mechanical aspects in stealth technology

Welcome

STEALTH TECHNOLOGY

Presented By BIPIN KUMAR JHA

TEME A-30

M e c h a n i c a l A s p e c t s I n

Mechan ica l Aspec ts in S tea l th Techno logy

Designed & Prepared by___ BIPIN KUMAR JHA

Stealth is a technique in which we can make any object partially invisible.

Stealth is an important technology which used in military operations.

Stealth technology also known as LO Technology (Low Observable Technology).

INTRODUCTION

What is Stealth Technology ?



HISTORY

The first “Stealth" aircraft have been developed in Germany during the last years of World War- II.

This technique has also used in ships.

Later Americans worked on stealth technology and succeeded.



The F-117A Nighthawk Stealth Fighter, a single seat, twin engine aircraft developed by Lockheed Martin, was the first aircraft designed to exploit low-observable stealth technology.



RADAR RADAR is the acronym for Radio Detection And Ranging Radar is an object-detection system that uses radio waves to determine the range,

altitude, direction, or speed of objects Radar is something that is in use all around us, although it (radio waves) is

normally invisible. Air Traffic Control uses radar to track planes both on the ground and in the air, and

also to guide planes for smooth landings. NASA uses radar to map the Earth and other planets, to track satellites and space

debris and to help with things like docking and manoeuvring. The military uses it to detect the enemy and to guide weapons.



http://science.howstuffworks.com/satellite.htm

When people use radar, they are usually trying to accomplish one or all of the following three things:

a. Detect the presence of an object situated at some distance

b. Detect the speed of an objectc. To map or locate something

All three of these objectives can be accomplished using: ECHO DOPPLER SHIFT



ECHO• Echo is something you experience all the time. If you

shout into a well or a canyon, the echo comes back a moment later.

• The echo occurs because some of the sound waves in your shout reflect off of a surface (either the water or canyon wall) and travel back to your ears.

• The length of time between the moment you shout and the moment that you hear the echo is determined by the distance between you and the surface that creates the echo.



DOPPLER SHIFT Doppler shift occurs when sound is generated by, or reflected off of, a moving object. Let's say there is a car coming toward you at 60 miles per hour (mph) and its horn is blaring. You will hear the horn playing one "note" as the car approaches, but when the car passes you the

sound of the horn will suddenly shift to a lower note. It's the same horn making the same sound the whole time. The change you hear is caused by

Doppler shift.



HOW RADAR WORKS??• The radar dish or antenna

transmits pulses of radio waves or microwaves that bounce off any object in their path.

• The object returns a tiny part of the wave's energy to a dish or antenna that is usually located at the same site as the transmitter.



HOW TO MAKE THINGS INVISIBLE ?The goal of stealth technology is to make an airplane invisible to radar. There are two different ways to create invisibility:

The airplane can be Shaped (Design) so that any radar signals it reflects are reflected away from the radar equipment.

The airplane can be covered in Materials that absorb radar signals (also called as Radar Absorbing Materials “RAM”).

Apart from these things, the manufacturer should also consider the following……….



Principle OF STEALTH Technology

Infrared detection.Visual detection.Acoustic detection.Radar detection. Reduction in these detection is the principle of stealth

technology.



RADAR CROSS-SECTION REDUCTIONS

Almost since the invention of radar, various techniques have been

tried to minimize detection.

Some of the techniques used for this purpose are:

1. Vehicle Shape & Design, and

2. Radar Absorbing Material (RAM)



Most conventional aircraft have a rounded shape. This shape makes them aerodynamic, but it also creates a very efficient radar reflector. The round shape means that no matter where the radar signal hits the plane, some of the signal gets reflected back.

A stealth aircraft, on the other hand, is made up of completely flat surfaces and very sharp edges. When a radar signal hits a stealth plane, the signal reflects away at an angle, like this:

Difference Between Conventional & Stealth Aircraft Design



STEALTH VECHICLE SHAPES & DESIGN It should be coated with the Radar Absorbing Materials. It’s tail should kept an ACUTE angle. Planes wings has to kept at Angle. Design of Nose. Stealth aircraft must bury the Engines within the wing or fuselage. A corner reflector is a retro reflector consisting of three

mutually perpendicular, intersecting flat surfaces, which reflects electromagnetic waves back towards the source.



What is Radar Absorbing Materials (“RAM”)?√ RAM is a class of materials used in stealth technology to disguise

vehicle or structure from radar detection.√ RAM reduces the radar cross section making the object appear

smaller.√ These materials are both very heavy and very costly, two key

limitations to their adoption for many applications.√ Materials

Carbon fiber composites Magnetic Ferrite-based substance



The material that is used to paint the stealth can be made of special materials like carbon powder in the glue or silicon based inorganic compound that would the waves that fall on the plane.

Dielectric materials are used as they are transparent to radar waves.

Composites of ferrites are used to optimize dielectric and magnetic properties



REDUCING INFRARED SIGNATURE

Infrared radiation are emitted by all matter above absolute zero temperature.

Hot materials, such as engine exhaust gasses or wing surfaces heated by friction with the air, emit more infrared radiations than cooler material.

Embedding jet engines inside the wings is one basic design step towards infrared stealth.

Other measures include extra shielding of hotter parts, mixing of cooler air with hot exhausts before emission etc.Mechan ica l Aspec ts in S tea l th

Techno logyDesigned & Prepared by___ BIPIN KUMAR

JHA

REDUCING ACOUSTIC SIGNATURE

The engines of the stealth planes should be designed such that the noise emitted by them is minimum.

Engines should be placed deep inside the plane.Slow turning propellers were used to minimize the

noise in earlier designs to avoid detection by enemy troops.

Incorporating acoustic-stealth measures, including sound-absorbent linings inside its engine intake and exhaust cowlings.



