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Flow Visualization
Flow visualization or flow visualisation in fluid dynamics is used to make the flow patterns visible, in order to get qualitative or quantitative information on them. Overview Flow visualization is the art of making flow patterns visible. Most fluids (air, water, etc.) are transparent, thus their flow patterns are invisible to the naked eye without methods to make them this visible. Historically, such methods included experimental methods. With the development of computer models and CFD simulating flow processes (e.g. the distribution of air-conditioned air in a new car), purely computational methods have been developed. Methods of visualization In experimental fluid dynamics, flows are visualized by three methods: * Surface flow visualization: This reveals the flow streamlines in the limit as a solid surface is approached. Colored oil applied to the surface of a wind tunnel model provides one example (the oil responds to the surface shear stress and forms a patter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cessna 182 Model-wingtip-vortex
Cessna () is an American brand of general aviation aircraft owned by Textron Aviation since 2014, headquartered in Wichita, Kansas. Originally, it was a brand of the Cessna Aircraft Company, an American general aviation aircraft manufacturing corporation also headquartered in Wichita. The company produced small, piston-powered aircraft, as well as business jets. For much of the mid-to-late 20th century, Cessna was one of the highest-volume and most diverse producers of general aviation aircraft in the world. It was founded in 1927 by Clyde Cessna and Victor Roos and was purchased by General Dynamics in 1985, then by Textron, Inc. in 1992. In March 2014, when Textron purchased the Beechcraft and Hawker Aircraft corporations, Cessna ceased operations as a subsidiary company and joined the others as one of the three distinct brands produced by Textron Aviation. Throughout its history, and especially in the years following World War II, Cessna became best-known for producing high- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometry
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, remote sensing, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce interfer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streamlet (scientific Visualization)
A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams are usually called rivers, while smaller, less voluminous and more intermittent streams are known as streamlets, brooks or creeks. The flow of a stream is controlled by three inputs – surface runoff (from precipitation or meltwater), daylighted subterranean water, and surfaced groundwater (spring water). The surface and subterranean water are highly variable between periods of rainfall. Groundwater, on the other hand, has a relatively constant input and is controlled more by long-term patterns of precipitation. The stream encompasses surface, subsurface and groundwater fluxes that respond to geological, geomorphological, hydrological and biotic controls. Streams are important as conduits in the water cycle, instruments in groundwater r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skin Friction Lines
In scientific visualization skin friction lines are used to visualize flows on 3D-surfaces. They are obtained by calculating the streamlines of a derived vector field on the surface, the wall shear stress. Skin friction Skin friction drag is a type of aerodynamic or hydrodynamic drag, which is resistant force exerted on an object moving in a fluid. Skin friction drag is caused by the viscosity of fluids and is developed from laminar drag to turbulent drag as a f ... arises from the friction of the fluid against the "skin" of the object that is moving through it and forms a vector at each point on the surface. A skin friction line is a curve on the surface tangent to skin friction vectors. A limit streamline is a streamline where the distance normal to the surface tends to zero. Limit streamlines and skin friction lines coincide. The lines can be visualized by placing a viscous film on the surface. The skin friction lines may exhibit a number of different types of singularities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheoscopic Fluid
Rheoscopic fluid means "current showing" fluid. Such liquids are effective in visualizing dynamic currents in fluids, such as convection and laminar flow. They are microscopic crystalline platelets such as mica, metallic flakes, or fish scales in suspension in a fluid such as water or glycol stearate. When the fluid is put in motion, the suspended particles orient themselves in localized, preferential alignment, larger parts of the fluid moving sheer parallel to other parts of the fluid. With appropriate illumination, the particle-filled fluid will reflect differing intensities of light. * Kalliroscope *Reynolds number In fluid mechanics, the Reynolds number () is a dimensionless quantity that helps predict fluid flow patterns in different situations by measuring the ratio between inertial and viscous forces. At low Reynolds numbers, flows tend to be domi ... External linksUniversity of Chicago Materials Research Centre Demonstration [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image-based Flow Visualization
