeing a trend here). While I could type all the equation in the tiny window and get it work corretly, I feel I have better things to do in my life, and there is probably a better approach.

Propossed Approach 1: iRule/iLogic/API

The title is garbled because I don't know enough about each of those, but my preliminary research shows this may be the correct approach. The plan is to create a set of point using the parametric equations to define a spline.

If anyone has any questions/comments/advise please let me know.

Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register

Announcements

We’re looking at a few different ways to improve the “All Forums” landing page and need your feedback! If interested, please take a few minutes to fill out the following Usability Study. Thank you for your time!

Start with some of our most frequented solutions to get help installing your software.

Upgrading to a 2015 product? Make sure to check these out 1st!

Created by the community for the community, Autodesk Exchange Apps for Autodesk Inventor helps you achieve greater speed, accuracy, and automation from concept to manufacturing.

- Privacy | Legal Notices & Trademarks | Report Noncompliance | Site map | © Copyright 2014 Autodesk Inc. All rights reserved

Except where otherwise noted, this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Please see the Autodesk Creative Commons FAQ for more information.