GUIDED BY: P MOHAPATRAR.R SWAINB.K SATPATHY

• INTRODUCTION• STEALTH TECHNOLOGY• HOW STEALTH WORKS?• HISTORY OF STEALTH• PLASMA STEALTH• WHAT IS RADAR?• RADAR CROSSECTION DESIGNS• RADAR ABSORBING MATERIAL(RAM)• B-2 SPIRIT BOMBER• ADVANTAGES OF STEALTH TECHNOLOGY• DISADVANTAGES OF STEALTH TECHNOLOGY• FUTURE OF STEALTH• CONCLUSION• REFERENCES• QUERIES

• Stealth technology referred as “VLO” i.e “VERY LOW OBSERVABLE TECHNOLOGY”

•Fighter planes are so made that they are harder to be detected by the radar and other devices

•The first combat use of stealth aircraft was in December 1989 during Operation Just Cause in Panama

•Well known examples include the United States' F-117 Nighthawk (1980s-2008), the B-2 Spirit "Stealth Bomber," and the F-22 Raptor

Stealth Technology

Scientifically know as

LOW OBSERVABLE.

Used in military aviation

Reduces detection range

of an aircraft

Partial indivisibility to

radar and other detection

• 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 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.

• 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

The first “STEALTH” aircraft

have been developed in Germany

during the last years of WWII.

This technique has also been used

in ships.

Later Americans worked on

stealth technology and succeeded.

In this stealth the aircraft injects a

stream of ionized gas

Plasma stealth is a proposed process to use ionized gas (plasma) to reduce the radar cross section (RCS) of an aircraft. Interactions between electromagnetic radiation and ionized gas have been extensively studied for many purposes, including concealing aircraft from radar as stealth technology. Various methods might plausibly be able to form a layer or cloud of plasma around a vehicle to deflect or absorb radar, from simpler electrostatic or radio frequency (RF) discharges to more complex laser discharges. It is theoretically possible to reduce RCS in this way.

What Is RADAR ?

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

2.Radar absorbing material

Radar Absorbing Materials

Design of NOSE

Stealth aircraft must bury the

engines within the wings

Date

Normal fighter plane

showing the engine

Engines of the stealth aircraft

are covered

Exhaust PLUME of a

normal plane

Stealth Aircraft without

Exhaust

Nanostructural composite material,

absorbing without reflecting radar

wave.

Magnetic ferrite-based substance

RAM reduces the radar cross

selection making the object appear

smaller.

The B-2 bomber has a completely different design: It's one big wing, like a boomerang.

This flying wing design is much more efficient than a conventional plane. Instead of separate wings supporting all the weight of the fuselage, the entire craft works to generate lift. Eliminating the tail and fuselage also reduces drag -- the total force of air resistance acting on the plane.

Greater efficiency helps the B-2 travel long distances in a short period of time. It's not the fastest craft around – It’s high subsonic, meaning its top speed is just under the speed of sound (around 1,000 ft/sec or 305 m/s) -- but it can go 6,900 miles (11,000 km) without refueling and 11,500 miles (18,500 km) with one in-flight refueling.

The B-2's flat, narrow shape and black coloration help it fade into the night. Even in the daytime, when the B-2 stands out against blue sky, it can be hard to figure out which way the plane is going. The B-2 emits minimal exhaust, so it doesn't leave a visible trail behind it.

The B-2's engines are buried inside the plane. This helps muffle the noise. The efficient aerodynamic design helps keep the B-2 quiet as well, because the engines can operate at lower power settings.

The engine system also works to minimize the plane's infrared (heat) signature. Infrared sensors, including those on heat-seeking missiles, typically pick up on hot engine exhaust. In the B-2, all of the exhaust passes through cooling vents before flowing out of the rear ports. Putting the exhaust ports on the top of the plane further reduces the infrared signature

The stealth bomber's peculiar shape deflects radio beams in both ways. The large flat areas on the top and bottom of the plane are like tilted mirrors. These flat areas deflect most radio beams away from the station, presuming the station isn't directly beneath the plane.

The plane itself also works like a curved mirror, particularly in the front section. The entire plane has no sharp, angled edges -- every surface is curved in order to deflect radio waves. The curves are designed to bounce almost all radio waves away at an angle.

The B-2's body is mainly composed of composite material --combinations of various lightweight substances. The composite material used in the B-2 bomber is specifically designed to absorb radio energy with optimum efficiency. Parts of the B-2, such as the leading edge, are also covered in advanced radio-absorbent paint and tape.

General characteristicsCrew: 2: pilot and commander (co-pilot)Length: 69 ft (21.0 m)Wingspan: 172 ft (52.4 m)Height: 17 ft (5.18 m)Wing area: 5,140 ft² (478 m²)Empty weight: 158,000 lb (71,700 kg)Loaded weight: 336,500 lb (152,200 kg)Max. takeoff weight: 376,000 lb (170,600 kg)Powerplant: 4 × General Electric F118-GE-100 non-afterburning turbofans, 17,300 lbf(77 kN) eachFuel Capacity: 167,000 pounds (75,750 kg)

PerformanceMaximum speed: Mach 0.95 (550 knots, 630 mph, 1,010 km/h) at 40,000 ft altitude / Mach 0.95 at sea levelCruise speed: Mach 0.85 (487 knots, 560 mph, 900 km/h) at 40,000 ft altitudeRange: 6,000 nmi (11,100 km (6,900 mi))

Role Strategic stealth bomber

National origin United States

ManufacturerNorthrop CorporationNorthrop Grumman

First flight 17 July 1989

Introduction April 1997

Status In service

Primary user United States Air Force

Produced 1988–2000

Number built 21

Program cost US$44.75 billion (through 2004)

Unit cost$737 million (1997 approx. flyaway cost)

Reduces the causality rates

during war

Saving military budget.

Develop the military secretes

Bluff the anti-detective device

Stealth aircraft are invisible to

radar

.

Future Of The STEALTH

Stealth technology developed a lot.

Investment needed is very high.

High chance of low cost gain.

A lot learned about signature reduction and absorption.

Success yet to be proved extensively.

Useful for other projects.

Date

References:

1. http://www.totalairdominance.50megs.com/stealth.htm

2. http://en.wikipedia.org/wiki/Stealth_technology

3. http://en.wikipedia.org/wiki/Radar

4. http://en.wikipedia.org/wiki/Stealth_ship

5. http://www.resonancepub.com/images/stealth_ship.gif6. http://images.google.co.in/images

7. http://www.airplanedesign.info/51.htm8. http://www.military-heat.com/43/russian-plasma-stealth-fighters/