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Garfield Thomas Water Tunnel
The Garfield Thomas Water Tunnel is one of the U.S. Navy's principal experimental hydrodynamic research facilities and is operated by the Penn State Applied Research Laboratory. The facility was completed and entered operation in 1949. The facility is named after Lieutenant W. Garfield Thomas Jr., a Penn State journalism graduate who was killed in World War II. For a long time, the Garfield Thomas Water Tunnel was the largest circulating water tunnel in the world. It has been declared a historic mechanical engineering landmark by the American Society of Mechanical Engineers. Today, in addition to many of its Navy projects, the facility tunnel-based research has expanded into pumps for the Space Shuttle, advanced propulsors for ships, heating and cooling systems, artificial heart valves, vacuum cleaner fans, and other pump and propulsor related products. History After the end of WW II, the US military started investing heavily in higher education nationwide. At the same time, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Education
Education is a purposeful activity directed at achieving certain aims, such as transmitting knowledge or fostering skills and character traits. These aims may include the development of understanding, rationality, kindness, and honesty. Various researchers emphasize the role of critical thinking in order to distinguish education from indoctrination. Some theorists require that education results in an improvement of the student while others prefer a value-neutral definition of the term. In a slightly different sense, education may also refer, not to the process, but to the product of this process: the mental states and dispositions possessed by educated people. Education originated as the transmission of cultural heritage from one generation to the next. Today, educational goals increasingly encompass new ideas such as the liberation of learners, skills needed for modern society, empathy, and complex vocational skills. Types of education are commonly divided into formal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher learning in the United States and one of the most prestigious and highly ranked universities in the world. The university is composed of ten academic faculties plus Harvard Radcliffe Institute. The Faculty of Arts and Sciences offers study in a wide range of undergraduate and graduate academic disciplines, and other faculties offer only graduate degrees, including professional degrees. Harvard has three main campuses: the Cambridge campus centered on Harvard Yard; an adjoining campus immediately across Charles River in the Allston neighborhood of Boston; and the medical campus in Boston's Longwood Medical Area. Harvard's endowment is valued at $50.9 billion, making it the wealthiest academic institution in the world. Endowment inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horsepower
Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are the mechanical horsepower (or imperial horsepower), which is about 745.7 watts, and the metric horsepower, which is approximately 735.5 watts. The term was adopted in the late 18th century by Scottish engineer James Watt to compare the output of steam engines with the power of draft horses. It was later expanded to include the output power of other types of piston engines, as well as turbines, electric motors and other machinery. The definition of the unit varied among geographical regions. Most countries now use the SI unit watt for measurement of power. With the implementation of the EU Directive 80/181/EEC on 1 January 2010, the use of horsepower in the EU is permitted only as a supplementary unit. History The development of the stea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Towed Array Sonar
A towed array sonar is a system of hydrophones towed behind a submarine or a surface ship on a cable. Trailing the hydrophones behind the vessel, on a cable that can be kilometers long, keeps the array's sensors away from the ship's own noise sources, greatly improving its signal-to-noise ratio, and hence the effectiveness of detecting and tracking faint contacts, such as quiet, low noise-emitting submarine threats, or seismic signals. A towed array offers superior resolution and range compared with hull mounted sonar. It also covers the baffles, the blind spot of hull mounted sonar. However, effective use of the system limits a vessel's speed and care must be taken to protect the cable from damage. History During World War I, a towed sonar array known as the "Electric Eel" was developed by Harvey Hayes, a U.S. Navy physicist. This system is believed to be the first towed sonar array design. It employed two cables, each with a dozen hydrophones attached. The project was discontin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerometer
An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is acceleration in a fixed coordinate system. For example, an accelerometer at rest on the surface of the Earth will measure an acceleration due to Earth's gravity, straight upwards (by definition) of g ≈ 9.81 m/s2. By contrast, accelerometers in free fall (falling toward the center of the Earth at a rate of about 9.81 m/s2) will measure zero. Accelerometers have many uses in industry and science. Highly sensitive accelerometers are used in inertial navigation systems for aircraft and missiles. Vibration in rotating machines is monitored by accelerometers. They are used in tablet computers and digital cameras so that images on screens are always displayed upright. In unmanned aerial vehicles, accelerometers help to stabilise flight. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Motion Test
In marine engineering, a ship motion test is hydrodynamic test performed with ship models for the purpose of designing a new (full sized) ship, or refining the design of a ship to improve its performance at sea. Tests are carried out in a ship model basin or "towing tank". There are various types of test: the model may be towed along a straight line or circular path, and may be subjected to oscillations. Forces acting on the vessel are measured using a dynamometer. The tests may be evaluating the overall design, or focusing on the characteristics of a propeller. Straight line test The velocity-dependent derivatives Yv and Nv of the ship at any draft and trim can be determined from the model test carried in the towing tank. The model is towed with a constant velocity corresponding to a given ship Froude number at various angles of attack, β. A dynamometer at the origin O, measures the force Y and the moment N experienced by the model at each value of β. The dimensional ship value ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrophone
A hydrophone ( grc, ὕδωρ + φωνή, , water + sound) is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a sound wave. Some piezoelectric transducers can also serve as a sound projector, but not all have this capability, and some may be destroyed if used in such a manner. A hydrophone can detect airborne sounds, but will be insensitive because it is designed to match the acoustic impedance of water, a denser fluid than air. Sound travels 4.3 times faster in water than in air, and a sound wave in water exerts a pressure 60 times that exerted by a wave of the same amplitude in air. Similarly, a standard microphone can be buried in the ground, or immersed in water if it is put in a waterproof container, but will give poor performance due to the similarly bad acoustic impedance match. History The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitot Tube
A pitot ( ) tube (pitot probe) measures fluid flow velocity. It was invented by a French engineer, Henri Pitot, in the early 18th century, and was modified to its modern form in the mid-19th century by a French scientist, Henry Darcy. It is widely used to determine the airspeed of aircraft; the water speed of boats; and the flow velocity of liquids, air, and gases in industry. Theory of operation The basic pitot tube consists of a tube pointing directly into the fluid flow. As this tube contains fluid, a pressure can be measured; the moving fluid is brought to rest (stagnates) as there is no outlet to allow flow to continue. This pressure is the stagnation pressure of the fluid, also known as the total pressure or (particularly in aviation) the pitot pressure. The measured stagnation pressure cannot itself be used to determine the fluid flow velocity (airspeed in aviation). However, Bernoulli's equation states: :Stagnation pressure = static pressure + dynamic pressure Whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impeller
An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. In pumps An impeller is a rotating component of a centrifugal pump that accelerates fluid outward from the center of rotation, thus transferring energy from the motor that drives the pump to the fluid being pumped. The velocity achieved by the impeller transfers into pressure when the outward movement of the fluid is confined by the pump casing. An impeller is usually a short cylinder with an open inlet (called an eye) to accept incoming fluid, vanes to push the fluid radially, and a splined, keyed, or threaded bore to accept a drive shaft. It can be cheaper to cast an impeller and its spindle as one piece, rather than separately. This combination is sometimes referred to simply as the "rotor." Types Open impellers An open impeller has a hub with attached vanes and is mounted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garfield Thomas Water Tunnel
The Garfield Thomas Water Tunnel is one of the U.S. Navy's principal experimental hydrodynamic research facilities and is operated by the Penn State Applied Research Laboratory. The facility was completed and entered operation in 1949. The facility is named after Lieutenant W. Garfield Thomas Jr., a Penn State journalism graduate who was killed in World War II. For a long time, the Garfield Thomas Water Tunnel was the largest circulating water tunnel in the world. It has been declared a historic mechanical engineering landmark by the American Society of Mechanical Engineers. Today, in addition to many of its Navy projects, the facility tunnel-based research has expanded into pumps for the Space Shuttle, advanced propulsors for ships, heating and cooling systems, artificial heart valves, vacuum cleaner fans, and other pump and propulsor related products. History After the end of WW II, the US military started investing heavily in higher education nationwide. At the same time, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garfield Thomas Water Tunnel (1948)
The Garfield Thomas Water Tunnel is one of the U.S. Navy's principal experimental hydrodynamic research facilities and is operated by the Penn State Applied Research Laboratory. The facility was completed and entered operation in 1949. The facility is named after Lieutenant W. Garfield Thomas Jr., a Penn State journalism graduate who was killed in World War II. For a long time, the Garfield Thomas Water Tunnel was the largest circulating water tunnel in the world. It has been declared a historic mechanical engineering landmark by the American Society of Mechanical Engineers. Today, in addition to many of its Navy projects, the facility tunnel-based research has expanded into pumps for the Space Shuttle, advanced propulsors for ships, heating and cooling systems, artificial heart valves, vacuum cleaner fans, and other pump and propulsor related products. History After the end of WW II, the US military started investing heavily in higher education nationwide. At the same time, Har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eric A
The given name Eric, Erich, Erikk, Erik, Erick, or Eirik is derived from the Old Norse name ''Eiríkr'' (or ''Eríkr'' in Old East Norse due to monophthongization). The first element, ''ei-'' may be derived from the older Proto-Norse ''* aina(z)'', meaning "one, alone, unique", ''as in the form'' ''Æ∆inrikr'' explicitly, but it could also be from ''* aiwa(z)'' "everlasting, eternity", as in the Gothic form ''Euric''. The second element ''- ríkr'' stems either from Proto-Germanic ''* ríks'' "king, ruler" (cf. Gothic ''reiks'') or the therefrom derived ''* ríkijaz'' "kingly, powerful, rich, prince"; from the common Proto-Indo-European root * h₃rḗǵs. The name is thus usually taken to mean "sole ruler, autocrat" or "eternal ruler, ever powerful". ''Eric'' used in the sense of a proper noun meaning "one ruler" may be the origin of ''Eriksgata'', and if so it would have meant "one ruler's journey". The tour was the medieval Swedish king's journey, when newly elected, to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
