a nanotechnology aircraft with stealth technology

International Journal of Research In Science & Engineering e-ISSN: 2394-8299 Volume: 1 Issue: 2 p-ISSN: 2394-8280

IJRISE| www.ijrise.org|[email protected] [13-18]

A NANOTECHNOLOGY AIRCRAFT WITH STEALTH TECHNOLOGY

INDRADEEP KUMAR

Aeronautical Engineering 3rd

year

MATS School of Engineering and IT, MATS University, Raipur

[email protected]

Abstract- The success of the Aviation Industry (Defense) depends on various factors ranging from less visibility, reduction

of weight, availability of materials with multifunctional properties, carrying more payload, eco-friendly fuels, less fuel

consumption, faster and highly responsive communication systems, less or no repairs, extended and safe life, reduced time

frame of development cycle from concept to implementation and many more. Nanotechnology is recognized as a very strong

innovation driver and is therefore seen as a strategic technology for the world’s future economy. Nano-materials with their

exceptional multifunctional properties may transform the functioning of aviation (Defense) industry dramatically. Stealth

properties give it the unique ability to penetrate an enemy's most sophisticated defenses and threaten its most valued and

heavily defended targets. Stealth refers to the act of trying to hide or evade detection. It is not so much a technology as

a concept that incorporates a broad series of technologies and design features. Stealth does not always refer to radar.

Reducing an aircraft's heat signature is also important. This is usually done by channeling the engine exhaust through long

tubes and mixing it with cooler outside air. This paper shows the modern aviation design requirements like faster, miniature,

highly maneuverable, self-healing, intelligence guided, smart, eco-friendly, light weight warrant for materials with

extraordinary mechanical and multifunctional properties with stealth technology. Stealth technology is the use of special

radar absorbent materials, flat angular surface design and other techniques to minimize the amount of radiation reflected to

a radar installation, causing an aircraft to appear as a much smaller signal or not at all. Stealth means 'low observable'.

KEYWORDS- Nano-craft, Nano-particle, Nano-tube, Nano-phase, Nano-scale, Thermo-phoretic, Chemical Vapor Deposition

(CVD), Particulate film, Crystallinity, Nano-clay, Nano-fibers, Stealth, Low Observability.

INTRODUCTION

The aerospace (Defense) industry is one of the most important heavy industries in the world. Countless companies rely on the

ability to ship products and people around the world with the speed that can only be achieved by air On acquiring the best

performance of Aircraft, it is necessary to find a design of Aircraft so that the efficiency (carrying payload) can be increased.

Therefore, some different methods have been proposed to increase the efficiency. These include Nano -materials. Nano

materials are cornerstones of Nano science and nanotechnology. Nano structure Science and technology is a broad and

interdisciplinary area of research and development activity that has been growing explosively worldwide in the past few years.

It has the Potential for revolutionizing the ways in which materials and products are created and the range and nature of

functionalities that can be accessed. It is already having a significant commercial impact .

Nano-scale: generally refers to the size scale of 1 nanometer (nm) = 10-9

m. It refers to the matter whose length scale, in any

dimension, is approximately 1 to 100 nanometers.

The current trend is limited to use some extent only in the fighter Aircraft but this paper is depicting where and which type of

Nano-materials can be used in almost entire Aircrafts including navigation system. The Nanotechnology is a critical enabling

technology for modern aviation and large-scale power generation with less visibility. It's extensive application, however,

Instability of the particles and Difficulty in synthesis, isolation and application. Stealth technology is a sub-discipline of military

counter measures which covers a range of techniques used with aircraft in order to make them less visible (ideally invisible) to

radar, infrared and other detection methods. Stealth technology (often referred to as "LO", for "low observability") is not a

single technology but is a combination of technologies that attempt to greatly reduce the distances at which a vehicle can be

detected.

HOW NANO MATERIALS ARE FORMED?

Nano-materials can be created with various Modulation dimensionalities as: zero (atomic clusters, filaments and cluster

assemblies), one (multilayer), two (ultrafine-grained over layers or buried layers), and three (Nano-phase materials consisting of

equi-axed nanometer sized grains).

