JEC COMPOSITES MAGAZINE - Issue #80 - April 2013 - 50

energy

An innovative composite
energy efficiency solution

Christian HUGUES
President
Minix

Minix is an innovative wing-tip device for land, sea and air
applications that procures a net economic gain of 6% per aircraft
in aviation and a 14% average annual increase in power production for wind or submarine turbines. This could be a boon for the
owners of wind farms that have reached their end of warranty
(usually the fifth year). After a series of tests, a license for the
internationally patented invention was sold in the U.S. in July
2012.

Nature abhors a vacuum

ver since the Wright brothers turned
man’s dream of flying into reality
with their first successful flight in
North Carolina in 1903, the airplane –
from miniature to jumbo and at whatever
speed – has been a source of fascination
for all.

Induced drag
From the early stages of flight on, constant
progress has been made in reducing
various types of parasitic drag, but it has
never been possible to significantly reduce
induced drag and the wing-tip vortices
associated with it.
Induced drag can never be completely
eliminated, as it is associated with an
aircraft’s lift. It acccounts for 33 % of total
drag at high velocity and for during climb,
and for 70-80 % during take-off.Induced
drag is inversely proportional to the
square of the velocity, while parasitic drag
(the other component of total drag) is
directly proportional to the square of the
velocity. Reducing drag by 1% can save
airline companies millions of dollars in
fuel consumption. More than 5% of global
pollution is generated by the aviation
industry.

Everything is governed by the forces
and counterforces created by vacuum.
Turbulence will form at the wing tip, no
matter what barrier is placed there. With
this conclusion as a starting point, Minix
President Christian Hugues decided to
delve into the problem, focusing research
on a specific shape to reduce the helical
movement of induced drag.
Mr Hugues started in 1997 by creating
a rudimentary prototype equipped
with tufts of red wool. He attached the
prototype to the roof of his car, observing
it and monitoring the changes through
the vehicle’s sun roof at high speed on the
motorways. He noticed that the tufts of
wool moved in the right direction.
After a number of wind-tunnel test series
on 28 different prototypes, he finally
obtained a very interesting result, and
continued his research with five series
of numerical tests on an airplane, where
he achieved a net 6% gain for the entire
aircraft.
Given the rising interest in the wind
energy sector, he also did eight series of
numerical tests on the American National
Renewable Energy Laboratory’s NREL
wind turbine, obtaining a 14% average
annual increase in energy efficiency, with
lower vibration over the entire structure

50 jec composites magazine / No80 April 2013

Boeing 747 Vortex out of cloud

and no change in axial thrust.
Since then, 14 patents have been filed,
including two in the United States. In
April and June 2012, real flight tests were
done on Van’s Aircraft RV4 and RV8
models, with even better results than with
the laboratory and numerical wind tunnel
tests.
Two other tests are scheduled for 2013 in
Europe on RV7 and RV8 models.

How the Minix operates
This invention is based on three different
kinds of pressure: the field pressure in
front of the aircraft, the suction pressure
generated on the upper surface (extrados),
and the positive pressure generated on the
lower surface (intrados).
The airplane’s wing tip is continuous with
the leading edge of the Minix, which has
a droplet-shaped intake. This specific

JEC COMPOSITES MAGAZINE - Issue #80 - April 2013

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #80 - April 2013