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Boundary layer

Index Boundary layer

In physics and fluid mechanics, a boundary layer is an important concept and refers to the layer of fluid in the immediate vicinity of a bounding surface where the effects of viscosity are significant. [1]

71 relations: A priori and a posteriori, Adverse pressure gradient, Aerodynamics, Aircraft, Airfoil, André Lévêque, Atmosphere of Earth, Bernoulli's principle, Blasius boundary layer, Boundary layer control, Boundary layer suction, Boundary layer thickness, Cartesian coordinate system, Coriolis force, Drag (physics), Ekman layer, Falkner–Skan boundary layer, Flow separation, Fluid, Fluid mechanics, Force, Fuselage, Gamma function, Glider (aircraft), Heat transfer, Heidelberg, Hendrik Tennekes, Hermann Schlichting, Incompressible flow, International Congress of Mathematicians, John L. Lumley, Keith Stewartson, Laminar flow, Laminar–turbulent transition, Law of the wall, Ludwig Prandtl, Mean, Navier–Stokes equations, Nikola Tesla, No-slip condition, Parasitic drag, Partial differential equation, Paul A. Libby, Paul Richard Heinrich Blasius, Peniche (fluid dynamics), Physics, Planetary boundary layer, Porosity, Prandtl number, Qian Xuesen, ..., Reynolds decomposition, Reynolds number, Richard von Mises, Scale analysis (mathematics), Shear stress, Similitude (model), Simple shear, Skin friction drag, Stokes boundary layer, Stream function, Tesla turbine, Theodore von Kármán, Thermal boundary layer thickness and shape, Thermodynamic system, Turbine, Turbulator, Turbulence, Turbulence modeling, Viscosity, Vortex generator, Wing. Expand index (21 more) »

A priori and a posteriori

The Latin phrases a priori ("from the earlier") and a posteriori ("from the latter") are philosophical terms of art popularized by Immanuel Kant's Critique of Pure Reason (first published in 1781, second edition in 1787), one of the most influential works in the history of philosophy.

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Adverse pressure gradient

In fluid dynamics, an adverse pressure gradient occurs when the static pressure increases in the direction of the flow.

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Aerodynamics, from Greek ἀήρ aer (air) + δυναμική (dynamics), is the study of the motion of air, particularly its interaction with a solid object, such as an airplane wing.

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An aircraft is a machine that is able to fly by gaining support from the air.

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An airfoil (American English) or aerofoil (British English) is the shape of a wing, blade (of a propeller, rotor, or turbine), or sail (as seen in cross-section).

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André Lévêque

André Marcel Lévêque (23 October 1896 - 1 March 1930) was a French engineer, famous for his work on heat transfer.

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Atmosphere of Earth

The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity.

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Bernoulli's principle

In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.

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Blasius boundary layer

In physics and fluid mechanics, a Blasius boundary layer (named after Paul Richard Heinrich Blasius) describes the steady two-dimensional laminar boundary layer that forms on a semi-infinite plate which is held parallel to a constant unidirectional flow.

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Boundary layer control

Boundary layer control refers to methods of controlling the behaviour of fluid flow boundary layers.

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Boundary layer suction

Boundary layer suction is a boundary layer control technique in which an air pump is used to extract the boundary layer at the wing or the inlet of an aircraft.

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Boundary layer thickness

This page describes some parameters used to characterize the properties of a boundary layer formed by fluid flow along a wall.

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Cartesian coordinate system

A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular directed lines, measured in the same unit of length.

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Coriolis force

In physics, the Coriolis force is an inertial force that acts on objects that are in motion relative to a rotating reference frame.

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Drag (physics)

In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.

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Ekman layer

The Ekman layer is the layer in a fluid where there is a force balance between pressure gradient force, Coriolis force and turbulent drag.

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Falkner–Skan boundary layer

In fluid dynamics, the Falkner–Skan boundary layer (named after V. M. Falkner and Sylvia W. Skan) describes the steady two-dimensional laminar boundary layer that forms on a wedge, i.e. flows in which the plate is not parallel to the flow.

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Flow separation

All solid objects traveling through a fluid (or alternatively a stationary object exposed to a moving fluid) acquire a boundary layer of fluid around them where viscous forces occur in the layer of fluid close to the solid surface.