For an fighter aircraft generally Nano-materials are formed by Gas Phase synthesis process as follows:



1. In homogeneous Chemical Vapor Deposition (CVD), particles form in the gas phase and diffuse towards a

cold surface due to Thermo-Phoretic forces, and can either be scrapped of from the cold surface to give Nano-powders,

or deposited onto a substrate to yield what is called ‘particulate films’.

2. In heterogeneous CVD, the solid is formed on the substrate surface, which catalyzes the reaction and a dense film is

formed.

3. In order to form Nano-materials several modified CVD methods have been developed. Gas phase processes have

inherent advantages, some of which are noted here:

4. An excellent control of size, shape, crystallinity and chemical composition

5. Highly pure materials can be obtained

6. Multi-component systems are relatively easy to form and Easy control of the reaction mechanisms.

PROPERTIES OF NANO-MATERIALS

Nano-materials have the structural features in between of those of atoms and the bulk materials. While most micro-structured

materials have similar properties to the corresponding bulk materials, the properties of materials with nanometer dimensions are

significantly different from those of atoms and bulks materials. This is mainly due to the nanometer size of the materials wh ich

render them:

large fraction of surface atoms;

high surface energy;

spatial confinement;

Reduced imperfections, which do not exist in the corresponding bulk materials.

Due to their small dimensions, Nano-materials have extremely large surface area to volume ratio, which makes a large to be the

surface or interfacial atoms, resulting in more “surface” dependent material properties . Especially when the sizes of Nano-

materials are comparable to length, the entire material will be affected by the surface properties of Nano-materials.

NOVEL PROPERTY

Small size effect (Quantum size effect)

--Contain very small number of atoms (molecules)

--Electromagnetic forces are dominant.

--Wave particle duality. The electrons exhibit wave behavior.

--Quantum confinement.

--Discrete energy levels

WHY NANOMATERIALS?

Nano-materials can be metals, ceramics, polymeric materials, or composite materials so it can be used anywhere in the fighter

Aircraft depending on the necessity.

Nano-materials for different Sectors of Aviation Industry

Nano-materials can be primarily used in three areas of Aviation Industry. These are:

1. AIRFRAME STRUCTURE 2. AERO-ENGINE PARTS



3. AIRCRAFT ELECTRO-COMMUNICATION SYSTEM

1. NANO-MATERIALS IN AIRFRAME STRUCTURE

Properties of Materials required for Airframe Structure:

The design requirements of the materials to be used in Airframe Structure are:

Light Weight

High Strength

High Toughness

Corrosion Resistance

Easy Reparability & Reusability

Less Maintenance & Durability

NANO-MATERIALS WHICH CAN FULFILL THE REQUIREMENTS: The modern aviation design requirements like faster, miniature, highly maneuverable, self-healing ,intelligence guided, smart,

eco-friendly, lightweight and stealth systems warrant for materials with extraordinary mechanical and multifunctional

properties.

Carbon Nano-tube (CNT) based Polymer Composites:

Properties of CNT based polymer composites are their wide range of Young’s Modulus, High Specific Strength, Crash

Resistance and Thermal Performance and these properties can provide conventional composites and light weight metals. Some

CNT based composites which can be used for Airframe structure are: CNT/Epoxy, CNT/Polyimide, and CNT/PP

Fig: Nano-tube Fig: film Grapheme

Nano-clays reinforced Polymer Composites:

Properties of these composites are: Barrier Properties, Thermal and Flame Retardant.

Metal Nano-particles incorporated Composites:

The extra ordinary electrostatic discharge and electro-magnetic interference (EMI) shielding properties of these composites

make them the probable futuristic solution for making the structure which is resistant to lightning strikes.

2. NANO-COATINGS FOR AERO-ENGINE PARTS

The coatings are generally used for protecting the structures and surfaces of the aircraft from harsh environments. The stringent

requirements like resistance to extreme temperatures, extreme climates, corrosion, abrasion and wear of engine part shave

sparked an increased demand for more reliable high performance coatings. Some Nano-materials Coatings with improved high-

temperature properties may allow higher engine-operating temperatures and therefore improved performance in the future. In

particular, magnesium alloys, which are far lighter than steel or aluminium, are prone to corrosion, due to the high chemical



reactivity of magnesium. Coatings can help prevent corrosion, but the type, typically used contain chromium

complexes which are a highly toxic pollutant. Materials used for these novel anti-corrosion Nano-coatings include silicon and

boron oxides, and cobalt-phosphorous Nano-crystals. Nano-coatings are also now being used on turbine blades and other

mechanical components which have to withstand high temperatures and friction wear. Tribological coatings can drastically

lower the friction coefficient and improve resistance to wear - this greatly improves the efficiency of the engines.

