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The flow field indicates a speed for every point in the room and at all times [first] (Generally a vector in a vector field), with which physical variables, such as material properties, force effects and interactions, are transported within a spatial area. Classification of the flow fields [ Edit | Edit the source text ] One differentiates In terms of time variability (flow types [2] ):stationary flow fields that have a vector field that is constant over time, which therefore only depends on the location and is usually relatively easy to model, or Intstationary flow fields that are time -dependent. With regard to the local variability:Homogeneous flow fields in which the speed (the vector field) is the same at all space points, and Inhomogenees, d. H. spatial not Constant flow fields in which the speed (the vector field) depends on the location. With regard to the dimensionality (flow groups [2] ):Flow fields that are essentially one -dimensional. They are the subject of electricity thread theory and hydraulics. level flow fields that are essentially two -dimensional, such as profile currents or magnetic fields around cylindrical stable magnets Spatial flow fields that need three or more room coordinates to describe their description. With regard to the analytical properties (flow classes [2] ):In source -free flow fields, the river is equal to the escaping river, field lines are literally infinite or end on the edge of the flow field, and there are no field lines that start or end in the flow field. Rotation -free flow fields can be clearly described as vortex -free; But it doesn’t mean the same thing. Rotation -free flow fields always have a potential, the gradient field of which results in the flow field. Flow fields can (almost all) be represented according to the Helmholtz theorem as a superposition of a rotary-free and a source-free (divergence-free) field. Rivers and river seals [ Edit | Edit the source text ] In a flow field, the mass current is occasionally interested, which indicates how much fluid mass per time span occurs over a defined area (flow measurement). The mass current is one River size . In general, a river indicates how much of a physical size per time span flows through a test area. Since in rivers in spatial areas primarily their Poetry Interested and rivers are described as most difficult to use surface integral, the river per area is primarily considered in flow fields, the river per area. Depending on the specific area of \u200b\u200bapplication, rivers and their dense z. B. act on electrical load carriers, liquids, gases or magnetic rivers. In homogeneous flow fields, the river distribution is constant in a certain space segment of the flow field. Only in this case is the density D {displaystyle D} of the field the simple quotient from river F {displaystyle F} and area A {displaystyle A} : Dhom= FA{Displaystyle d_ {text {homose}} = {frac {f}}}}}} . In inhomogeneous flow fields, the river density is different at each space point and the river is to be calculated as a derivation: Dinhom= dFdA{Displaystyle d_ {Text {inhom}} = {frac {df} {da}}} The river distributions can change in temporary flow fields. Visualization [ Edit | Edit the source text ] Flow fields can be illustrated with the help of field lines. The tangent on the field lines indicates the direction of the field at the respective contact point and the density of the field lines indicates the strength of the field. A distinction is made between electricity, string and rail lines in fluid mechanics, see #flow field in the mechanics. In electrodynamics, flow fields serve, among other things, to describe the spatial distribution of electrical currents, which is described by the power density. For example, the charge carrier current (electrons) in an electrical conductor (cable) results in a certain, generally not constant electricity density (power distribution). The current of load carriers places the electrical current I {displaystyle I} it, the linked density is the electrical power density J {DisplayStyle J} . Furthermore, a spatial distribution of electrical loads represents a flow field of the electrical river. Electricity corresponds to the distributed electrical loads (room loads) Q {displaystyle Q} , the associated river density is the electrical flux density D {displaystyle D} . One last example of a flow field in electrodynamics is the magnetic flow Phi {displaystyle Phi } mentioned. This is primarily caused by spatial distributed currents, charge carrier movements. The associated magnetic flux density B {displaystyle B} is given in Tesla. Quasistatic flow field [ Edit | Edit the source text ] Quasistatic flow fields occur in alternating current runners or something in impulse stream resistors, as long as there are no signs of power. Whether a flow field can be described as quasi -static or not depends on the arrangement and the change of change in the variable tension driving the line current. Therefore, the same applies to the quasi -static flow of flow without power displacement as for a static flow field. The flow mechanics treats flowing liquids and gases, the flow of which occurs through pressure differences and gravity effect. The flowing medium has a speed distribution that is characterized by the flow field. A flow field is characterized by the fact that the speed of the medium (gas or fluid particles) flows there is assigned at any time. Mass flows are observed in flow mechanics.  In the wind tunnel on a model of the slear car, string lines visibly made visible A mechanical flow field can be visualized with the following field lines: Strom lines affect the speed vectors in the flow field, which is “frozen” at a time. Strom lines are the integral curves of the flow field at a time. The mass current is the same everywhere between two streamlines, see electricity function: [2] Strom liner compression (narrowing) means acceleration of the current. Strom liner dilution (settlement) means delay in the current. Strom lines cannot be kinked and do not cut themselves, since two different fluid speeds are not possible at one point. Coat lines trace the path of several particles that are released one after the other at the same position of a flow field, see picture. Train lines or rail curves trace the path of a single particle in a flow field. In an inpatient flow of flow as in the picture, electricity, string and rail lines match.  Flow field (red, background) around a cylinder (turquoise) [3] Other graphic presentation options are: ISOTACHEN: Lines of the same speed. Hodographer: The amount of endpoints of the speed vectors observed in an initial current in a fixed point. The topology offers an additional description option, which is marked by staunch points in the flow point (saddle points, S in the image with the cylinder flow) and on the field edge (half -saddle point H) and vertebrae (Foki f). [4] : 49 Global map the wind currents \u2191  Flow . In: Lexicon of physics . Spectrum Akademischer Verlag, Heidelberg ( Spektrum.de ).   \u2191 a b c d  H. Sigloch: Technical fluid mechanics . Springer Vieweg, Berlin, Heidelberg 2014, ISBN 978-3-642-54291-6, S.  53\u201355 , doi: 10,1007\/978-3-642-54292-3 ( limited preview in the Google book search [accessed on March 10, 2022]).   \u2191  Video: Development of vertebrae in water currents – 1. Development of vertebrae and artificial influence of vertebral formation . Institute for Scientific Film (IMF) 1936, provided by the Technical Information Library (TIB), DOI: 10.3203\/IWF\/C-1 .  \u2191  H. Oertel (Hrsg.): Prandtl leader through the flow theory . Basics and phenomena. 13th edition. Springer Vieweg, 2012, ISBN 978-3-8348-1918-5.    "},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/all2en\/wiki1\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/all2en\/wiki1\/flow-field-wikipedia\/#breadcrumbitem","name":"Flow field – Wikipedia"}}]}]