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FENE-P
{{inline, date=June 2017 FENE-P is a continuous model of polymer. The name FENE stands for finitely extensible nonlinear elastic while P stands for the closure proposed by Peterlin. It takes the dumbbell version of the FENE model and assumed the Peterline statistical closure for the restoring force. Advantages FENE-P is one of few polymer models that can be used in fluid dynamics simulations ( CFD) since it removes the need of statistical averaging at each grid point at any instant in time. It is demonstrated to be able to capture some of the most important polymeric flow behaviors such as polymer turbulence drag reduction and shear thinning. It is the most commonly used polymer model that can be used in a turbulence simulation since turbulence DNS is already extremely expensive. Disadvantages Due to its simplifications FENE-P is not able to show the hysteresis Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anton Peterlin (physicist)
Anton Peterlin () (25 September 1908 – 24 March 1993) was a Slovenian physicist. Life and career Peterlin was born in Ljubljana, Slovenia. After receiving his D. Sc. in physics from Humboldt University of Berlin in Berlin, Germany in 1938, Peterlin accepted in 1939 the chair as a professor of physics at the University of Ljubljana, where he remained for 22 years. Besides his pedagogical duties, he accepted in 1947 the position of the founding director of the Jožef Stefan Institute in Ljubljana. In 1960, Peterlin left his home country. In order to be able to continue his theoretical research on macromolecules he accepted the position of a full professor and head of the Institute of Physics at the Technical University of Munich, Germany. Only a year later he relocated to North Carolina where he was entrusted with the directorship of the newly founded Camille Dreyfus Laboratory at the Research Triangle Institute, which was almost entirely devoted to basic research on polymers. He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer Turbulence Drag Reduction
In 1948 Toms discovered by experiments that the addition of a small amount of polymer into a turbulent Newtonian solvent (parts per million by weight), which results in a Non-Newtonian fluid solution, can reduce the skin frictional drag on a stationary surface by up to 80% . This technology has been successfully implemented to reduce pumping cost for oil pipelines, to increase the flow rate in fire fighting equipment and to help irrigation and drainage (Sellin & Ollis, 1980; Khalil et al., 2002). It also has potential applications in the design of ship and submarine hulls to achieve an increased speed and reduced energy cost. See also * Drag reducing agent * FENE-P * Non-Newtonian fluid * Direct numerical simulation A direct numerical simulation (DNS)Here the origin of the term ''direct numerical simulation'' (see e.g. p. 385 in ) owes to the fact that, at that time, there were considered to be just two principal ways of getting ''theoretical'' results r ... External link ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek ''poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'', mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FENE
Fene is a municipality in the province of A Coruña in the autonomous community of Galicia in northwestern Spain. It is located to the northeast of Galicia on the Ria of Ferrol. Economy The Navantia Shipyards and services in the parts which are nearer Ferrol, the rest of the borough devotes itself to farming, agriculture and fishing. In the late 1960s the gantry crane of the shipyards of Astilleros y Talleres del Noroeste (ASTANO) in Ferrolterra was the largest in Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti .... References Municipalities in the Province of A Coruña {{galicia-geo-stub ... [...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 appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Thinning
In rheology, shear thinning is the non-Newtonian behavior of fluids whose viscosity decreases under shear strain. It is sometimes considered synonymous for pseudo-plastic behaviour, and is usually defined as excluding time-dependent effects, such as thixotropy. Shear thinning is the most common type of non-Newtonian behavior of fluids and is seen in many industrial and everyday applications. Although shear thinning is generally not observed in pure liquids with low molecular mass or ideal solutions of small molecules like sucrose or sodium chloride, it is often observed in polymer solutions and molten polymers, as well as complex fluids and suspensions like ketchup, whipped cream, blood, paint, and nail polish. Theories behind shear thinning behaviour Though the exact cause of shear thinning is not fully understood, it is widely regarded to be the effect of small structural changes within the fluid, such that microscale geometries within the fluid rearrange to facilitate s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe. The onset of turbulence can be predicted by the dimensionless Rey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Numerical Simulation
A direct numerical simulation (DNS)Here the origin of the term ''direct numerical simulation'' (see e.g. p. 385 in ) owes to the fact that, at that time, there were considered to be just two principal ways of getting ''theoretical'' results regarding turbulence, namely via turbulence theories (like the direct interaction approximation) and ''directly'' from solution of the Navier–Stokes equations. is a simulation in computational fluid dynamics (CFD) in which the Navier–Stokes equations are numerically solved without any turbulence model. This means that the whole range of spatial and temporal scales of the turbulence must be resolved. All the spatial scales of the turbulence must be resolved in the computational mesh, from the smallest dissipative scales ( Kolmogorov microscales), up to the integral scale L, associated with the motions containing most of the kinetic energy. The Kolmogorov scale, \eta, is given by :\eta=(\nu^/\varepsilon)^ where \nu is the kinematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hysteresis
Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of the moment often form a loop or hysteresis curve, where there are different values of one variable depending on the direction of change of another variable. This history dependence is the basis of memory in a hard disk drive and the remanence that retains a record of the Earth's magnetic field magnitude in the past. Hysteresis occurs in ferromagnetic and ferroelectric materials, as well as in the deformation of rubber bands and shape-memory alloys and many other natural phenomena. In natural systems it is often associated with irreversible thermodynamic change such as phase transitions and with internal friction; and dissipation is a common side effect. Hysteresis can be found in physics, chemistry, engineering, biology, and ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
