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Fluid Hammer
Hydraulic shock ( colloquial: water hammer; fluid hammer) is a pressure surge or wave caused when a fluid in motion, usually a liquid but sometimes also a gas is forced to stop or change direction suddenly; a momentum change. This phenomenon commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. This pressure wave can cause major problems, from noise and vibration to pipe rupture or collapse. It is possible to reduce the effects of the water hammer pulses with accumulators, expansion tanks, surge tanks, blowoff valves, and other features. The effects can be avoided by ensuring that no valves will close too quickly with significant flow, but there are many situations that can cause the effect. Rough calculations can be made using the Zhukovsky (Joukowsky) equation, or more accurate ones using the method of characteristics. History In the 1st century B.C., Marcus Vitruvius Pollio described the effect of w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Whitehurst
John Whitehurst FRS (10 April 1713 – 18 February 1788), born in Cheshire, England, was a clockmaker and scientist, and made significant early contributions to geology. He was an influential member of the Lunar Society. Life and work Whitehurst was born in Congleton, Cheshire, to a clockmaker, the elder John Whitehurst. Receiving only a slight formal education, the younger Whitehurst was taught clockmaking by his father, who also encouraged the boy's pursuit of knowledge. In 1734, at the age of twenty-one, Whitehurst visited Dublin to inspect a clock of curious construction of which he had heard. Career About 1736, Whitehurst entered into business for himself at Derby, where he soon obtained great employment, distinguishing himself by constructing several ingenious pieces of mechanism. Besides other works, he made the clock for the town hall, and on 6 September 1737, he was enrolled as a burgess in reward. He also made thermometers, barometers, and other philosophical in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Damper
A damper is a device that deadens, restrains, or depresses. It may refer to: Music * Damper pedal, a device that mutes musical tones, particularly in stringed instruments * A mute for various brass instruments Structure * Damper (flow), a mechanical device in a duct or chimney that regulates airflow * Stockbridge damper, used to suppress wind-induced vibrations on taut cables * Tuned mass damper, a device mounted in structures to prevent discomfort, damage or structural failure by vibration Other uses * Damper (food), a bread of the Australian Outback * Dashpot, a type of hydraulic or mechanical damper * Shock absorber A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most sh ... (British or technical use: ''damper''), a mechanical device designed to dissipate kinetic energy * An item of bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumbing
Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, ''plumbum'', as the first effective pipes used in the Roman era were lead pipes. In the developed world, plumbing infrastructure is critical to public health and sanitation. Boilermakers and pipefitters are not plumbers although they work with piping as part of their trade and their work can include some plumbing. History Plumbing originated during ancient civilizations, as they developed public baths and needed to provide potable water and wastewater removal for larger numbers of people. The Mesopotamians introduced the world to clay sewer pipes around 4000 BCE, with the earliest examples found i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorenzo Allievi
Lorenzo Allievi (November 18, 1856 – October 30, 1941) was an Italian engineer known for being one of the first to explain the water hammer problem.Kaveh Hariri Asli, Faig Bakhman Ogli Naghiyev, Reza Khodaparast Haghi, Hossien Hariri Asli, Advances in Control and Automation of Water Systems, CRC Press - 2012, page 2 Biography Allievi was born in Milan but moved with his family to Rome in 1871. There he graduated in 1879. He worked in Naples from 1893 to 1901 as CEO of ''Rinascimento di Napoli''. Then he came back to the Rome area and started working in the Terni steel/chemical/hydroelectric industrial district. In August 1902, when maintenance was being carried out on the hydroelectrical power plant of Papigno (Terni), the closure of a water pipe caused its explosion and great damage to the plant. Allievi investigated the problem immediately thereafter and published his fundamental study on the water hammer problem the same year. He continued to study this problem in the fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Palmer Frizell
Joseph Frizell (13 March 1832 – 4 May 1910) was an American engineer. He is notable for having independently derived the fundamental equations to describe the velocity of a shock wave (Water hammer equations) in 1898, and for his book Water-Power published in 1901. Water-power was the first practical book on hydraulics Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ... in the USA. This was a major milestone in propagation of engineering knowledge in USA, as Schutze wrote ″As an hydraulic engineer, Frizell was prominent, and his book, Waterpower, filled a definitive need in the technology of that day.″ Nevertheless, Frizell's description of the Water hammer was criticized by American contemporaries and his contribution to the field is under-recognised. References 1832 bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nikolay Yegorovich Zhukovsky
