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US-Made Launch System For Indian Aircraft Carrier Possible: Indian Navy Chief

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US-Made Launch System For Indian Aircraft Carrier Possible: Indian Navy Chief

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The Indian Navy’s second indigenous aircraft carrier (IAC 2), to be locally built, could a have US-developed electromagnetic aircraft launch system (EMALS) as one of the subsystems, Admiral Robin Dhowan, the chief of naval staff (CNS) said this at the press conference in Delhi today.

Elaborating on the point, the CNS said that the request for proposals (RFP)s for the sub-systems ranging from propulsion to types of aircraft to be carried aboard the IAC 2 will be issued at the “right time.”

Dhowan, however, clarified keeping in mind the mantra of ‘Make in India,’ the aircraft carrier will be mostly indigenous.

The navy is also planning to look at the option of E2C Hawkeye carrier-capable airborne warning aircraft of US manufacture, he said.

The IAC 2 carrier is at a concept development stage and the US government has expressed interest in partnering India in developing specific systems and sub systems for the craft including the EMALS. An Indian team had visited certain US Navy ship building contractors earlier this year to learn about their carrier programs.

India is also being courted by Russia both for helping it build the carrier as well supply carrier-borne aircraft and helicopters.
 
we should go for 100 K ton plus carrier !
 
The energy stored is in the form of charge stored in a capacitor. The main challenge for EM catapult is to generate an extremely high amperage current. This is done by storing a huge amount of charge in capacitors, and discharging them whenever needed. The engineering challenge is to design such high storing capacitors, which was solved by using a property that spinning metallic spheres, under the right boundary conditions, have enormous capacitance. A lot of the design issues and their solutions are highly classified, but this is the general concept.

Source: Lets just say I have some working knowledge in physics.

I do not believe that is how the EMALS work.

The electrical energy is stored as Kinetic energy using a Fly Wheel i.e. a Mechanical Capacitor.

These are even available commercially nowadays, see eg. below,

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flywheel-energy-storage-system-6-638.jpg

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Energy stored in this Flywheel is converted into Electrical energy using Cyclo-converters similar to one's used in Wind Mills.

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This is then converted to DC Current,

Fig%202.3%20Common-neutral%20half-bridge%20ac-dc-ac%20converter.gif


And this DC current is used to power the EMALS which is nothing but a Linear Motor. This concept is similar to one a Magnetic Train use or one a Rail Gun use.


burrito-rail-gun-launch.gif


EMALS-490x367.jpg


Put the mall Together and we get an EMALS.


NAVY_EMALS_Components_lg.jpg
 
So to generate that much power for Emals.. the carrier have to be nuclear powered !! correct me if i am wrong ..
 
So to generate that much power for Emals.. the carrier have to be nuclear powered !! correct me if i am wrong ..

One measure of the efficiency of a generator or power plant that converts a fuel into heat and into electricity is the heat rate. Now the heat rate for Nuclear power plant and Fossil Fuel plant is almost same.

Primary difference is that the space for Storing nuclear material is fractional of that required for Fossil Fuel.


Aircraft Carrier has to carry fuel for Aircrafts (fixed wing & rotary) and for towing tractors.

Now in a Fossil Fuelled Ship it also has to allocate huge space for Diesel. In a place where space is premium like in an AC it is more practical to use Nuclear.

The drawback is that it is more difficult to design, maintain and is more Hazard prone and generally unsafe to be around. Radiation poisoning is a real danger.


Finally if the AC is going to use Electric Drive then you can be certain that it will be Nuclear powered.
 
I am not sure that any mechanical to electrical transducer could ever produce a 100-200 Ampere current.

"Energy stored in this Flywheel is converted into Electrical energy using Cyclo-converters similar to one's used in Wind Mills." -

I don't know if they made an enormous breakthrough in the last 5 years, or are revealing that to confuse people, but I worked for a guy who consulted for BAE at Caltech, and they used spinning metal spheres as capacitors, which generated the high amperage current on discharge. That is the only engineering solution to the requirement of high current sources on-board a tiny space like that of an aircraft carrier.

"This is then converted to DC Current"

I believe there is a huge problem in this part too. This works very well for normal industrial/household applications, but has significant energy loss problems for such high amperage currents.

Can you show me a BAE document/infograph that shows how their EM catapults work?

This is the photo of the flywheel Capacitor used to store energy that is used in the EMALS.

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This is another Industrial grade Flywheel Cpacitor,

Here an electric motor generator is connected to the flywheel allowing a DC voltage to be stored or recovered.

The electrical power is used to spin up the flywheel and when the power is turned off the flywheel continues to spin. To recover the power as electricity the motor generator is used to generate electricity thus slowing down the flywheel.

This model is tested for 530 kJ, 60 kW storage system and it weighs just 27 kg.

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I do not have any more details to share but the physics of it is rather well known.

