le 

3D-SHAPING

PART 2: 3D-SHAPING PROGRAMMING ESTRATEGY

In this PART 2 we continue studying the concept of 3D-shaping, started here: PART 1: Notes on the 3D formation of the leading edge in a paraglider, using ripstop fabric.

This document shows the details and the strategy used in the programming of the module 3D-shaping of Laboratori d'envol. We come back to review the basics, and we propose one method in particular. Now, we just have to move these ideas to a few lines of Fortran code, and integrate the code within the next version of the program LEparagliding. The work is simple. Only it is necessary to define correctly the data, and then the logic becomes trivial. Only the part corresponding to drawing the different parts separated, sorted and marked, will require a detailed and hard work.

To use the program LEparagliding is not necessary to study all these ideas... (!), these are directed only to the researchers of the details and the concepts used inside the program. To use the program you only need to know the meaning of some parameters that we will explain latter in the manual.

The drawings are self explanatory (this is the intention!):

1

2

3

4

5

6

7

8

9

10

pdf version

In relation to the step 7 programming, this is optional. But we can imagine a .DXF/.STL tessellation file that can be visualized with OpenSCAD or FreeCAD and will be very interesting... Crazy Idea, I imagine as possible. And yes...:
tessellation
This page shows a simple method to define a 3D tessellation for the ovalized surfaces. Once calculated the arc that joins the points to the right and left of two contiguous profiles, we only need to split this arc into smaller sections, for example 8. It is necessary to define a local system of coordinates in the own plane of the arc, to make the division in a simple form (for example, calculating the coordinates relative to the center of the arc). And apply the formulas of transformation of coordinates from local to global by translation and rotation:

3D transformation

Now only it is necessary to convert these ideas in Fortran... :)

code
LEP-3.03 testing, starting code for 3D-shaping...

3D
2D intermediate airfoils (white) 2D ovalized airfoils (cyan)

2D
2D intermediate airfoils (white) 2D ovalized airfoils (cyan)

Module 3D-shaping for LEparagliding will be programmed in February-March 2020 according to the plans. This plans will be possible thanks to the support of Scott Roberts from USA (Fluid Wings https://www.fluidwings.com/ ).