u3aea04 elements of aeronautics

U3AEA04ELEMENTS OF AERONAUTICS

Mr. SYED ALAY HASHIMAssistant Professor

Department of Aeronautical EngineeringVEL TECH Dr. RR & Dr. SR TECHNICAL UNIVERSITY

ChennaiINDIA

I to V

UNIT

POWER POINT PRESENTATION

AIRCRAFT COMPONENTS

TYPES OF WING

1. Monoplane

2. Biplane

3. Tandem wing

4. Triplane 

5. Quadruplane 

6. Multiplane 

7. Canard wing

SWEEP WING

Leading edge extensions of various kinds

AIRCRAFT HISTORICAL RECORDS

IntroductionAEROSPACE ENGINES

• Comprehend the basic components of gas turbine engines and their basic operations

• Comprehend the thermodynamic processes occurring in a gas turbine engines

• Comprehend the support systems associated with gas turbine engines

GAS TURBINE CYCLE

Single stage Ideal gas turbine cycle

Two stage turbine cycle

Gas Turbine Cycle

Gas Turbine Cycle

Two stage Compressor and Turbine cycle

Jet Propulsion Cycle

In practical or actual cycle Entropy is not constant

Jet EngineBasic Components

Compressor

• Supplies high pressure air for combustion process• centrifugal flow and Axial flow

• Centrifugal Compressor• Adv: simple design, good for low compression ratios (5:1), strong• Disadvantage: Difficult to stage, less efficient, high frontal area

CompressorAxial flow • Good for high compression ratios (20:1)• Most commonly used

Turbine

• Convert the kinetic energy into expansion work• It is used to drive the compressor as well as propeller shaft

Comparison of Gas Turbine and Piston Engine

Classification of Engine

Jet Engines Reciprocating Engines(Propulsive thrust is produced by jet)

Air Breathing Engine Non-Air Breathing Engine

(Using atm air to produced Power)

Engine

Gas Turbine Engine Non-Gas Turbine Engine

Turbojet Turboprop Turbofan Turbo-shaft

Ramjet Scramjet Pulsejet

(Presents of Fuel and absents of Air instead of Air + Oxidizer. Hypersonic

vehicles, Operating Mach No : 15 to 20)

(Available moving parts likeCompressor and Turbine)

(No moving parts)

Rocket Engine(No moving parts)

Turbojet

Chemical energy is converted into mechanical energy 100% Thrust produced by Nozzle Operating Mach No: 1 to 2 Supersonic Aircraft (1 to 5)

Turbofan

20 to 40% of Thrust produced by Nozzle 60 to 80% of Thrust produced by Fan Operating Mach No: 0.4 to 0.8 High Subsonic Aircraft (0.3 to 0.8)

Turboprop

20 to 25% of Thrust produced by Nozzle 75 to 80% of Thrust produced by Propeller Operating Mach No: 0.4 to 0.65 Subsonic Aircraft (0.1 to 0.8)

Turbo Shaft

High pressure turbine is used to rotate HP & LP Compressor

Low pressure turbine is used to rotate output Shaft

No Thrust produced in the exit turbine gas

Turbo Shaft

Kinetic energy is converted to Shaft power 100% Thrust produced by Shaft Operating Mach No: 0.4 to 0.8 High speed Subsonic helicopter (0.3 to 0.8)

Pulse Jet

Made up of few moving parts Valved engines use a mechanical valve to control the flow of expanding exhaust,

forcing the hot gas to go out the back of the engine through the tailpipe Starting the engine usually requires forced air and an ignition method such as a

spark plug for the fuel-air mix. It can operate statically

Rocket Engines

A rocket is a machine that develops thrust by the rapid expulsion of matter A rocket is called a launch vehicle when it is used to launch a satellite or other

payload into space Rocket engines are reaction engines The highest exhaust velocities It is used in missile

Passenger airplanes

Sl. No. Description Less Moderate High

1 Specific fuel consumption Turbofan Turboprop Turbojet

2 Noise Level Turbofan Turboprop Turbojet

3 Operating Mach No Turboprop Turbofan Turbojet

4 Take off Thrust Turbojet Turbofan Turboprop

5 Altitude Turboprop Turbofan Turbojet

6 Load Carrying capacity Turbojet Turboprop Turbofan

7 Specific Impulse Turbojet Turboprop Turbofan

Thrust Equation

Total Thrust = Momentum Thrust + Pressure Thrust

mi=mj (mass flow rate) Inlet pressure = Exit pressure Thrust force is the forward motion of engine

Factors Affecting Thrust

PRESSURE

TEMPERATURE

DENSITY

HUMIDITY

ALTITUDE

FORWARD VELOCITY

Methods of Thrust Augmentation

After burning High thrust for short duration It is used only in take-off (or) for high climbing rates Additional fuel is burning in the tail pipe between the turbine and exhaust

nozzle It is increased the jet velocity

Oxidizer-Fuel Mixture Increase the mass flow rate Evaporative cooling which produces higher pressure and higher mass flow

rate Increase the compressor pressure ratio due to reduced compressor air flow

Water and menthol or alcohol Mixture

After burner

Oxidizer-Fuel Mixture

Evaporative cooling which produces higher pressure and higher mass flow rate

Advantages of Gas turbine Engines

• Weight reduction of 70%• Simplicity• Reduced manning requirements• Quicker response time• Faster Acceleration/deceleration• Modular replacement• Less vibrations• More economical

Disadvantages of Gas Turbine Engines

• Many parts under high stress• High pitched noise• Needs large quantities of air• Large quantities of hot exhaust (target)• Cannot be repaired in place

TYPES OF FUSELAGE STRUCTURE

FUSELAGE DESIGN

WING STRUCTURE

Thank you