In scientific visualization, image-based flow visualization (or visualisation) is a computer modelling technique developed by Jarke van Wijk to visualize two dimensional flows of liquids such as water and air, like the wind movement of a tornado. Compared with integration techniques it has the advantage of producing a whole image at every step, as the technique relies upon graphical computing methods for frame-by-frame capture of the model of advective transport of a decaying dye. It is a method from the texture advection family. Principle The core idea is to create a noise texture on a regular grid and then bend this grid according to the flow (the vector field). The bent grid is then sampled at the original grid locations. Thus, the output is a version of the noise, that is displaced according to the flow. The advantage of this approach is that it can be accelerated on modern graphics hardware, thus allowing for real-time Real-time or real time describes various operations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Visualization
Scientific visualization ( also spelled scientific visualisation) is an interdisciplinary branch of science concerned with the visualization of scientific phenomena.Michael Friendly (2008)"Milestones in the history of thematic cartography, statistical graphics, and data visualization" It is also considered a subset of computer graphics, a branch of computer science. The purpose of scientific visualization is to graphically illustrate scientific data to enable scientists to understand, illustrate, and glean insight from their data. Research into how people read and misread various types of visualizations is helping to determine what types and features of visualizations are most understandable and effective in conveying information. History One of the earliest examples of three-dimensional scientific visualisation was Maxwell's thermodynamic surface, sculpted in clay in 1874 by James Clerk Maxwell. This prefigured modern scientific visualization techniques that use computer graph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Flow
Elementary flow is a collection of basic flows from which it is possible to construct more complex flows by superposition. Some of the flows reflect specific cases and constraints such as incompressible or irrotational flows, or both, as in the case of potential flow. Two-dimensional uniform flow Given a uniform velocity of a fluid at any position in space: :\mathbf = v_0 \cos(\theta_0) \mathbf_x +v_0 \sin(\theta_0) \mathbf_y This flow is incompressible because the velocity is constant, the first derivatives of the velocity components are zero, and the total divergence is zero: \nabla \cdot \mathbf = 0 Given the circulation is always zero the flow is also irrotational, we can derive this from the Kelvin's circulation theorem and from the explicit computation of the vorticity: :\omega_z = \frac - \frac = 0 Being incompressible and two-dimensional, this flow is constructed from a stream function: :v_x = \frac :v_y = - \frac from which :\psi = - v_0 \sin (\theta_0) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computational Fluid Dynamics
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid ( liquids and gases) with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved, and are often required to solve the largest and most complex problems. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulent flows. Initial validation of such software is typically performed using experimental apparatus such as wind tunnels. In addition, previously performed analytical or empirical analysis of a particular problem can be used for comparison. A final validation is often performed using full-scale testing, such as flight tests. CFD is applied to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texture Advection
Texture may refer to: Science and technology * Surface texture, the texture means smoothness, roughness, or bumpiness of the surface of an object * Texture (roads), road surface characteristics with waves shorter than road roughness * Texture (cosmology), a theoretical topological defect in the structure of spacetime * Texture (crystalline), material's individual crystallites sharing some degree of orientation * Texture (geology), a physical appearance or character of a rock * Texture mapping, a bitmap image applied to a surface in computer graphics * Soil texture, a relative proportion of grain sizes of a soil * Scalar field Arts * Texture (visual arts), an element of design and its application in art Music * Texture (music), an overall sound created by the interaction of aspects of a piece of music * ''Textures'' (album), a 1989 album by Brian Eno * Textures (band), a metal band from the Netherlands, who formed in 2001 in Tilburg Other uses * Texture (app), a digital app giv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streamlines, Streaklines, And Pathlines
Streamlines, streaklines and pathlines are field lines in a fluid flow. They differ only when the flow changes with time, that is, when the flow is not steady. Considering a velocity vector field in three-dimensional space in the framework of continuum mechanics, we have that: * Streamlines are a family of curves whose tangent vectors constitute the velocity vector field of the flow. These show the direction in which a massless fluid element will travel at any point in time. * Streaklines are the loci of points of all the fluid particles that have passed continuously through a particular spatial point in the past. Dye steadily injected into the fluid at a fixed point extends along a streakline. * Pathlines are the trajectories that individual fluid particles follow. These can be thought of as "recording" the path of a fluid element in the flow over a certain period. The direction the path takes will be determined by the streamlines of the fluid at each moment in time. * T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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