Many Nano-structured and Nano-scale coating materials have been suggested as possible friction modifying agents, such as

carbides, nitrides, metals, and various ceramics few are as follows:

SiC Nano-particles in SiC-particle-reinforced alumina

TiN Nano-crystallites embedded in amorphous Si3N4 are used for Wear-resistant coatings.

The Nano-composite coatings made of crystalline Carbide, Diamond like Carbide and metal Di-Chalcogenide,

TiN are used for low friction and wear resistant applications of aircraft.

Nano-tube and Nano-particles (Nano-graphite, Nano-Aluminium) containing polymer coating are used for electrostatic

discharge, EMI shielding and low Friction applications of aircraft surfaces .

3. NANO-MATERIALS FOR AIRCRAFT ELECTRO-COMMUNICATION COMPONENTS CNTs have unique set of properties, including ballistic electron transport and a huge current carrying capacity,

which make them of great interest for future Nano-electronics. Magnetic Nano-particles (Iron oxide Nano-particles i.e. Fe2O3&Fe3O4)

Incorporated polymer films and composites can be used in various Data Storage Media.

Fig: Nano-particle

Ceramic Nano-particles like Barium Titanate, Barium Strontium Titanate are used for making Super Capacitors.

MEMS (Micro Electro Mechanical Systems) and NEMS (Nano Electro Mechanical Systems) offer the possibility of

developing a standard fuel management unit which controls the fuel control in aero-engines.

WHAT IS STEALTH TECHNOLOGY? Stealth technology is the use of special radar absorbent materials, flat angular surface design and other techniques to minimize

the amount of radiation reflected to a radar installation, causing an fighter aircraft or other vehicle to appear as a much smaller signal or not at all. Stealth means 'low observable'. Stealth technology was first used on aircraft such as the stealth bomb er due

to the reliance of air defense systems such as surface to air missiles on radar guidance. The very basic idea of Stealt h

Technology in the military is to 'blend' in with the background. The motive behind incorporating stealth technology in an

aircraft is not just to avoid missiles being fired at is but also to give total deniability to covert operations. This is very much

useful to strike targets where it is impossible to reach. Thus we can clearly say that the job of a stealth aircraft pilot is not to let

others know that he was ever there.

AIM OF STEALTH TECHNOLOGY

The idea is for the radar antenna to send out a burst of radio energy, which is then reflected back by any object it happens to

encounter. The radar antenna measures the time it takes for the reflection to arrive, and with that information can tell how far

away the object is. The metal body of an airplane is very good at reflecting radar signals, and this makes it easy to find an d track

airplanes with radar equipment. 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 rad ar



equipment. The airplane can be covered in materials that absorb radar signals. The goal of stealth techniques is to

bounce so little radar power back to its source that the target is nearly impossible to detect or track.

DETECTION TECHNIQUES

Following are techniques of detection for aircraft

RADAR

Heat detection

Turbulence detection

Visual detection

Radar is a system that allows the location, speed, and/or direction of a vehicle to be tracked. The word "radar" is actually an

acronym standing for Radio Detection And Ranging since the device uses radio waves to detect targets. Radar works by

sending out pulses of these electromagnetic waves and then "listening" for echoes bounced back by targets of interest. Even

though a radar may transmit megawatts of power in a single pulse, only a tiny fraction of that energy is typically bounced

back to be received by the radar antenna. The amount of power returned from a target to the transmitting radar depends on

four major factors:

1. The power transmitted in the direction of the target

2. The amount of power that impacts the target and is reflected back in the direction of the radar

3. The amount of reflected power that is intercepted by the radar antenna

4. The length of time in which the radar is pointed at the target.

STEALTH TECHNIQUES

Stealth Technology is used in the construction of mobile military systems such as aircrafts and ships to significantly reduce their

detection by enemy, primarily by an enemy RADAR. The way most airplane identification works is by constantly bombarding

airspace with a RADAR signal. Other methods focus on measuring acoustic (sound) disturbances, visual contact, and infrared

