|
Electrohydrodynamics
Electrohydrodynamics (EHD), also known as electro-fluid-dynamics (EFD) or electrokinetics, is the study of the dynamics of electrically charged fluids. Electrohydrodynamics (EHD) is a joint domain of electrodynamics and fluid dynamics mainly focused on the fluid motion induced by electric fields. EHD, in its simplest form, involves the application of an electric field to a fluid medium, resulting in fluid flow, form, or properties manipulation. These mechanisms arise from the interaction between the electric fields and charged particles or polarization effects within the fluid. The generation and movement of charge carriers (ions) in a fluid subjected to an electric field are the underlying physics of all EHD-based technologies. The electric forces acting on particles consist of electrostatic (Coulomb) and electrophoresis force (first term in the following equation)., dielectrophoretic force (second term in the following equation), and electrostrictive force (third term in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrohydrodynamic Thruster
An ion-propelled aircraft or ionocraft is an aircraft that uses electrohydrodynamics (EHD) to provide lift (force), lift or thrust in the air without requiring combustion or moving parts. Current designs do not produce sufficient thrust for crewed flight or useful loads. History Origins The principle of ionic wind propulsion with corona discharge, corona-generated charged particles was discovered soon after the discovery of electricity with references dating to 1709 in a book titled ''Physico-Mechanical Experiments on Various Subjects'' by Francis Hauksbee. VTOL "lifter" experiments American experimenter Thomas Townsend Brown spent much of his life working on the principle, under the mistaken impression that it was an anti-gravity effect, which he named the Biefeld–Brown effect. Since his devices produced thrust in the direction of the field gradient, regardless of the direction of gravity, and did not work in a vacuum, other workers realized that the effect was due to E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biefeld–Brown Effect
The Biefeld–Brown effect is an electrical phenomenon, first noticed by inventor Thomas Townsend Brown in the 1920s, where high voltage applied to the electrodes of an asymmetric capacitor causes a net propulsive force toward the smaller electrode. Brown believed this effect was an anti-gravity force, and referred to as " electrogravitics" based on it being an electricity/gravity phenomenon. Later researchers suspect that the poor vacuum of Brown's apparatus created an ionic wind or ion drift that produced thrust by transferring its momentum to surrounding neutral particles. Overview It is generally assumed that the Biefeld–Brown effect produces an ionic wind that transfers its momentum to surrounding neutral particles. It describes a force observed on an asymmetric capacitor when high voltage is applied to the capacitor's electrodes. Once suitably charged up to high DC potentials, a thrust at the negative terminal, pushing it away from the positive terminal, is generated. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Townsend Brown
Thomas Townsend Brown (March 18, 1905 – October 27, 1985) was an American inventor whose research into odd electrical effects led him to believe he had discovered a type of anti-gravity caused by strong electric fields. Instead of being an anti-gravity force, what Brown observed has generally been attributed to electrohydrodynamics, the movement of charged particles that transfer their momentum to surrounding neutral particles in the air, also called "ionic drift" or " ionic wind". For most of Brown's life, he attempted to develop devices based on his ideas, trying to promote them for use by industry and the military. The phenomena came to be called the "Biefeld–Brown effect" and " electrogravitics". Brown's research influenced some amateur experimenters who build " ionic propulsion lifters" powered by high voltage. There are still claims that Brown discovered anti-gravity, an idea popular with the unidentified flying object (UFO) community and spawning many conspiracy theories ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamics (mechanics)
In physics, dynamics or classical dynamics is the study of forces and their effect on motion. It is a branch of classical mechanics, along with ''statics'' and ''kinematics''. The ''fundamental principle of dynamics'' is linked to Newton's second law. Subdivisions Rigid bodies Fluids Applications Classical dynamics finds many applications: * ''Aerodynamics'', the study of the motion of air * '' Brownian dynamics'', the occurrence of Langevin dynamics in the motion of particles in solution * '' File dynamics'', stochastic motion of particles in a channel * ''Flight dynamics'', the science of aircraft and spacecraft design * ''Molecular dynamics'', the study of motion on the molecular level * '' Langevin dynamics'', a mathematical model for stochastic dynamics * '' Orbital dynamics'', the study of the motion of rockets and spacecraft * '' Stellar dynamics'', a description of the collective motion of stars * '' Vehicle dynamics, the study of vehicles in motion Generalizations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfluidics
