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Stokes Boundary Layer
In fluid dynamics, Stokes problem also known as Stokes second problem or sometimes referred to as Stokes boundary layer or Oscillating boundary layer is a problem of determining the flow created by an oscillating solid surface, named after Sir George Stokes. This is considered one of the simplest unsteady problem that have exact solution for the Navier-Stokes equations. In turbulent flow, this is still named a Stokes boundary layer, but now one has to rely on experiments, numerical simulations or approximate methods in order to obtain useful information on the flow. Flow description Consider an infinitely long plate which is oscillating with a velocity U \cos \omega t in the x direction, which is located at y=0 in an infinite domain of fluid, where \omega is the frequency of the oscillations. The incompressible Navier-Stokes equations reduce to :\frac = \nu \frac where \nu is the kinematic viscosity. The pressure gradient does not enter into the problem. The initial, no-slip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stokes Boundary Layer
In fluid dynamics, Stokes problem also known as Stokes second problem or sometimes referred to as Stokes boundary layer or Oscillating boundary layer is a problem of determining the flow created by an oscillating solid surface, named after Sir George Stokes. This is considered one of the simplest unsteady problem that have exact solution for the Navier-Stokes equations. In turbulent flow, this is still named a Stokes boundary layer, but now one has to rely on experiments, numerical simulations or approximate methods in order to obtain useful information on the flow. Flow description Consider an infinitely long plate which is oscillating with a velocity U \cos \omega t in the x direction, which is located at y=0 in an infinite domain of fluid, where \omega is the frequency of the oscillations. The incompressible Navier-Stokes equations reduce to :\frac = \nu \frac where \nu is the kinematic viscosity. The pressure gradient does not enter into the problem. The initial, no-slip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Wave
In fluid dynamics, a wind wave, water wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result from the wind blowing over the water surface. The contact distance in the direction of the wind is known as the ''fetch''. Waves in the oceans can travel thousands of kilometers before reaching land. Wind waves on Earth range in size from small ripples, to waves over high, being limited by wind speed, duration, fetch, and water depth. When directly generated and affected by local wind, a wind wave system is called a wind sea. Wind waves will travel in a great circle route after being generated – curving slightly left in the southern hemisphere and slightly right in the northern hemisphere. After moving out of the area of fetch, wind waves are called '' swells'' and can travel thousands of kilometers. A noteworthy example of this is waves generated south of Tasmania during heavy winds that will travel across the Pacif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Couette Flow
In fluid dynamics, Couette flow is the flow of a viscous fluid in the space between two surfaces, one of which is moving tangentially relative to the other. The relative motion of the surfaces imposes a shear stress on the fluid and induces flow. Depending on the definition of the term, there may also be an applied pressure gradient in the flow direction. The Couette configuration models certain practical problems, like the Earth's mantle and atmosphere, and flow in lightly loaded journal bearings. It is also employed in viscometry and to demonstrate approximations of reversibility. It is named after Maurice Couette, a Professor of Physics at the French University of Angers in the late 19th century. Planar Couette flow Couette flow is frequently used in undergraduate physics and engineering courses to illustrate shear-driven fluid motion. A simple configuration corresponds to two infinite, parallel plates separated by a distance h; one plate translates with a constant rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin Functions
In applied mathematics, the Kelvin functions ber''ν''(''x'') and bei''ν''(''x'') are the real and imaginary parts, respectively, of :J_\nu \left (x e^ \right ),\, where ''x'' is real, and , is the ''ν''th order Bessel function of the first kind. Similarly, the functions kerν(''x'') and keiν(''x'') are the real and imaginary parts, respectively, of :K_\nu \left (x e^ \right ),\, where is the ''ν''th order modified Bessel function of the second kind. These functions are named after William Thomson, 1st Baron Kelvin. While the Kelvin functions are defined as the real and imaginary parts of Bessel functions with ''x'' taken to be real, the functions can be analytically continued for complex arguments With the exception of ber''n''(''x'') and bei''n''(''x'') for integral ''n'', the Kelvin functions have a branch point at ''x'' = 0. Below, is the gamma function and is the digamma function. ber(''x'') For integers ''n'', ber''n''(''x'') has the series expan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman Riley (professor)
Norman Riley is an Emeritus Professor of Applied Mathematics at the University of East Anglia in Norwich (UK). Biography Following High School education at Calder High School, Mytholmroyd he read Mathematics at Manchester University graduating with first class honours in 1956, followed by a PhD in 1959. Norman Riley served for one year as an Assistant Lecturer at Manchester University and then spent four years as a lecturer at Durham University before he joined the then new University of East Anglia in 1964, the year that saw the first significant intake of students to the university. Promotion to Reader in 1966 was followed by promotion to a Personal Chair in 1971. He retired in 1999. Married in 1959 he has one son and one daughter. Research contributions His research contributions in the field of fluid mechanics, over five decades, have included: unsteady flows with application to acoustic levitation and the loading on the submerged horizontal pontoons of tethered leg platf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philip Drazin
