Re: NOTICIAS SUB NUCLEAR BRASILEIRO
Enviado: Qua Abr 18, 2012 7:04 pm
Mais sobre AIP:
Air Independent Propulsion
A Must for Submarines
By Gulshan Luthra and Cmde Ranjit B Rai (Retd) Published: December 2011
New Delhi. Today, superior ship borne and airborne technologies of synthetic aperture, side looking and active electronic scanning array (AESA) radars, magnetic anomaly detectors (MAD), satellite imagery from space and heat detection from the air by helicopters, maritime reconnaissance aircraft and UAVs have taken long strides. The smallest of targets at sea at can be detected from long ranges.
Conventional submarines can operate under water only as long as there is charge in their batteries. At slow speed, the duration a submarine can stay underwater can be a day or two, but if the submarine moves at high speed to escape after an attack or go in for an attack, it will run out of battery power swiftly. For recharging, it will need to surface or come to a depth from where it can push a funnel pipe – snorkel – to suck air.
The name snorkel refers to an air intake just above the sea surface which enables a submerged submarine to draw air to run a diesel engine and to access atmospheric oxygen. Only the air intake pipe is visible while the submarine hull is invisible below the sea surface.
But the snorkel is susceptible of being located from ships, and particularly aircraft and satellites, thereby giving the position of the submarine.
The answer to this vulnerability of conventional submarines was the induction of nuclear propelled submarines which did not have to surface for months on end, but nuclear submarines are very expensive to build and maintain. Only five nations in the world, which are also nuclear weapon states, have the capability to build and operate nuclear submarines.
When India’s own home built submarine INS Airhant, presently undergoing harbour acceptance trials (HATS) at Vishakapatnam is commissioned, India will join this club as the sixth nation.
Brazil has a plan to build nuclear submarines with French ship and nuclear submarine builder DCNS’s help. Forty Brazilian engineers, architects and naval officers are undergoing training in France at the Centre Indret at Nantes to ultimately construct nuclear submarines in Brazil. Other submarine operating nations are looking to non-nuclear technology to enable submarines to stay under water for prolonged operations without surfacing.
DCNS, which supplied Agosta submarines to Pakistan and is building Indian Navy’s Scorpene submarines, invited Indian and some other foreign journalists to witness its facilities, including the construction of AIP systems. High-strength steel containers for Areva’s nuclear power plants for France and China were also being built there.
There was one AIP unit there, nearly built, possibly for a Pakistani Agosta.
AIP is a breakthrough technology for conventional submarines, enabling them to remain underwater three or four times a vessel’s standard capacity. It is a propulsion package technology given the generic name of Air Independent Propulsion.
The Indian Navy is working on a proposal to induct the AIP for the last two or three of its six Scorpene submarines being built by Mazagon Dock Ltd. (MDL) while the next lot of six more submarines will all be equipped with it.
Notably, a submarine is about stealth. It is a weapons platform not visible to the naked eye. AIP significantly improves stealth because it enables a submarine to generate electricity for services and battery charging and propulsion while completely submerged.
AIP systems are auxiliary, like a smaller hull inserted in the main body. They generate electricity, powering a submarine’s to operate and also generate oxygen, lighting and amenities for crew. Accordingly, they enable conventional diesel-electric submarines to remain submerged for two to three weeks at a time. Without AIP, diesel-electric submarines have to come up to snorkeling depths just below the surface or surface at shorter intervals so that the diesel engines can recharge their batteries. This significantly increases the risk of detection.
A submarine’s diesel engines can only be started once the snorkel has cleared the surface to take in oxygen in the fresh air. Snorkeling depth is about the same as periscope depth. AIP significantly improves stealth because it enables a submarine to generate electricity for services and battery charging and propulsion while completely submerged.
