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gnuLAB3 "Barretina 2"
Rando-light paraglider



1. BASICS
2. THE gnuLAB3 AIRFOIL
3. THE PRE-PROCESOR
4. INPUT FILE FOR LEPARAGLIDING 2.0

5. OUTPUT FILE, LINES LIST, AND PLANS
6. SELECTION OF MATERIALS

1. BASICS

A
new dream begins... The name is gnuLAB3. A small gnuLAB2 evolution. Possibly same planform, and the same or close aspect ratio. Cells number increased to 31 or 33, is sufficient. A new gnu airfoil, faster and more stable... A behaviora objective EN-A. It is difficult to meet the EN-A requirements..., but we have to be as close as possible. Lower surface, as light as possible... Nylon rods in the leading edge work great.
Maybe still 4 risers, to facilitate work and play on ground handling. It also facilitates the use of acceleration or trimers.

The dream includes the possibility that a manufacturer wants to put it into production, even keeping 100% the GNU concept of freedom, plans free for copying, and modifications include. From here I appeal to any individual or manufacturer who wants to help me build and tune this new project.

Also, if the gnuLAB2 was the mold of the simple surface BarretinaHyperLite (same basic geometry but different profile), the gnuLAB3 will be the mold for the BarretinaHyperLite2.

2. THE GNULAB3 AIRFOIL

The airfoil is the new gnuLAB3, stable and fast! Download here: gnuLAB3.txt  gnuLAB3.dat  gnuLAB3.dxf

gnuLAB3 airfoil
Fig. 1: gnuLAB3 airfoil view in LibreCAD

gnuLAB3 airfoil
Fig 2. gnuLAB3 airfoilt in XFLR5 at Re=1e5, M=0.03, alpha=5║

gnuLAB3 airfoil Cm vs alpha
Fig 3. gnuLAB3 airfoil Cm vs alpha. When Cl=0 Cm=+0.004 at alpha=-1.35║

3. THE PRE-PROCESOR

Although not strictly necessary, I thought to build a geometry pre-processor for LEparagliding, to help define the planform of the new glider. When we define the planform and the vault of the glider, in LEparagliding normally we use a CAD program. However, I have also prepared some pieces of FORTRAN code to define in the more beautifully fully analytical form, the leading edge, trailing edge, and the vault of the family gnuLAB2 Bat35 Bat45 BHL/BatLite... For this, I use circles, ellipses, parabolas, and cosinus ... According to the analytical and geometric procedimient shown here: LEparagliding pre-processor



TeiÓ, October 4th 2012

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