EJ11 ElectroJet
Verticraft
The
EJ110 ElectroJet is a compact aircraft, very small and
designed according to the same principle that since 1996
I adopted on my first Cellcraft's
project: the G150.
This aircraft worked thanks to the combination between an APU
(Auxiliary Power Unit) and four or more eletctric propeller.
I defined this type of aircraft with the term TLS (Transmission-Less-Aircraft),
since cables replace heavy shafts and gear boxes. |
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EJ110
The EJ110 is the smallest project of this kind to which I have worked, it is in-fact the starting point for a series of four new aircraft that will be based on the same TLA technology; tested today only on smaller aircraft known as drones or multicopters. For about two years I have experienced with my little quadcopter many flight's hours, in order to explore the potential perspective of this technology, which, through a machine on a larger scale could open up interesting horizons, both teconological as well renewing the aviation industry itself. Aircraft Structure
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A
second compartment instead houses the emergency power unit EFBU
(Emegency Flight battery Unit) constituted by a Lithium
Ion battery pack, ensuring a stable flight for at least ten minutes,
in order to guarantee a safe landing in case of malfunction or breakage
of the MPU; since the machine is not capable of make
any autorotation flight. The tank can contain more than 200 liters of biofuel and is placed below the center of gravity of the aircraft, since the weight aboard multicopters aircraft can be easily shifted in a wide range, along the center of gravity. Quad-rotors are in-fact quite flexible about load balancing. The fuselage is connected through a dedicated mechanical hook to a beam support, that contains the four main rotors, which are powered by eight electric motors. Motors are induction type and electronically controlled. The motors control units are housed in the upper space of the fuselage, next to the the rotor-wing connection. The connector wing is equipped with an elastomeric bearing that dampens the oscillations, forming vibrations both lateral and longitudina axes , in order to reduce or absorb the stresses, due to landings or any in-flight maneuvers, which could mechanically stressing the whole structure. The pylons of the four engines are foldable and can rotate the two pairs of rotors down to 110 degrees, this mechanism allows easy access for the maintenance process of the machine, as well allowing it to be recovered in small space. |
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Cockpit
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The access to the cockpit is possible through the rotation of a Plexiglas dome, mounted on an aluminum frame. Although access is not very comfortable on this specific aircraft sacrificing accessibility for design reasons, it is, however, ample and comfortable for the pilot once seated in. It 'important to note that the design method that I adopt is always made on 1:1 scale size, using a virtual mannequin drawn on my physical measurements, of an individual of 1.76 cm in height and 80 kilos weight, that represents the medium size of the a pilot. MPU unit It
is a axial turbine engine, connected to a generator capable of delivering
up to 208 Kw (280Hp) maximum continous power. Both
components are very light, designed so as to replace the heavy metal
components with alternative materials, such as Teflon,
Carbon and Aluminum etc. The generator,
is made from two half-shells of carbonium that protect both the magnets
and the rotor, the rotor is mounted on a carbonium shaft instead of
the classic steel ones. The remains components are the only elements
made in metal, because some parts can't be replaceable according to
their specific duty. |
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Unlike
its predecessors, the EJ110 has been greatly improved
by the electronic point of view, if compared to the preceeding projects
of mine. The components are much smaller and less complex than those conceived
in the past. If you think that at the time of the first projects of my
TLA's aircraft type, in 1996, the chances of imaging
a similar machine for me was pretty much like a science fiction's idea.
Computers were very heavy and slow, and there were no electric motors
or powerfull processor such as those available today, or small accelerometers,
gyroscopes of such accuracy as are available today. Right now we can image
a stabilization system perfectly integrated into the main calculation's
unit, which contains a multiprocessor, two gyroscopic units and a series
of accelerometers, all fundamental elements for the computation in order
to get a perfect stabilization of the aircraft in flight. Finally
the time has come, we can design and build a machine on a larger scale
based on the same mechanisms that make smaller quad-copter drones flying
efficently. A quad-copter is able to lift a discrete
weight if compared to its structural design. The four electric motors
which typically a quad-copter is equipped with, are controlled by a dynamic
system of calculation, which keeps the rotation of the propellers independent,
varying the power delivered on each individual motor in real time, thus
maintaining the aircraft perfectly horizontal. This is possible thanks
to the combination of sophisticated computer units, dedicated software
and devices such as accelerometers; gyroscopes and small proves and sensors
evem more precise then ever. The
software is designed to guarantee maximum safety and comfort of the flight,
without losing the pleasure of piloting the aircraft. There are several
automatic flight controls as well a GPS unit installed
on the aircraft working according with the AFC unit. |
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Rotors
Rotor
system has been greatly simplified on this project if compared to previous
aircrafts. Its structure include four rotors, each one of them driven
by two electric motors, three-phases digitally controlled by a ESC
units via AFC. The electric motors are very
flat and very light, they are interchangeable and interconnected, mounted
on a support ring sustained by three steel pylons that contain three cables
for each motor. In this past years I made with my drone many test flights, the perfection of this aricraft proved that a quad-copter can quite reach a considerable high speed. In-fact I reached a top speed of 107 km per hour in forward flight at about twenty meters from the sea level, having a temperature of 24° C with a small quad-copter having a take off-off maximum weight of 2,57 kg. It is a very small aircraft but apparently more efficient for some aspect, than a conventional helicopter, it is indeed able to overcome the problem of dissymetry of lift that is a very complex limitations for single rotor aircraft such as that of a helicopter, which is rather limited at certain speeds due to this effect occuring between the advancing and the retreating blade. The four rotors are mounted on a tilting support, it is slightly upward with a positive dihedral of about 10 degrees. They can, however, be tilted downwards up to a maximum angle of 110° to allow easy maintenance on the rotors, as well easy storage of the whole aircraft in small space. |
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Safety The flight control system is designed to guarantee the maximum security, the system works as a sort of safeguard to protect the integrity of the pilot and of the machine as well. Inside the strings of the software there is a substantial part of instructions that reproduce a kind of survival instinct of the machine. The aircraft intervene to corrects any accidental maneuver performed accidentally by the pilot, mantaining always the flight withing the safety range. The
EJ110 as well as all the TLAs or Verticrafts
I designed in the past, is provided of a very efficient security system
that is automatically activated in case of emergency, the EFBU
(Emegency Flight battery Unit) in case the turbine engine would
no longer providing the required power for the flight, or it is reduced
due to an unexpected malfunction, or in case of loss of the MPU
unit. |
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The
EJ110 is the smallest aircraft of this series, it is
the result of a long researching process that saw me working also with
a Brazilian group for the development of a compact aircraft,
which would employ new technologies alternative to helicopters. The first
draft of ElectroJet was done at the beginning of 2014
with the project EJ140, a single-seater aircraft, a bit
heavy in size if compared to the very compact EJ110. |
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The
EJ140
is born solely as a cooperative project with the Brazilian group led by
the architect Claudio Medeiros, who shares with me the
idea that support this type of aircraft, new and revolutionary, from my
point of view. The EJ110 followed the initial evolution
of the EJ140,
moving even forward with four new projects mainly targeted for
commercial applications, both for passengers transportation - with the
next projects to come EJ440/445 - and a version dedicated
to aerial work like the DDRH which will have the definition
as EJ4LX1, as will be shown on this site as soon the
project will be completed. |
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©Gino
D'Ignazio Gizio |