The development of AIP has taken time, and it was the Spanish scientist Narcís Monturiol i Estarriol who first thought of it in 1867. After that the Germans, British and Soviets worked on it. The latest French system, MESMA (Module d’Energie Sous- Marine Autonome) or Autonomous Underwater Energy Module, can be fitted on both the Agosta 90B and Scorpene class boats. Energy is produced onboard by burning ethanol and stored oxygen.
MESMA, or similar systems from some other countries, enable submarines to stay submerged for around three weeks. Their development has led to a paradigm shift in submarine warfare. In fact, this technology comes under the umbrella of the generic term, Revolution in Military Affairs (RMA), which has led to quantum jumps in the technologies and capabilities of platforms and weapon systems, and accordingly their deployment in conflicts and war.
One of the major challenges at sea is the identification of targets: friend or foe.
The advances made in detection of electronic transmissions (EW) and photography can be put through finger printing algorithms and even small contacts of submarine periscopes or a snorkel can be detected and identified. Therefore the paradigm shift in the auxiliary propulsion system of modern submarines with the development of AIP has made submarines even more versatile. They can approach enemy coasts undetected like nuclear submarines and conduct appropriate missile attacks.
MESMA can be retrofitted by fitting an additional hull section, called a plug, in the submarines.
The Pakistan Navy has already fitted MESMAs on two of its Agosta 90B Boats. The system was built and tested in France and then transported to Karachi.
Notably, as MESMA being an auxiliary system does not replace the main power units, or atmospheric-dependent propulsion. Nor does it give much speed to a boat but it does enable it to stay underwater for longer durations and move away after an attack to safer distances. A submarine is a sitting duck if detected, and aircraft like the Boeing P8-I which India is acquiring, are specifically designed to detect and hunt down submarines.
India’s Defence Research and Development Organisation (DRDO) is also now working on developing indigenous AIP technology at the Naval Material Research Laboratory (NMRL), Ambernath, by 2015.
Meanwhile, the Government has set aside $ 9 to 10 billion for six new generation AIP-equipped submarines under what is designated Project 75-I.
© India Strategic
Fonte: http://www.indiastrategic.in/topstories ... ulsion.htm
Air Independent Propulsion
A Must for Submarines
By Gulshan Luthra and Cmde Ranjit B Rai (Retd) Published: December 2011
New Delhi. Today, superior ship borne and airborne technologies of synthetic aperture, side looking and active electronic scanning array (AESA) radars, magnetic anomaly detectors (MAD), satellite imagery from space and heat detection from the air by helicopters, maritime reconnaissance aircraft and UAVs have taken long strides. The smallest of targets at sea at can be detected from long ranges.
Conventional submarines can operate under water only as long as there is charge in their batteries. At slow speed, the duration a submarine can stay underwater can be a day or two, but if the submarine moves at high speed to escape after an attack or go in for an attack, it will run out of battery power swiftly. For recharging, it will need to surface or come to a depth from where it can push a funnel pipe – snorkel – to suck air.
The name snorkel refers to an air intake just above the sea surface which enables a submerged submarine to draw air to run a diesel engine and to access atmospheric oxygen. Only the air intake pipe is visible while the submarine hull is invisible below the sea surface.
But the snorkel is susceptible of being located from ships, and particularly aircraft and satellites, thereby giving the position of the submarine.
The answer to this vulnerability of conventional submarines was the induction of nuclear propelled submarines which did not have to surface for months on end, but nuclear submarines are very expensive to build and maintain. Only five nations in the world, which are also nuclear weapon states, have the capability to build and operate nuclear submarines.
When India’s own home built submarine INS Airhant, presently undergoing harbour acceptance trials (HATS) at Vishakapatnam is commissioned, India will join this club as the sixth nation.
Brazil has a plan to build nuclear submarines with French ship and nuclear submarine builder DCNS’s help. Forty Brazilian engineers, architects and naval officers are undergoing training in France at the Centre Indret at Nantes to ultimately construct nuclear submarines in Brazil. Other submarine operating nations are looking to non-nuclear technology to enable submarines to stay under water for prolonged operations without surfacing.