Microfluidics refers to a system that manipulates a small amount of fluids (10−9 to 10−18 liters) using small channels with sizes of ten to hundreds of micrometres. It is a multidisciplinary field that involves molecular analysis, molecular biology, and microelectronics. It has practical applications in the design of systems that process low volumes of fluids to achieve multiplexing, automation, and high-throughput screening. Microfluidics emerged in the beginning of the 1980s and is used in the development of inkjet printheads, DNA chips, lab-on-a-chip technology, micro-propulsion, and micro-thermal technologies. Typically, micro means one of the following features: * Small volumes (μL, nL, pL, fL) * Small size * Low energy consumption * Microdomain effects Typically microfluidic systems transport, mix, separate, or otherwise process fluids. Various applications rely on passive fluid control using capillary forces, in the form of capillary flow modifying elements, akin to f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Field
An electric field (sometimes called E-field) is a field (physics), physical field that surrounds electrically charged particles such as electrons. In classical electromagnetism, the electric field of a single charge (or group of charges) describes their capacity to exert attractive or repulsive forces on another charged object. Charged particles exert attractive forces on each other when the sign of their charges are opposite, one being positive while the other is negative, and repel each other when the signs of the charges are the same. Because these forces are exerted mutually, two charges must be present for the forces to take place. These forces are described by Coulomb's law, which says that the greater the magnitude of the charges, the greater the force, and the greater the distance between them, the weaker the force. Informally, the greater the charge of an object, the stronger its electric field. Similarly, an electric field is stronger nearer charged objects and weaker f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wired Magazine
''Wired'' is a bi-monthly American magazine that focuses on how emerging technologies affect culture, the economy, and politics. It is published in both print and Online magazine, online editions by Condé Nast. The magazine has been in publication since its launch in January 1993. Its editorial office is based in San Francisco, California, with its business headquarters located in New York City. ''Wired'' quickly became recognized as the voice of the emerging digital economy and culture and a pace setter in print design and web design. From 1998 until 2006, the magazine and its website, ''Wired.com'', experienced separate ownership before being fully consolidated under Condé Nast in 2006. It has won multiple National Magazine Awards and has been credited with shaping discourse around the digital revolution. The magazine also coined the term Crowdsourcing, ''crowdsourcing'', as well as its annual tradition of handing out Vaporware Awards. ''Wired'' has launched several in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Generator
In electricity generation, a generator, also called an ''electric generator'', ''electrical generator'', and ''electromagnetic generator'' is an electromechanical device that converts mechanical energy to electrical energy for use in an external circuit. In most generators which are rotating machines, a source of kinetic power rotates the generator's shaft, and the generator produces an electric current at its output terminals which flows through an external circuit, powering electrical loads. Sources of mechanical energy used to drive generators include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. Generators produce nearly all of the electric power for worldwide electric power grids. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potential Difference
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the ''volt'' (''V''). The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in a generator). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. Since it is the difference in electric potential, it is a physical scalar quantity. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Ioniser
An air ioniser (or negative ion generator or Chizhevsky's chandelier) is a device that uses high voltage to ionization, ionise (electrically charge) Atmosphere of Earth, air molecules. Negative ions, or anions, are particles with one or more extra electrons, conferring a net negative charge to the particle. Cations are positive ions missing one or more electrons, resulting in a net positive charge. Some commercial air purifiers are designed to generate negative ions. Another type of air ioniser is the electrostatic discharge (ESD) ioniser (balanced ion generator) used to neutralise static charge. History In 1918 Alexander Chizhevsky created the first air ioniser for ion therapy. It was originally used for animal health in agriculture. This discovery ignited Coppy Laws, Cecil Alfred "Coppy" Laws' interest in the phenomenon of air ionisation. Laws has been credited with being the inventor of the domestic air ioniser. Ionic air purifiers Air ionisers are used in air purifiers to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