Philip Gerald Drazin (25 May 1934 – 10 January 2002) was a British mathematician and a leading international expert in fluid dynamics. He completed his PhD at the University of Cambridge under G. I. Taylor in 1958. He was awarded the Smith's Prize in 1957. After leaving Cambridge, he spent two years at MIT before moving to the University of Bristol, where he stayed and became a Professor until retiring in 1999. After retiring, he lectured at the University of Oxford and the University of Bath until his death in 2002. Drazin worked on hydrodynamic stability and the transition to turbulence. His 1974 paper ''On a model of instability of a slowly-varying flow'' introduced the concept of a global mode solution to a system of partial differential equations such as the Navier-Stokes equations. He also worked on solitons. In 1998 he was awarded the Symons Gold Medal of the Royal Meteorological Society. References External links Philip Gerald Drazinat the Mathematics Geneal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Waves
In fluid dynamics, a wind wave, water wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result from the wind blowing over the water surface. The contact distance in the direction of the wind is known as the ''fetch''. Waves in the oceans can travel thousands of kilometers before reaching land. Wind waves on Earth range in size from small ripples, to waves over high, being limited by wind speed, duration, fetch, and water depth. When directly generated and affected by local wind, a wind wave system is called a wind sea. Wind waves will travel in a great circle route after being generated – curving slightly left in the southern hemisphere and slightly right in the northern hemisphere. After moving out of the area of fetch, wind waves are called '' swells'' and can travel thousands of kilometers. A noteworthy example of this is waves generated south of Tasmania during heavy winds that will travel across the Pacif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Waves
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges. Acoustics Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an ''acoustician'', while someone working in the field of acoustical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Superposition
The superposition principle, also known as superposition property, states that, for all linear systems, the net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually. So that if input ''A'' produces response ''X'' and input ''B'' produces response ''Y'' then input (''A'' + ''B'') produces response (''X'' + ''Y''). A function F(x) that satisfies the superposition principle is called a linear function. Superposition can be defined by two simpler properties: additivity F(x_1+x_2)=F(x_1)+F(x_2) \, and homogeneity F(a x)=a F(x) \, for scalar . This principle has many applications in physics and engineering because many physical systems can be modeled as linear systems. For example, a beam can be modeled as a linear system where the input stimulus is the load on the beam and the output response is the deflection of the beam. The importance of linear systems is that they are easier to analyze mathematically; the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Far-field
The near field and far field are regions of the electromagnetic (EM) field around an object, such as a transmitting antenna, or the result of radiation scattering off an object. Non-radiative ''near-field'' behaviors dominate close to the antenna or scattering object, while electromagnetic radiation ''far-field'' behaviors dominate at greater distances. Far-field E (electric) and B (magnetic) field strength decreases as the distance from the source increases, resulting in an inverse-square law for the radiated ''power'' intensity of electromagnetic radiation. By contrast, near-field E and B strength decrease more rapidly with distance: the radiative field decreases by the inverse-distance squared, the reactive field by an inverse-cube law, resulting in a diminished power in the parts of the electric field by an inverse fourth-power and sixth-power, respectively. The rapid drop in power contained in the near-field ensures that effects due to the near-field essentially vanish a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stokes Boundary Layer Oscillating Flow
Stokes may refer to: People * Stokes (surname), a surname (including a list of people with the name) Science * Stokes (unit), a measure of viscosity * Stokes boundary layer * Stokes drift For a pure wave motion in fluid dynamics, the Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experien ... * Stokes flow * Stokes' law * Stokes' law of sound attenuation * Stokes line * Stokes number * Stokes parameters * Stokes radius * Stokes relations * Stokes shift * Stokes stream function * Stokes' theorem * Stokes wave * Campbell–Stokes recorder * Navier–Stokes equations Places Australia * Stokes, Queensland, a locality in the Shire of Carpentaria, Queensland, Australia * Stokes Bay (South Australia), a bay in South Australia * Stokes Bay, South Australia, a locality in South Australia * Stokes National Park, in the Goldfields-Esperanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chia-Shun Yih
Chia-Shun Yih (; July 25, 1918 – April 25, 1997) was the Stephen P. Timoshenko Distinguished University Professor Emeritus at the University of Michigan. He made many significant contributions to fluid mechanics. Yih was also a seal artist. Biography Yih was born on July 25, 1918, in Guiyang, Guizhou province of China. Yih received his junior middle school education in Zhenjiang, and entered Suzhou High School in 1934 in Suzhou, Jiangsu Province. In 1937, Yih entered the National Central University and studied civil engineering. Yih graduated in 1941 then did research at a hydrodynamics laboratory in Guanxian (or Guan County; 灌县; current Dujiangyan) of Sichuan province. Yih also worked in a bridge construction company in Guizhou. Later, Yih taught at Guizhou University. In 1945, Yih went to study at the University of Iowa in the United States, where he obtained his PhD in 1948. Yih served as a professor of the University of Michigan for most of his academic career. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
