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List Of Hydrodynamic Instabilities
This is a list of hydrodynamic and plasma instabilities named after people (eponymous instabilities). See also * Eponym * List of fluid flows named after people * Instability * Hydrodynamic stability * Scientific phenomena named after people References {{Reflist * Chandrashekhar, S., ''Hydrodynamic and Hydromagnetic Stability'', Dover Publications, New York (1981). * Philip Drazin, Drazin, P. G. and W. H. Reid, ''Hydrodynamic Stability'', Cambridge Univ. Press, London (1981). Plasma instabilities, Lists of eponyms, Hydrodynamic instabilities Fluid dynamics Fluid dynamic instabilities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benjamin–Feir Instability
In the fields of nonlinear optics and fluid dynamics, modulational instability or sideband instability is a phenomenon whereby deviations from a periodic waveform are reinforced by nonlinearity, leading to the generation of Frequency spectrum, spectral-sidebands and the eventual breakup of the waveform into a train of wave packet, pulses. It is widely believed that the phenomenon was first discovered − and modeled − for periodic surface gravity waves (Stokes waves) on deep water by T. Brooke Benjamin and Jim E. Feir, in 1967. Therefore, it is also known as the Benjamin−Feir instability. However, spatial modulation instability of high-power lasers in organic solvents was observed by Russian scientists N. F. Piliptetskii and A. R. Rustamov in 1965, and the mathematical derivation of modulation instability was published by V. I. Bespalov and V. I. Talanov in 1966. Modulation instability is a possible mechanism for the generation of rogue waves. Initial instability and gain Modu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kink Instability
A kink instability (also known as a kink oscillation or kink mode) is a current-driven plasma instability characterized by transverse displacements of a plasma column's cross-section from its center of mass without any change in the characteristics of the plasma. It typically develops in a thin plasma column carrying a strong axial current which exceeds the Kruskal–Shafranov limit and is sometimes known as the Kruskal–Shafranov (kink) instability, named after Martin David Kruskal and Vitaly Shafranov. The kink instability was first widely explored in fusion power Fusion power is a proposed form of power generation that would generate electricity by using heat from nuclear fusion reactions. In a fusion process, two lighter atomic nuclei combine to form a heavier nucleus, while releasing energy. Devices d ... machines with Z-pinch configurations in the 1950s. It is one of the common magnetohydrodynamic instability modes which can develop in a pinch plasma and is som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz (; ; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Association, the largest German association of research institutions, was named in his honour. In the fields of physiology and psychology, Helmholtz is known for his mathematics concerning the eye, theories of vision, ideas on the visual perception of space, colour vision research, the sensation of tone, perceptions of sound, and empiricism in the physiology of perception. In physics, he is known for his theories on the conservation of energy and on the electrical double layer, work in electrodynamics, chemical thermodynamics, and on a mechanical foundation of thermodynamics. Although credit is shared with Julius von Mayer, James Joule, and Daniel Bernoulli—among others—for the energy conservation principles that e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin (26 June 182417 December 1907), was a British mathematician, Mathematical physics, mathematical physicist and engineer. Born in Belfast, he was the Professor of Natural Philosophy (Glasgow), professor of Natural Philosophy at the University of Glasgow for 53 years, where he undertook significant research on the mathematical analysis of electricity, was instrumental in the formulation of the first and second laws of thermodynamics, and contributed significantly to unifying physics, which was then in its infancy of development as an emerging academic discipline. He received the Royal Society's Copley Medal in 1883 and served as its President of the Royal Society, president from 1890 to 1895. In 1892, he became the first scientist to be elevated to the House of Lords. Absolute temperatures are stated in units of kelvin in Lord Kelvin's honour. While the existence of a coldest possible temperature, absolute zero, was known before his work, Kelvin d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin–Helmholtz Instability
The Kelvin–Helmholtz instability (after Lord Kelvin and Hermann von Helmholtz) is a fluid instability that occurs when there is shear velocity, velocity shear in a single continuum mechanics, continuous fluid or a velocity difference across the interface between two fluids. Kelvin-Helmholtz instabilities are visible in the atmospheres of planets and moons, such as in List of cloud types, cloud formations on Earth or the Great Red Spot#Great Red Spot, Red Spot on Jupiter, and the Stellar atmosphere, atmospheres of the Sun and other stars. Theory overview and mathematical concepts Fluid dynamics predicts the onset of instability and transition to turbulent flow within fluids of different density, densities moving at different speeds. If surface tension is ignored, two fluids in parallel motion with different velocities and densities yield an interface that is unstable to short-wavelength perturbations for all speeds. However, surface tension is able to stabilize the short w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Jeans
