Solar Airplane

1

Seminar OnSOLAR PLANE

ByNiraj Namdev Petkar

( Roll No. 13M223)

GuideProf. A. A. Nikam

DEPARTMENT OF MECHANICAL ENGINEERING

DEPARTMENT OF MECHANICAL ENGINEERING 2

CONTENTSIntroductionBasic ConceptsSolar IrradianceSolar CellMaximum Power Point TrackerEnergy StorageElectric MotorAerodynamics of A WingPropellerSolar Power Airplane Advantages And DisadvantagesConclusion


INTRODUCTION

The amount of energy the sun sends towards our planet is 35000 times more than we currently produce and consume.

This energy can be easily used for practical purposes.A solar aircraft is the one which collects energy from the sun by the means of

photovoltaic solar cells.The energy may be used to drive the electric motor to power the aircraft.Our basic principle is use solar power by means of aircraft and this thing can be

done by solar panels which covers the whole surface of wing.During the night, the only energy available comes from the battery.


HISTORY OF SOLAR POWERED VEHICLESTheir are two types of solar powered airplanes as follows,Unmanned Solar Powered Airplanes:

Sunrise I (1974)Solaris (1976)Solar Excel (1990)

Manned Solar Airplanes:Solar Riser (1979)Solar Challenger (1981)Helinet (1998)Solar Impuse And Solar Impuse 2 (2009)


BASIC PRINCIPLE OF OPERATION

Solar power conversion into electric energy by means of aircraft.It can be done by solar panels which covers the definite surface area of wings.A convertor ensures that the solar panels are working at their maximum power

point.The electric energy is used to charge battery which drives electric motor.Propeller is mounted on motor shaft produces thrust continuously.


SOLAR IRRADIANCE

Solar Irradiance is a measure of the irradiance (Power per unit area on the Earth's surface) produced by the Sun in the form of electromagnetic radiation.

SOLAR CELLS

A solar cell or photovoltaic cell is a device that converts solar energy into electricity by the photovoltaic e ect. ff

It is very widely used in space application because it allows a clean and long-duration source of energy requiring almost no maintenance.

Solar cells are composed of various semiconducting materials, constituting one or more layers.


CURRENT AND VOLTAGE OF SOLAR CELL

When the cell pads are not connected, no current produced and the voltage equals

V= 0, the open circuit voltage.

When it is short circuited, the voltage is zero but the current equals ISC.

In between these two points where in both cases the power retrieved is zero, there

is working point, called the maximum power point.

The current of a solar cell is proportional to its area and varies almost linearly

with the light intensity


MAXIMUM POWERPOINT TRACKER

A solar cell has a working point on its current to voltage curve where the power retrieved is maximum.

The constantly changing irradiance conditions, and thus get the highest amount of energy, a so called Maximum Power Point Tracker (MPPT) is required.

An MPPT is basically DC/DC converter with variable and adjustable gain between the input and the output voltage.

The input being the solar panels and the output the battery. It contains electronics that monitor both the current and the voltage on each side.


POWER STORAGEWhen the energy production is not constant and continuous, a good energy

storage method is necessary. Di erent ways to store energy:ff

Chemical (hydrogen, biofuels)Electrochemical (batteries, fuel cells)Electrical (capacitor, super capacitor, superconducting magnetic energy

storage)Mechanical (compressed air, flywheel)Thermal

In the case of a solar airplane, the gravimetric energy density also called specific energy. The peak power are the most crucial parameters that determine the choice of the energy storage method.

Therefore in present case, the electrochemical batteries and the fuel cells are the two best candidates.


ELECTROCHEMICAL BATTERIES

Electrochemical batteries are energy storage devices, which are able to convert chemically stored energy into electrical energy during discharging.

They are composed of a cathode and an anode, made of two dissimilar metals that are in contact with an electrolyte.

When all elements are in contact with each other, a flow of electron is produced.


FUEL CELLS

A fuel cell is a system where the chemical energy of reactants, often a gaseous fuel and the oxygen.

The fuel cell consists of two electrodes, known as the anode and cathode that are separated by an electrolyte.

A fuel cell on a solar airplane to store the energy during the day and reuse it during the night.


ELECTRIC MOTORAn electric motor uses electrical energy to produce mechanical energy.There are a very large variety of electric motors that coexist because of the different

supply sources, sizes, torques and speeds depending on the application.In the present case, DC (Direct Current or Continuous Current) motor will be used as

solar airplane is designed to run on DC electric power supplied by a battery.The advantages of DC motors are numerous:1. Very precise speed control.2. High efficiency.3. Reliability with longer lifetime (no brush abrasion and no ionizing sparks).4. Their power to weight ratio is exceptionally high.


AERODYNAMICS OF WINGS

The design and analysis of wings of aircraft is principle application of science of aerodynamics.

Once a plane leaves the ground, it is acted upon by four aerodynamic forces.

ThrustDragWeightLift

The lift maintains the airplane compensating the weight.The drag that is compensated by the thrust of the propeller.


CONCEPT OF LIFT

The air flow meeting the leading edge of the object is forced to split over and under the object.

Due to the pressure gradient and the viscosity of the fluid, the flow over the object is accelerated down along the upper surface of the object.

The two sections of the fluid each leave the trailing edge of the object with a downward component of momentum, producing lift.


AIRFOILAn airfoil is any surface producing more lift than drag when passing through the

air at a suitable angle. Airfoils are most often associated with production of lift. Airfoils are also used

for stability (fin), control (elevator), and thrust or propulsion (propeller or rotor). AIRFOIL TYPES

Symmetrical Airfoil : The symmetrical airfoil is distinguished by having identical upper and lower surfaces. The mean camber line and chord line are the same on a symmetrical airfoil, and it produces no lift at zero.

Nonsymmetrical Airfoil (Cambered): The nonsymmetrical airfoil has different upper and lower surfaces, with a greater curvature of the airfoil above the chord line than below and have mean camber and chord line are different.

The nonsymmetrical airfoil design can produce useful lift at zero.


PROPELLER

The propeller is a device consisting of a set of two or more twisted, airfoil shaped blades

The blades are mounted around a shaft and spun to provide propulsion of a vehicle through a fluid.

It accelerates incoming air particles creating a reaction force called thrust.


SOLAR POWER AIRPLANE ADVANTAGES AND DISADVANTAGES

Advantages:1. Sunlight is renewable day after day.2. After equipment and set-up costs, solar energy is free and we save money.3. Solar energy is a clean energy. It does not pollute air.4. Solar energy which not used during the day can be stored in a battery system.

Solar Energy Disadvantages:1. Collecting solar energy depends on location and weather conditions.2. Equipment is expensive at initially.3. Solar panels and other collectors take up a lot of space.4. We cannot produce solar electricity at night.


CONCLUSION It has the advantage and very versatile and usable for less than one meter

wingspan to manned airplanes.The design methodology consists of simple 5 parameters linked to the design of

the airplane and they are as follows,1. Solar Cell2. Energy Storage3. Electric Motor4. Aerodynamic of Wings5. PropellerIt should helpful to getting the layout of a solar airplane with suitable size, weight

and powering information.

REFERENCES

History of Solar Flight. (http://www.wikipedia.com.uk/ hist.htm)Solar-Impulse Website. ( http://www.solar-impulse.com)www.solarimpulse.com

THANK YOU

http://www.wikipedia.com/

http://www.solar-impulse.com/

Engineering

Solar Airplane