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Supercavitating Torpedoes
Supercavitation is the use of a cavitation bubble to reduce skin friction drag on a submerged object and enable high speeds. Applications include torpedoes and propellers, but in theory, the technique could be extended to an entire underwater vessel. Physical principle Cavitation is the formation of vapour bubbles in liquid caused by flow around an object. Bubbles form when water accelerates around sharp corners and the pressure drops below the vapour pressure. Pressure increases upon deceleration, and the water generally reabsorbs the vapour; however, vapour bubbles can implode and apply small concentrated impulses that may damage surfaces like ship propellers and pump impellers. The potential for vapour bubbles to form in a liquid is given by the nondimensional cavitation number. It equals local pressure minus vapour pressure, divided by dynamic pressure. At increasing depths (or pressures in piping), the potential for cavitation is lower because the difference between local ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of its active battle fleet alone exceeding the next 13 navies combined, including 11 allies or partner nations of the United States as of 2015. It has the highest combined battle fleet tonnage (4,635,628 tonnes as of 2019) and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction, and five other carriers planned. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the United States Navy is the third largest of the United States military service branches in terms of personnel. It has 290 deployable combat vessels and more than 2,623 operational aircraft . The United States Navy traces its origins to the Continental Navy, which was established during the American Revo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregory Sancoff
Gregory may refer to: People and fictional characters * Gregory (given name), including a list of people and fictional characters with the given name * Gregory (surname), a surname Places Australia *Gregory, Queensland, a town in the Shire of Burke **Electoral district of Gregory, Queensland, Australia *Gregory, Western Australia. United States *Gregory, South Dakota *Gregory, Tennessee *Gregory, Texas Outer space *Gregory (lunar crater) *Gregory (crater on Venus) Other uses * "Gregory" (''The Americans''), the third episode of the first season of the television series ''The Americans'' See also * Greg (other) * Greggory * Gregoire (other) * Gregor (other) * Gregores (other) * Gregorian (other) * Gregory County (other) * Gregory Highway, Queensland * Gregory National Park, Northern Territory * Gregory River in the Shire of Burke, Queensland * Justice Gregory (other) Justice Gregory may refer to: * George G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juliet Marine Systems Ghost
Juliet Marine Systems ''Ghost'' is an advanced super-cavitating stealth ship that can reduce hull friction to 1/900th that of conventional watercraft. It was developed to provide superior protection and capabilities for United States military personnel. It was designed, developed, and built by the private American company Juliet Marine Systems. History Inventor Gregory Sancoff had decided to focus on small watercraft following the attack on USS ''Cole'' in 2000, after which he recalled saying: "Some yahoo terrorists in a cheap little boat and $500 worth of explosives can kill 17 sailors on a billion-dollar ship?" He also came across a 630-page United States Navy report on an exercise called Juliet, where the Navy attacked an enemy force of small, high-speed boats; after two days, the Navy had suffered over 20,000 simulated casualties. Sancoff gathered information on marine technology, including hydroplane racing boats and high-speed super-cavitating torpedoes. In 2007, Sanco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Dynamics Electric Boat
General Dynamics Electric Boat (GDEB) is a subsidiary of General Dynamics Corporation. It has been the primary builder of submarines for the United States Navy for more than 100 years. The company's main facilities are a shipyard in Groton, Connecticut, a hull-fabrication and outfitting facility in Quonset Point, Rhode Island, and a design and engineering facility in New London, Connecticut. History The company was founded in 1899 by Isaac Rice as the Electric Boat Company to build John Philip Holland's submersible ship designs, which were developed at Lewis Nixon's Crescent Shipyard in Elizabeth, New Jersey. ''Holland VI'' was the first submarine that this shipyard built, which became when it was commissioned into the United States Navy on April 11, 1900—the first submarine to be officially commissioned. The success of ''Holland VI'' created a demand for follow-up models (A class or ) that began with the prototype submersible ''Fulton'' built at Electric Boat. Some foreig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Littoral (military)
In military and naval warfare, littoral warfare is operations in and around the littoral zone, within a certain distance of shore, including surveillance, mine-clearing and support for landing operations and other types of combat shifting from water to ground, and back. Definition Littoral warfare is warfare in and around the littoral zone. History Littoral warfare has been conducted almost as long as human societies have been conducting warfare. In the 21st century the United States Marine Corps re-emphasized littoral warfare. See also * Amphibious warfare * Littoral combat ship The littoral combat ship (LCS) is either of two classes of relatively small surface vessels designed for operations near shore by the United States Navy. It was "envisioned to be a networked, agile, stealthy surface combatant capable of defeat ... References Combat {{mil-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DARPA