DCNS, which supplied Agosta submarines to Pakistan and is building Indian Navy’s Scorpene submarines, invited Indian and some other foreign journalists to witness its facilities, including the construction of AIP systems. High-strength steel containers for Areva’s nuclear power plants for France and China were also being built there.
There was one AIP unit there, nearly built, possibly for a Pakistani Agosta.
AIP is a breakthrough technology for conventional submarines, enabling them to remain underwater three or four times a vessel’s standard capacity. It is a propulsion package technology given the generic name of Air Independent Propulsion.
The Indian Navy is working on a proposal to induct the AIP for the last two or three of its six Scorpene submarines being built by Mazagon Dock Ltd. (MDL) while the next lot of six more submarines will all be equipped with it.
Notably, a submarine is about stealth. It is a weapons platform not visible to the naked eye. AIP significantly improves stealth because it enables a submarine to generate electricity for services and battery charging and propulsion while completely submerged.
AIP systems are auxiliary, like a smaller hull inserted in the main body. They generate electricity, powering a submarine’s to operate and also generate oxygen, lighting and amenities for crew. Accordingly, they enable conventional diesel-electric submarines to remain submerged for two to three weeks at a time. Without AIP, diesel-electric submarines have to come up to snorkeling depths just below the surface or surface at shorter intervals so that the diesel engines can recharge their batteries. This significantly increases the risk of detection.
A submarine’s diesel engines can only be started once the snorkel has cleared the surface to take in oxygen in the fresh air. Snorkeling depth is about the same as periscope depth. AIP significantly improves stealth because it enables a submarine to generate electricity for services and battery charging and propulsion while completely submerged.
The development of AIP has taken time, and it was the Spanish scientist Narcís Monturiol i Estarriol who first thought of it in 1867. After that the Germans, British and Soviets worked on it. The latest French system, MESMA (Module d’Energie Sous- Marine Autonome) or Autonomous Underwater Energy Module, can be fitted on both the Agosta 90B and Scorpene class boats. Energy is produced onboard by burning ethanol and stored oxygen.
MESMA, or similar systems from some other countries, enable submarines to stay submerged for around three weeks. Their development has led to a paradigm shift in submarine warfare. In fact, this technology comes under the umbrella of the generic term, Revolution in Military Affairs (RMA), which has led to quantum jumps in the technologies and capabilities of platforms and weapon systems, and accordingly their deployment in conflicts and war.
One of the major challenges at sea is the identification of targets: friend or foe.
The advances made in detection of electronic transmissions (EW) and photography can be put through finger printing algorithms and even small contacts of submarine periscopes or a snorkel can be detected and identified. Therefore the paradigm shift in the auxiliary propulsion system of modern submarines with the development of AIP has made submarines even more versatile. They can approach enemy coasts undetected like nuclear submarines and conduct appropriate missile attacks.
MESMA can be retrofitted by fitting an additional hull section, called a plug, in the submarines.
The Pakistan Navy has already fitted MESMAs on two of its Agosta 90B Boats. The system was built and tested in France and then transported to Karachi.
Notably, as MESMA being an auxiliary system does not replace the main power units, or atmospheric-dependent propulsion. Nor does it give much speed to a boat but it does enable it to stay underwater for longer durations and move away after an attack to safer distances. A submarine is a sitting duck if detected, and aircraft like the Boeing P8-I which India is acquiring, are specifically designed to detect and hunt down submarines.
India’s Defence Research and Development Organisation (DRDO) is also now working on developing indigenous AIP technology at the Naval Material Research Laboratory (NMRL), Ambernath, by 2015.
Meanwhile, the Government has set aside $ 9 to 10 billion for six new generation AIP-equipped submarines under what is designated Project 75-I.
© India Strategic
Fonte: http://www.indiastrategic.in/topstories ... ulsion.htm
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