LIMITATIONS OF STEALTH1. Instability of design2. Aerodynamic limitations3. Reduced payload4. Cost of maintenance5. Sensitive skin6. Cost of operations



ADVANTAGES OF STEALTH1. Reduce the casualty rate during the war.

2. Develop the military secretes.3. Bluff the anti-detective device .4.Lesser number of stealth aircrafts required. 5. We can perform spy mission.6. Can be used in Civil aviation.



STEALTH HELICOPTER Newest addition in stealth technology. Designs for blades have emerged that can significantly reduce noise. Used for raid on the compound of Osama bin Laden on May 2, 2011.



NORTHROP GRUMMAN B-2 SPIRIT

Particular Strategic Stealth BomberNational origin U.S.AManufacturer Northrop Grumman

CorporationFirst flight 17 July 1989Introduction April 1997Status In servicePrimary user United states air forceProduced 1988-2000Number built 21Unit cost $737 million



B 2 SPIRIT

Max speed= Mach 0.95

Range = 11,100 km

Service Ceiling= 15,200 kmThrust/Weight = 0.205

National origin : U.S.A



BIPIN KUMAR JHA

1 Mach Speed = 1224 kph1 Kph speed= 0.000816993 Mach

LOCKHEED MARTIN F 22 RAPTOR

Role Stealth air superiority fighter

National origin U.S.AManufacturer Lockheed MartinFirst flight 7 Sep. 1997Introduction 15 Dec. 2005Status In servicePrimary user U.S air forceProduced 1996-2011Number built 195Unit cost $150 millionMechan ica l Aspec ts in S tea l th Techno logy


F 22 RAPTOR



F-35LIGHTNING II

Role Stealth multirole fighterNational origin

U.S.A

Manufacturer Lockheed Martin First flight 15 DEC 2006Introduction Dec 2015Status In initial production and

testing, used for training by U.S

Primary users U.S air forceProduced 2006- presentNumber built 100 as of 2013Unit cost $252.3 millionMechan ica l Aspec ts in S tea l th Techno logy


INDIA’S STEP TOWARDS STEALTHHAL : LIGHT COMBAT HELICOPTER (LCH)



HAL LIGHT COMBAT HELICOPTERRole Attack helicopterNational origin IndiaManufacturer Hindustan

Aeronautics LimitedFirst flight 29 march 2010Status Development trialsPrimary users Indian Army

Indian Air ForceProduced 2010-presentNumber built 3Unit cost $17.48 million

General characteristics • Crew: 2 • Length: 15.8 m • Rotor diameter: 13.3 m • Height: 4.7 m • Disc area: 138.9 m² • Max. take off weight: 5,800 kg • Power plant : 2 × HAL/Turbo meca Shakti turbo shaft, 1,067 kw each • Never exceed speed: 330 km/h (178 knots, 207 mph) • Maximum speed: 268 km/h (145 knots, 167 mph) • Range: 700 km (297 nmi, 342 mi) • Service ceiling: 6,500 m (21,300 ft)



BIPIN KUMAR JHA

1 knots= 0.5144444m/s

SUKHOI T-50 STEALTH FIGHTER



FUTURE INDIAN STEALTH AIRCRAFTSDRDO-AURA

AURA (Autonomous Unmanned Research Aircraft) Role -Unmanned Stealth Bomber Manufacturer- DRDO Designer- DRDO First flight- 2015 Introduction -2019-2020 Status -Under Development Primary user- Indian Air Force

Indian Navy



FUTURE INDIAN STEALTH AIRCRAFTSHAL AMCA



HAL AMCA

Advanced Medium Combat Aircraft Role -Stealth multirole fighter Manufacturer-

Hindustan Aeronautics Limited Designer –

Aeronautical Development AgencyDRDO

First flight- Early 2020s Status- Under development Primary users - Indian Air Force

Indian Navy Mechan ica l Aspec ts in S tea l th Techno logy


FUTURE SCOPEHypersonic- the idea is to travel with M>5 to avoid detection.The infrared Invisibility Cloak: Shield one’s body heat from infrared sensors, effectively making them invisible to infrared cameras.Plasma Stealth Technology: Also knows as Active Stealth Technology Uses plasma to reduce the overall radar cross section of an aircraft.TARANIS: A semi autonomous unmanned war plane designed to fly intercontinental missions. It will carry a variety of weapons enabling it to attack both aerial and ground targets.To be incorporated not only in fighters and bombers but also in ships, helicopters, tanks and transport planes.Mechan ica l Aspec ts in S tea l th Techno logy


CONCLUSION

• Undoubtedly, Stealth technology is the Future of Military Combat and at Present is one of the best technology to make things invisible as far as possible.

• But, the main problem with stealth is its very high cost and because of this, not all nations can adopt this technology.

• So we need to find ways to reduce cost or adopt a different technology with Stealth like characteristics and at low cost (Nano technology).



REFERENCES Book on Stealth technology-the art of black magic by J.JONES Book on Stealth aircraft by BILL SWEETMAN • Future Flight: The Next Generation of Aircraft Technology, William D. Siuru , Jhon D. Busick, Published

1933 McGrew-Hill Professional, 194 pages, ISBN 0830643761• Have Blue and the F-117A: Evolution of “Stealth Fighter”, By David C. Aronstein, Albert C Piccirillo,

Published 1997 American Institute of Aeronautics and Astronautics, 305 pages, ISBN 1563472457• Stealth technology: The Art of Back Magic, By J. Jones, Matt Thunder• http://www.geocities.com/Area51/Shadowlands/6583/projects.html• http://en.wikipedia.org/w/index.php?title=Stealth_aitcraft• http://en.wikipedia.org/wiki/F-117_Nighthawk



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mechanical aspects in stealth technology

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