Sir James Hopwood Jeans (11 September 1877 – 16 September 1946) was an English physicist, mathematician and an astronomer. He served as a secretary of the Royal Society from 1919 to 1929, and was the president of the Royal Astronomical Society from 1925 to 1927, and won its Gold Medal of the Royal Astronomical Society, Gold Medal. Early life Born in Ormskirk, Lancashire, the son of William Tulloch Jeans, a parliamentary correspondent and author. Jeans was educated at Merchant Taylors' School, Northwood, Merchant Taylors' School, Wilson's School, Wilson's Grammar School, Camberwell and Trinity College, Cambridge. As a gifted student, Jeans was counselled to take an aggressive approach to the Cambridge Mathematical Tripos competition: Career Jeans was elected Fellow of Trinity College in October 1901, and taught at Cambridge, but went to Princeton University in 1904 as a professor of applied mathematics. He returned to Cambridge in 1910. From 1923 to 1944 he was associated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeans Instability
The Jeans instability is a concept in astrophysics that describes an instability that leads to the gravitational collapse of a cloud of gas or dust. It causes the collapse of interstellar gas clouds and subsequent star formation. It occurs when the internal gas pressure is not strong enough to prevent the gravitational collapse of a region filled with matter. It is named after James Jeans. For stability, the cloud must be in hydrostatic equilibrium, which in case of a spherical cloud translates to \frac=-\frac, where M_\text(r) is the enclosed mass, ''p'' is the pressure, \rho(r) is the density of the gas (at radius ''r''), ''G'' is the gravitational constant, and ''r'' is the radius. The equilibrium is stable if small perturbations are damped and unstable if they are amplified. In general, the cloud is unstable if it is either very massive at a given temperature or very cool at a given mass; under these circumstances, the gas pressure gradient cannot overcome gravitational fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jørgen Holmboe
Jørgen Holmboe (November 8, 1902 – October 29, 1979) was a Norwegian-American meteorologist. Life and career Jørgen Holmboe was born near Hammerfest, Norway, on an island a short distance from the northernmost point in Norway. He was the son of priest Leonhard Christian Borchgrevink Holmboe, Jr. and his wife Thea Louise Schetelig. He had several brothers and sisters. His great-grandfather Leonhard Christian Borchgrevink Holmboe was a priest and national politician.Norwegian He received his early education from his father, who was a minister, attended secondary school in Tromsø, and took his university entrance examinations in Bodø. He entered the University of Oslo in 1922. In 1925, he was appointed research assistant to Professor Vilhelm Bjerknes, who had moved from Bergen where as founding director of the Geophysical Institute he had led development of the Bergen School of Meteorology. In 1930, he passed his Candidate Real examinations and took a position as met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holmboe Instability
Holmboe is a Scandinavian surname. Notable people with the surname include: Norwegian family * Jens Holmboe (bailiff) (1752–1804), Norwegian bailiff * Even Hammer Holmboe (1792–1859), Norwegian politician, child of Jens Holmboe * Hans Holmboe (1798–1868), Norwegian educator and politician, child of Jens Holmboe * Leonhard Christian Borchgrevink Holmboe (1802–1887), Norwegian priest and politician, child of Jens Holmboe * Jens Holmboe (politician) (1821–1891), Norwegian politician, grandchild of Jens Holmboe * Conrad Holmboe (1828–1923), Norwegian businessman, grandchild of Jens Holmboe * Johan Henrik Rye Holmboe (1863–1933), Norwegian politician, great-grandchild of Jens Holmboe * Thorolf Holmboe (1866–1935), Norwegian painter, great-grandchild of Jens Holmboe * Cornelius Holmboe (1881–1947), Norwegian politician, great-grandchild of Jens Holmboe * Carl Fredrik Holmboe (1882-1960), Norwegian engineer, great-grandchild of Jens Holmboe * Joachim Holmboe R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boundary Layer
In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a Boundary (thermodynamic), bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces a No-slip condition, no-slip boundary condition (zero velocity at the wall). The flow velocity then monotonically increases above the surface until it returns to the bulk flow velocity. The thin layer consisting of fluid whose velocity has not yet returned to the bulk flow velocity is called the velocity boundary layer. The air next to a human is heated, resulting in gravity-induced convective airflow, which results in both a velocity and thermal boundary layer. A breeze disrupts the boundary layer, and hair and clothing protect it, making the human feel cooler or warmer. On an aircraft wing, the velocity boundary layer is the part of the flow close to the wing, where viscosity, viscous forces distort the surrounding non-viscous flow. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Görtler Vortices
In fluid dynamics, Görtler vortices are secondary flows that appear in a boundary layer flow along a concave wall. If the boundary layer is thin compared to the radius of curvature of the wall, the pressure remains constant across the boundary layer. On the other hand, if the boundary layer thickness is comparable to the radius of curvature, the centrifugal action creates a pressure variation across the boundary layer. This leads to the centrifugal instability (Görtler instability) of the boundary layer and consequent formation of Görtler vortices. These phenomena are named after mathematician . Görtler number The onset of Görtler vortices can be predicted using the dimensionless number called Görtler number (G). It is the ratio of centrifugal effects to the viscous effects in the boundary layer and is defined as : \mathrm = \frac \left( \frac \right)^ where : U_e = external velocity : \theta = momentum thickness : \nu = kinematic viscosity Viscosity is a measure of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