(heat) signatures. Stealth technologies work by reducing or eliminating these telltale signals. Panels on planes are angled s o that

radar is scattered and no signal returns. Planes are also covered in a layer o f absorbent materials that reduce any other signature

the plane might leave. Shape also has a lot to do with the `invisibility' of stealth planes. Extreme aerodynamics keeps air

turbulence to a minimum and cut down on flying noise. Special low-noise engines are contained inside the body of the plane.

Hot fumes are then capable of being mixed with cool air before leaving the plane. This fools heat sensors on the ground. This

also keeps heat seeking missiles from getting any sort of a lock on their targets.

Fig: Radar Detection Technique Fig: Stealth Technique

WHY STEALTH TECHNIQUE

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, s ome 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:

In addition, surfaces on a stealth aircraft can be treated so they absorb radar energy as well. The overall result is that a

stealth aircraft can have the radar signature of a small bird rather than an airplane. The only exception is when the plane

banks -- there will often be a moment when one of the panels of the plane will perfectly reflect a burst of radar energy back

to the antenna.

DISADVANTAGES OF NANO-MATERIALS

1. Instability of the particles - Retaining the active metal Nano-particles is highly challenging, as the kinetics associated

with Nano-materials is rapid. In order to retain

2. Nano-size of particles, they are encapsulated in some other matrix. Nano-materials are Thermodynamically meta-stable

and lie in the region of high-energy local-minima. Hence They are prone to attack and undergo transformation. These

include poor corrosion Resistance, high solubility, and phase change of Nano-materials. This leads to deterioration in

properties and retaining the structure becomes challenging.

3. Fine metal particles act as strong explosives owing to their high surface area coming in direct contact with oxygen.

Their exothermic combustion can easily cause explosion.

4. Impurity - Because Nano-particles are highly reactive, they inherently interact with impurities as well.

5. Difficulty in synthesis, isolation and application - It is extremely hard to retain the size of Nano-particles once they are

synthesized in a solution. Hence, the Nano-materials have to be encapsulated in a bigger and stable molecule/material.

Hence free

6. Recycling and disposal - There are no hard-and-fast safe disposal policies evolved for Nano-materials. Issues of their

toxicity are still under question, and results of exposure experiments are not available. Hence the uncertainty associated

with effects of Nano-materials is yet to be assessed in order to develop their disposal policies.

DISADVANTAGES OF STEALTH TECHNOLOGY

Stealth technology has its own disadvantages like other technologies.

Stealth aircraft cannot fly as fast or is not maneuverable like conventional aircraft.

Another serious disadvantage with the stealth aircraft is the reduced amount of payload it can carry. As most of the

payload is carried internally in a stealth aircraft to reduce the radar signature, weapons can only occupy a less amount

of space internally. On the other hand a conventional aircraft can carry much more payload than any stealth aircraft of

its class.

CONCLUSION The above details shows that the potential of Nano-materials with Stealth Technology in Aviation (Defense) Sector. Using

Nano-technology with Stealth Technology in aviation gives the Low Observability with Light Weight, High Strength, High

Toughness, Corrosion Resistance, Easy Reparability & Reusability, Less Maintenance & Durability with increase in carrying

Pay load hence it becomes cheaper, safer and used for protecting to be the target than the conventional. These technology has

some drawback also but due to above reason it can be ignored.

AKNOWLEDGEMENTS I would like to thanks Late M. Nirmala (Administrator Ganesh Institute of Engineering, Chennai), E. Natarajan (Professor

Mechanical Engineering, Anna University, Chennai) Mr. Ramesh Chandra Lal Das and Mira Devi (parents) for their full

support for making this paper

REFERENCES 1. EPA Nanotechnology White Paper

2. http://www.nnin.org/nnin_edu.html

3. http://www.workingin-nanotechnology.com

4. www.totalairdominance.com

5. www.howstuffworks.com

a nanotechnology aircraft with stealth technology

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