Nikolay Yegorovich Zhukovsky ( rus, Никола́й Его́рович Жуко́вский, p=ʐʊˈkofskʲɪj; – March 17, 1921) was a Russian scientist, mathematician and engineer, and a founding father of modern aero- and hydrodynamics. Whereas contemporary scientists scoffed at the idea of human flight, Zhukovsky was the first to undertake the study of airflow. He is often called the ''Father of Russian Aviation''. The Joukowsky transform is named after him, while the fundamental aerodynamical theorem, the Kutta–Joukowski theorem, is named after both him and German mathematician Martin Kutta. Life Zhukovsky was born in the village of Orekhovo, Vladimir Governorate, Russian Empire. In 1868, he graduated from Moscow University where he studied under August Davidov. From 1872, he was a professor at the Imperial Technical School. In 1904, he established the world's first Aerodynamic Institute in Kachino near Moscow. He was influenced by both Ernst Mach and his son ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Von Kries
Johannes Adolf von Kries (6 October 1853 – 30 December 1928) was a German physiological psychologist who formulated the modern “duplicity” or “duplexity” theory of vision mediated by rod cells at low light levels and three types of cone cells at higher light levels. He made important contributions in the field of haemodynamics. In addition, von Kries was a significant theorist of the foundations of probability. Biography When von Kries was at Freiburg (1880–1924), he was called to succeed Professor Emil Du Bois-Reymond as chair of physiology at the University of Berlin, but he declined. Von Kries has been called Helmholtz's "greatest German disciple". Works “Über den Druck in den Blutcapillaren der menschlichen Haut” ''Arbeiten aus der Physiologischen Anstalt zu Leipzig'' p 69-80 (1875). “Die Zeitdauer einfachster psychischer Vorgänge”with Felix Auerbach. ''Archiv für Physiologie'' p 297-378 (1877). * “Über die Bestimmung des Mitteldruckes durch d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Young (scientist)
Thomas Young FRS (13 June 177310 May 1829) was a British polymath who made notable contributions to the fields of vision, light, solid mechanics, energy, physiology, language, musical harmony, and Egyptology. He was instrumental in the decipherment of Egyptian hieroglyphs, specifically the Rosetta Stone. Young has been described as "The Last Man Who Knew Everything". His work influenced that of William Herschel, Hermann von Helmholtz, James Clerk Maxwell, and Albert Einstein. Young is credited with establishing the wave theory of light, in contrast to the particle theory of Isaac Newton. Young's work was subsequently supported by the work of Augustin-Jean Fresnel. Personal life Young belonged to a Quaker family of Milverton, Somerset, where he was born in 1773, the eldest of ten children. At the age of fourteen Young had learned Greek and Latin. Young began to study medicine in London at St Bartholomew's Hospital in 1792, moved to the University of Edinburgh Medical School i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Hydromechanics Research Association
The British Hydromechanics Research Association is a former government research association that supplies consulting engineering over fluid dynamics. History It was formed on 20 September 1947 in Essex, under the Companies Act 1929 It had moved to Bedfordshire by the 1960s. In the 1970s it was known as BHRA Fluid Engineering. Next door was the National Centre for Materials Handling, set up by the Ministry of Technology (MinTech), later known as the National Materials Handling Centre. On 16 October 1989 it became a private consultancy. Fluid engineering The BHRA conducted most of the research for the aerodynamics of British power station infrastructure in the 1960s, such as cooling towers. In 1966 it designed an early Thames flood barrier. Computational fluid dynamics It developed early CFD software. Visits On Tuesday 21 June 1966, the new Bedfordshire laboratories were opened by Duke of Edinburgh.''Times'' Saturday 18 June 1966, page 15 Structure The organisation, Framat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carlo Alberto Castigliano
Carlo Alberto Castigliano (9 November 1847, in Asti – 25 October 1884, in Milan) was an Italian mathematician and physicist known for Castigliano's method for determining displacements in a linear-elastic system based on the partial derivatives of strain energy. Alberto Castigliano moved from the region of his birth, Piedmont in northwestern Italy, to the Technical Institute of Terni (in Umbria) in 1866. After four years in Terni Terni ( , ; lat, Interamna (Nahars)) is a city in the southern portion of the region of Umbria in central Italy. It is near the border with Lazio. The city is the capital of the province of Terni, located in the plain of the Nera river. It is ..., Castigliano moved north again, this time to become a student at the Polytechnic of Turin. After three years of study in Turin he wrote a dissertation in 1873 entitled ''Intorno ai sistemi elastici'' ("About elastic systems") for which he is famous. In his dissertation there appears a theorem which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