Hope this helps,

The Energy Blog: About Flywheels

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Development of flywheels as a stand-alone energy storage unit for electrical power was made possible by advances in power electronics that allowed for the efficient voltage and frequency control of the power output regardless of the rotational rate of the flywheel. However size and resultant bearing stresses limited the speed and thus the amount of energy that could be stored. Subsequent advances, notably in carbon fiber materials and magnetic bearings allowed for higher energy densities.

Flywheels store energy proportionally to the mass of the rotor and to the square of its rotational surface speed. Therefore the best way to make it store more energy is to make it spin faster, not to make it heavier. It is important to understand that it is the surface speed that is important--not simply rpm's--so a smaller diameter flywheel, rotating much faster, can have the same energy level as a larger one, rotating slower.

Low speed metallic flywheels are used to smooth out the speed of engines, other rotating machines and in uninteruptable power supplies (UPS). The flywheel attached to the rotating shaft of a engine, moderates fluctuation in the shaft's speed by temporarily storing excess energy created during the power stroke and releasing the energy during the non-powered stroke. Low speed flywheel systems, designed for the UPS market with short spurts of power, generally have a heavy solid steel rotor and rotate at speeds less that 10,000 rpm and a mass upwards of 5,000 pounds.

The basic components of a high speed flywheel energy system are the rotor motor/generator bearing system, vacuum housing and power electronics. The rotor is the most important part of the system, as its design determines the amount of energy that can be stored.

High speed flywheels systems usually spin a lighter rotor at much higher speeds, potentially up to 100,000 rpm but generally in the 20,000 to 60,000 rpm range and a mass of 1,500 pounds or less. Because of the increased stresses at these speeds, high speed flyweel rotors are normally constructed from composite materials, such as fiberglass or carbon fibers impregnated with epoxy, wound into a thick cylinder. These materials are of lower density and higher strength than steel and provide the best combination of properties for this application.

To reduce losses in high speed systems magnetic bearings are used and the system is enclosed in a vacuum chamber to reduce aerodynamic drag. Magnetic bearings use magnetic forces to levitate the rotor and eliminate frictional losses from rolling elements and lubrication. These two features, although they reduce heat build up in the system, do not eliminated it. Unfortunately they also minimize the removal of heat from the system and some type of cooling is required.

Flywheels store energy through accelerating the rotor up to its operating speed and maintaining it at that speed by the addition of a small constant amount of energy input to overcome bearing friction and aerodynamic drag. When power is needed, the process is reversed by using the motor as a generator. It is possible to deeply discharge the flywheel without any damage to the unit because the energy is stored mechanically, not chemically. Thus nearly an infinite number of cycles, considering a 20-25 year life of the device, can be obtained.

Since the power and energy components are decoupled in flywheels these systems can be loosely classified into two categories optimized for either power or energy. Optimizing for power requires a greater emphasis on the motor/generator and power electronics, while optimizing for higher energy densities requires a larger, high speed rotor. As improved power electronics, vacuum housings, and magnetic bearings become more widespread, round-trip efficiencies of flywheel systems have improved and many current production models are in the 70% to 80% range, with some of the new designs even higher.

Pulse Power--Flywheels can be used to provide short burst of power in a variety of applications. Some include military applications, but much larger variety of applications can be found in a variety of industrial uses and engine starting in the transportation sector.
 
For such a high power requirement we need Nuclear Powered AC. Americans are ready to offer EMALS But not nuclear Technology. Also They are asking to sign Some foundation agreements to start sharing Technology which India can never sign with them
 
For such a high power requirement we need Nuclear Powered AC. Americans are ready to offer EMALS But not nuclear Technology. Also They are asking to sign Some foundation agreements to start sharing Technology which India can never sign with them
For EMALS India need the US no doubt about it, for the PWR India can probably get by without external assistance at this point- the work by the DAE on the Arihant's PWR and miniturisation process will be the foundation.

Intially I wasn't convinced that a carrier with EMALS would need to be nuclear powered (the Royal Navy explored this option for their conventionally powered QE Class) but having done reasearch into the topic it just makes sense. The amount of deisil fuel one would have to carry to power the extra generators and propel a 65,000 ton ship is simply not viable. As such nuclear power is the way to go but this would be a HUGE step for the IN to take and hence why they are taking their time with the decsion making.
 
@Helping Hand , I am not sure what you are objecting too.

The Motor generator is the one that reconverts the Kinetic Energy into an Electric Pulse. The second image is to provide an understanding as to how Fly wheel capacitances has real world application to make your understand its not something incredible.

Now based on the second eg., at 60KW , a pulse of 600 Volts will produce a current of 100 Amps. A series of pulse is what a linear motor would need to control the g on the catapult.

Finally the EMALS is made by General Atomic and not by BAE.

BAE has NO EMALS nor does UK have any carrier with EMALS.