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In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress.

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Fluid mechanics

Fluid mechanics is a branch of physics concerned with the mechanics of fluids (liquids, gases, and plasmas) and the forces on them.

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In physics, a force is any interaction that, when unopposed, will change the motion of an object.

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The fuselage (from the French fuselé "spindle-shaped") is an aircraft's main body section.

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Gamma function

In mathematics, the gamma function (represented by, the capital Greek alphabet letter gamma) is an extension of the factorial function, with its argument shifted down by 1, to real and complex numbers.

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Glider (aircraft)

A glider is a heavier-than-air aircraft that is supported in flight by the dynamic reaction of the air against its lifting surfaces, and whose free flight does not depend on an engine.

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Heat transfer

Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems.

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Heidelberg is a college town in Baden-Württemberg situated on the river Neckar in south-west Germany.

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Hendrik Tennekes

Hendrik (Henk) Tennekes (born December 13, 1936, Kampen) was the director of research at the Royal Dutch Meteorological Institute (Koninklijk Nederlands Meteorologisch Instituut, or KNMI), and was a Professor of Aeronautical Engineering at Pennsylvania State University.

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Hermann Schlichting

Hermann Schlichting (22 September 1907 – 15 June 1982) was a German fluid dynamics engineer.

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Incompressible flow

In fluid mechanics or more generally continuum mechanics, incompressible flow (isochoric flow) refers to a flow in which the material density is constant within a fluid parcel—an infinitesimal volume that moves with the flow velocity.

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International Congress of Mathematicians

The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics.

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John L. Lumley

John Leask Lumley (4 November 1930 in Detroit, Michigan – 30 May 2015 in Ithaca, New York) was an American professor mechanical engineering and aerospace engineering at Cornell University.

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Keith Stewartson

Keith Stewartson (20 September 1925 – 7 May 1983) was an English mathematician and fellow of the Royal Society.

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Laminar flow

In fluid dynamics, laminar flow (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption between the layers.

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Laminar–turbulent transition

The process of a laminar flow becoming turbulent is known as laminar–turbulent transition.

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Law of the wall

In fluid dynamics, the law of the wall states that the average velocity of a turbulent flow at a certain point is proportional to the logarithm of the distance from that point to the "wall", or the boundary of the fluid region.

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Ludwig Prandtl

Ludwig Prandtl (4 February 1875 – 15 August 1953) was a German engineer.

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In mathematics, mean has several different definitions depending on the context.

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Navier–Stokes equations

In physics, the Navier–Stokes equations, named after Claude-Louis Navier and George Gabriel Stokes, describe the motion of viscous fluid substances.

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Nikola Tesla

Nikola Tesla (Никола Тесла; 10 July 1856 – 7 January 1943) was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist who is best known for his contributions to the design of the modern alternating current (AC) electricity supply system.

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No-slip condition

In fluid dynamics, the no-slip condition for viscous fluids assumes that at a solid boundary, the fluid will have zero velocity relative to the boundary.

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Parasitic drag

Parasitic drag is drag that results when an object is moved through a fluid medium.

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Partial differential equation

In mathematics, a partial differential equation (PDE) is a differential equation that contains unknown multivariable functions and their partial derivatives.

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Paul A. Libby

Paul A Libby (born September 4, 1921) is an Emeritus Professor of Mechanical and Aerospace Engineering at the University of California, San Diego, a specialist in the field of Combustion and Aerospace Engineering.

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Paul Richard Heinrich Blasius

Paul Richard Heinrich Blasius (9 August 1883 – 24 April 1970) was a German fluid dynamics physicist.

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Peniche (fluid dynamics)

A peniche (or stand-off) is material inserted between a half-model, often of an airplane, and the wall of a wind tunnel.

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Physics (from knowledge of nature, from φύσις phýsis "nature") is the natural science that studies matterAt the start of The Feynman Lectures on Physics, Richard Feynman offers the atomic hypothesis as the single most prolific scientific concept: "If, in some cataclysm, all scientific knowledge were to be destroyed one sentence what statement would contain the most information in the fewest words? I believe it is that all things are made up of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another..." and its motion and behavior through space and time and that studies the related entities of energy and force."Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves."Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of the human intellect in its quest to understand our world and ourselves."Physics is an experimental science. Physicists observe the phenomena of nature and try to find patterns that relate these phenomena.""Physics is the study of your world and the world and universe around you." Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over the last two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the scientific revolution in the 17th century, these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy. Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

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Planetary boundary layer

In meteorology the planetary boundary layer (PBL), also known as the atmospheric boundary layer (ABL), is the lowest part of the atmosphere.