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Advanced Research Projects Agency (ARPA), the agency was created on February 7, 1958, by President Dwight D. Eisenhower in response to the Soviet Union, Soviet launching of Sputnik 1 in 1957. By collaborating with academia, industry, and government partners, DARPA formulates and executes research and development projects to expand the frontiers of technology and science, often beyond immediate U.S. military requirements.Dwight D. Eisenhower and Science & Technology, (2008). Dwight D. Eisenhower Memorial CommissionSource ''The Economist'' has called DARPA the agency "that shaped the modern world," and pointed out that "Moderna COVID-19 vaccine, Moderna's COVID-19 vaccine sits alongside weather satellites, Global Positioning System, GPS, Unmann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sergey Lavrov
Sergey Viktorovich Lavrov (russian: Сергей Викторович Лавров, ; born 21 March 1950) is a Russian diplomat and politician who has served as the Minister of Foreign Affairs (Russia), Foreign Minister of Russia since 2004. Lavrov served as the Permanent Representative of Russia to the United Nations from 1994 to 2004. Early life and education Lavrov was born on 21 March 1950 in Moscow, to an Armenians in Tbilisi, Armenian father from Tbilisi, Georgian Soviet Socialist Republic, Georgian SSR, and a Russians, Russian mother from Noginsk, Russian Socialist Federative Soviet Republic, Russian SFSR. His father's surname was originally Kalantaryan. His mother worked in the Soviet Ministry for Foreign Trade. Lavrov graduated from high school with a silver medal. Since his favorite class was physics, he planned to enter either the Moscow Engineering Physics Institute (National Research Nuclear University), National Research Nuclear University or the Moscow Institute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoot (torpedo)
The Hoot ( fa, حوت; ''Whale'') is an Iranian supercavitation torpedo claimed to travel at approximately , several times faster than a conventional torpedo. It was claimed to have been successfully test-fired from a surface ship against a dummy submarine during the Iranian military exercise "Great Prophet" () on 2 April 2006 and 3 April 2006. Iran test-fired the torpedo within its territorial waters in the Strait of Hormuz in May 2017. The official Iranian news agency IRNA claims the torpedo was produced and developed by the Islamic Revolutionary Guard Corps (). Most military and industry analysts have concluded that the Hoot is reverse engineered from the Russian VA-111 Shkval supercavitation torpedo which travels at the same speed. See also * List of supercavitating torpedoes A supercavitating torpedo is a torpedo using the effect of supercavitation to create a bubble around the torpedo to move at high velocity under water. The following is a list of supercavitating torpedoes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmenistan to the north, by Afghanistan and Pakistan to the east, and by the Gulf of Oman and the Persian Gulf to the south. It covers an area of , making it the 17th-largest country. Iran has a population of 86 million, making it the 17th-most populous country in the world, and the second-largest in the Middle East. Its largest cities, in descending order, are the capital Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz. The country is home to one of the world's oldest civilizations, beginning with the formation of the Elamite kingdoms in the fourth millennium BC. It was first unified by the Medes, an ancient Iranian people, in the seventh century BC, and reached its territorial height in the sixth century BC, when Cyrus the Great fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northrop Grumman
Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military technology providers. The firm ranks on the 2022 ''Fortune'' 500 list of America's largest corporations. Northrop Grumman and its industry partners have won the Collier Trophy eight times, most recently for developing the X-47B, the first unmanned, autonomous air system to operate from an aircraft carrier. Northrop Grumman currently leads the development of the B-21 Raider, a long-range, stealth strategic bomber that can drop conventional and nuclear weapons; it will replace Northrop's own B-2 Spirit, the world's only known stealth bomber. Among its other current projects are development and production of the James Webb Space Telescope, an orbiting observatory launched in 2021, and production of the solid rocket boosters for NASA's Space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell AH-1 Cobra
The Bell AH-1 Cobra is a single-engined attack helicopter developed and manufactured by the American rotorcraft manufacturer Bell Helicopter. A member of the prolific Huey family, the AH-1 is also referred to as the HueyCobra or Snake. The AH-1 was rapidly developed as an interim gunship in response to the United States Army's needs in the Vietnam War. It used the same engine, transmission and rotor system of the Bell UH-1 Iroquois, which had already proven itself to be a capable platform during the conflict, but paired it with a redesigned narrow fuselage among other features. The original AH-1, being a dedicated attack helicopter, came equipped with stub wings for various weapons, a chin-mounted gun turret, and an armored tandem cockpit, from which its was operated by a pilot and gunner. Its design was shaped to fulfil a need for a dedicated armed escort for transport helicopter, giving the latter greater survivability in contested environments. On 7 September 1965, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