What I have described is the general principle behind EMALS. It is indeed taken from open sources. What were you expecting ? Classified US Navy info ? :disagree:
 
In an actual EM catapult, no kinetic energy is converted to electromagnetic energy. Stored charge in a spinning metal capacitor is discharged to get 100A current. You are talking about hybrid cars, and civilian industrial technology, and I am sure you have no actual idea of how the EM catapult on aircraft carrier works, you are just guessing. Every one knows about the flywheel-energy-transfer...that is ancient technology compared to how an EM catapult works.

I am not sure why BAE was getting consultants to give them an idea about how to build their own EMALS, but we know they are heavily involved in the British carrier program, which was once considering an EMALS, and maybe wanted an idea of how things would work. I can not post links here, so this from defenseindustrialdaily may give us some idea why BAE might have also been interested in EMALS:

Back in March 2006, BAE Systems received a contract for “design and production of the 32 MJ Laboratory Launcher for the U.S. Navy.” Some hint of what they are talking about can be gleaned from the name. BAE isn’t the only firm that’s working on this program, which the US Navy sees as its gateway to a game-changing technology. The project is an electro-magnetic rail gun, which accelerates a projectile to incredibly high speeds without using explosives.

You may not have access to classified US Navy info, but I actually worked for the guy who is an expect on such things at Caltech. What you have been saying is the method everyone tried in the late 90s and early 2000s, but kinetic rotors were found to be incapable to produce currents required for EMALS, and the technology had to be changed. The problem isnt in physics, but in practical engineering.

Here is what the General Atomic's website says:

If you look at the EMALS Subsystems page, it says:
Energy Storage
The required energy for a launch is drawn from the energy storage devices during each two- to three-second launch. The energy storage devices are recharged from ship’s power between launches. In March 2008, the program celebrated a milestone with the successful completion of factory acceptance testing of the motor generator component of the EMALS energy storage subsystem (ESS). Four additional ESS systems support development testing and aircraft launches at the NAVAIR Lakehurst, N.J., culminating in aircraft launches at the test site.

They are very silent about how it actually stores energy, and it is understandable that they do not want anyone to have an idea about how they do it. But, they do give some clues on other pages, on just has to look around a bit deeper:

Technologies
Electromagnetic railguns are revolutionary weapons systems that use electricity instead of chemical propellants to fire projectiles at high speeds.

Electrical energy stored in capacitors in a pulsed power system creates magnetic fields that accelerate an armature between two rails to launch projectiles at 2 to 2.5 km/sec (Mach 6 to 7.5).

Also:

Pulsed Power Systems
GA-EMS designs and builds pulse power systems that drive railguns. Energy stored in capacitors is precisely switched and managed over the course of a few milliseconds in order to efficiently fire the railgun.

I hope this clears any misconceptions you had. GE says that it is the electrical energy stored in a capacitor which produces the current; it is not any mechanical energy stored in a flywheel. Flywheel concept is simply not practically feasible for such high power applications.

You are back to claiming stuff that is unsubstantiated and full of opinions / guesswork passing off as "facts".

You are free to claim fantastic hollow sphere lightning bolt theory and quite frankly I don't see the need to educate you. Enough to say that your claims were not proved, nor is your understanding of EMALS correct.

http://www.asee.org/documents/zones/zone1/2014/Student/PDFs/256.pdf

"Currently the United States Navy is working on a similar idea called the Electromagnetic Aircraft Launch System or EMALS which uses a similarly concept. For this project we will be using several capacitors wired in series to produce the necessary amount of current in our coil. Since the navy launches 45,000 lbs aircrafts the amount of energy storage that is needed is much larger and using lots of capacitors is impractical. The EMALS energy-storage subsystem draws power from the ship and stores it kinetically on rotors of four disk alternators. Each rotor can store more than 100 mega joules, and can be recharged within 45 seconds of a launch, which is much faster than steam catapults. This type of energy storage is ideal for this type of application but since we will be doing a small scale capacitors will do.

Another problem that is faced during projects like this is being able to complete a circuit with such high current. This same problem occurred when testing this project being that the SCR used could only handle 35A which is not nearly as much as the capacitors can discharge. Since the 1 SCR can’t handle the amount of current that we are trying to pass through it. In order to combat this issue the use of multiple SCR’s that are triggered at the same time which allows for the current to be divided through each SCR reducing the chance of a single one failing. Another challenge while using the SCR’s was that even if it can take the amount of current running through it the heat that it generates is very high which is why a heat skink was added to the original design."
 
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So you would believe some random paper than what General Electric say on their website? That "Electrical energy stored in capacitors in a pulsed power system creates magnetic fields that accelerate an armature between two rails to launch projectiles at 2 to 2.5 km/sec (Mach 6 to 7.5)." No problem with me.

"Fantastic hollow sphere lightning bold theory" It is neither fantastic, nor is bold, or a theory. That is how things actually work.

"I don't see the need to educate you" I have a PhD in physics, and I have spend a lot of time on free electron lasers and beam-like solutions to electromagnetic wave propagation. Based on your ability to continuously quote wrong information, I don't see how you could educate me.

For the Last time, there is a Capacitor, its an Electro-mechanical Capacitor. :hitwall:
 
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