gnuLAB3 "Barretina 2"
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
A new dream
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 behavior 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.
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
From here I appeal to any individual or manufacturer who wants to help me build and tune this new project.
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
Fig. 1: gnuLAB3 airfoil view in LibreCAD
Fig 2. gnuLAB3 airfoilt in XFLR5 at Re=1e5, M=0.03, alpha=5║
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
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
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