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Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%.

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Prandtl number

The Prandtl number (Pr) or Prandtl group is a dimensionless number, named after the German physicist Ludwig Prandtl, defined as the ratio of momentum diffusivity to thermal diffusivity.

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Qian Xuesen

Qian Xuesen, or Hsue-Shen Tsien (11 December 1911 – 31 October 2009), was a prominent Chinese aerodynamicist and cyberneticist who contributed to rocket science and established engineering cybernetics.

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Reynolds decomposition

In fluid dynamics and turbulence theory, Reynolds decomposition is a mathematical technique used to separate the expectation value of a quantity from its fluctuations.

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Reynolds number

The Reynolds number is an important dimensionless quantity in fluid mechanics used to help predict flow patterns in different fluid flow situations.

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Richard von Mises

Richard Edler von Mises (19 April 1883 – 14 July 1953) was a scientist and mathematician who worked on solid mechanics, fluid mechanics, aerodynamics, aeronautics, statistics and probability theory.

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Scale analysis (mathematics)

Scale analysis (or order-of-magnitude analysis) is a powerful tool used in the mathematical sciences for the simplification of equations with many terms.

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Shear stress

A shear stress, often denoted by (Greek: tau), is the component of stress coplanar with a material cross section.

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Similitude (model)

Similitude is a concept applicable to the testing of engineering models.

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Simple shear

Simple shear is a deformation in which parallel planes in a material remain parallel and maintain a constant distance, while translating relative to each other.

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Skin friction drag

Skin friction drag is a component of profile drag, which is resistant force exerted on an object moving in a fluid.

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Stokes boundary layer

In fluid dynamics, the Stokes boundary layer, or oscillatory boundary layer, refers to the boundary layer close to a solid wall in oscillatory flow of a viscous fluid.

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Stream function

The stream function is defined for incompressible (divergence-free) flows in two dimensions – as well as in three dimensions with axisymmetry.

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Tesla turbine

The Tesla turbine is a bladeless centripetal flow turbine patented by Nikola Tesla in 1913.

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Theodore von Kármán

Theodore von Kármán ((szőllőskislaki) Kármán Tódor; 11 May 1881 – 6 May 1963) was a Hungarian-American mathematician, aerospace engineer, and physicist who was active primarily in the fields of aeronautics and astronautics.

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Thermal boundary layer thickness and shape

This page describes some parameters used to characterize the properties of the thermal boundary layer formed by a heated (or cooled) fluid moving along a heated (or cooled) wall.

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Thermodynamic system

A thermodynamic system is the material and radiative content of a macroscopic volume in space, that can be adequately described by thermodynamic state variables such as temperature, entropy, internal energy, and pressure.

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A turbine (from the Latin turbo, a vortex, related to the Greek τύρβη, tyrbē, meaning "turbulence") is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work.

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A turbulator is a device that turns a laminar flow into a turbulent flow.

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In fluid dynamics, turbulence or turbulent flow is any pattern of fluid motion characterized by chaotic changes in pressure and flow velocity.

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Turbulence modeling

Turbulence modeling is the construction and use of a model to predict the effects of turbulence.

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The viscosity of a fluid is the measure of its resistance to gradual deformation by shear stress or tensile stress.

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Vortex generator

A vortex generator (VG) is an aerodynamic device, consisting of a small vane usually attached to a lifting surface (or airfoil, such as an aircraft wing) or a rotor blade of a wind turbine.

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A wing is a type of fin that produces lift, while moving through air or some other fluid.

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Boundary Layer, Boundary layer effect, Boundary layer flow, Boundary layer theory, Boundary layers, Boundary-layer, Convective boundary layer, Fluid boundary layer, Shear layers, Surface boundary layer, Turbulent boundary layer.


[1] https://en.wikipedia.org/wiki/Boundary_layer

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