UWE Bristol Engineering showcase 2015

Batteries
Electrochemical batteries are energy storage
devices, which are able to convert chemically
stored energy into electrical energy during
discharging. They are divided in two subgroups,
the primary batteries are non-rechargeable and
secondary batteries are rechargeable.
Typically, there are three types of batteries that
are mostly used for airplanes that are driven by
electrical motors, and these are the following:
- Nickel Cadmium (NiCd)
- Nickel Metal Hydride (NiMH)
- Lithium Polymer (LiPo)
Mehmet Esat Erzurumluoglu
Solar Powered Unmanned Aerial Vehicle (UAV)
B.Eng. Individual Project UFMFX8-30-3
Aerospace Engineer (Design)
Introduction
Compared to other transport vehicles, aircraft can be classified as low emissions producers. An typical mid-ranged Airbus consumes 2785 litres kerosene per
100 kilometres. Calculated per person every passenger needs 2.9 litres kerosene per 100 kilometres (Airbus, 2014). The best case is to reduce the fuel
consumption to zero and for that it is necessary to switch from fossil fuels to renewable energy. Solar cell technology lends itself as a suitable application which
can support the propulsion system with energy. Using solar cells in the transport aircraft category is less effective because the energy produced by the solar
cells is only a fraction of the energy from fossil fuels. For small aircraft like a model aircraft or an unmanned aerial vehicle where the payload is less, such an
energy supporter as solar cells could be imagined. The application of unmanned aircraft will increase in the future, particularly in missions where an aircraft
operates in dangerous areas or under excessive stress. Through the elimination of the pilot and miniaturization of the aircraft the cost of a flight task is reduced
or new missions are possible .
Conventional configuration
The main wing is before the centre of gravity and the tail with their
rudder is after the centre of gravity. An aft-mounted tail offers
stability but produces a small down force in normal flight. In the
past most solar powered aircraft were in conventional configuration
and nearly all motor-gliders and gliders have a conventional
configuration
Aerofoil selection
For my UAV I had investigated a suitable aerofoil
and chose the best on that will give the
following.
An aerofoil capable of producing high lift at very
low speeds.
An aerofoil design capable of carrying as much
payload as possible
An aerofoil capable of being launched from a
low height and obtaining cruise speed
Minimum number of three aerofoils will be
analysed for comparison.
Solar cell arrangements
Minimum of 6x12=72 solar cells required to be
placed on the wing and other suitable places on
the UAV.
So we need 12 groups of 6 parallel connected
solar cells for our motor to have efficient power
input without relying on the additional energy
from the battery
Shadow effect
It was found that high wing configuration would be the best suited
to get maximum sun ling we could and also more flat surfaces to
attach solar panels. And avoiding dihedrals and sweeps for the time
being them to
Literature review
During my background reading I took in to
concentration last 45 years of solar powered
aircrafts and tried to list them in order to see
their potential improvements as time
progresses and technology advances . And state
of the art UAVs
Wind tunnel, Javafoil and CFD results
At wind speeds of 10 m/s, Wind tunnel data shows us that NACA
2410 and 23015 show signs of instability, whereas NACA 4412
remained stable at this speed.
Judging from the wind tunnel data javafoil and cfd results, we can
conclude that NACA 4412 was the overall more stable wing as it
performed well at both wind speeds.
Supervisor: Dr. Abdessalem Bouferrouk
Project summary
Solar powered aircraft and UAV have been made known over
the last 45 years and flying with pure solar energy now a
common reality but it is still not viable produce and sell them on
commercial scale for the public interest. Most of the inventors
were engineers in areas like electronics or mechanics. With the
increasing number of Aerospace engineers there will be more
redevelopment in this field and aerodynamic aspects will no
longer be neglected and these products and these aircrafts will
not be left to mechanical or electronically engineers. To create a
UAV you would need to combine all these engineering
disciplines as I did mechanics and electronic in my previous
studies in A-levels would be ticking all the boxes t start this
project alone. The aim of this project is to improve the current
state of solar powered aircraft.
Project Objectives
The aim of this project is to improve the current state of solar
powered aircraft.
And have a possible application of the product like Atmospheric
research, Earth observation, monitoring of air and water
pollution, traffic monitoring , location tracking can all performed
by a high resolution camera and instruments mounted on a
solar powered aircraft
Project Conclusion
It had been a long journey of but gladly it came to an end I
would have liked to build the UAV if I had time and funding
required. During this project I had used some research and work
i did in previous years to help me save time as we are on final
year we had many other work to concentrate and revise for
exams and handle in dozen coursework. Therefore some of the
works provided may contain group work which i was thoroughly
involved in, I had used some spread sheets calculator to work
the maximum lift we used in Airbus coursework we did in
semester 1 to help me with the. Lastly I had input from the
wings weeks project we did in year 2 so to do this project id did
require a lot of input from my previous year experiences and
works as it was vital to finish a project this big.
Cost estimation of the project - solar powered UAV prototype.
£210 solar panels flexible ones £70 for the glass type
£20 electric motor
Batteries £100
system hardware control and aviation £100
Remote control £100
aileron motors £20
Aerofoil lathe + technician £30, foam £10, film cover £5 & beam
£5.
fuselage £100
UWE resources workshop, electric and machines irons (free)
Labour cost 30 hours £210
This gives a sum of £700 assets and £210 worth of my time if I
were to create this prototype therefore it wouldn’t be ideal
project to be accepted if the end product made was not worth
more than £1000.