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Turboprop-powered
A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. Fuel is then added to the compressed air in the combustor, where the fuel-air mixture then combusts. The hot combustion gases expand through the turbine stages, generating power at the point of exhaust. Some of the power generated by the turbine is used to drive the compressor and electric generator. The gases are then exhausted from the turbine. In contrast to a turbojet or turbofan, the engine's exhaust gases do not provide enough energy to create significant thrust, since almost all of the engine's power is used to drive the propeller. Technological aspects Exhaust thrust in a turboprop is sacrificed in favor of shaft power, which is obtained by extracting additional power (beyond that necessary to drive the compressor) from turbine expa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turboprop Operation-en
A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. Fuel is then added to the compressed air in the combustor, where the fuel-air mixture then combusts. The hot combustion gases expand through the turbine stages, generating power at the point of exhaust. Some of the power generated by the turbine is used to drive the compressor and electric generator. The gases are then exhausted from the turbine. In contrast to a turbojet or turbofan, the engine's exhaust gases do not provide enough energy to create significant thrust, since almost all of the engine's power is used to drive the propeller. Technological aspects Exhaust thrust in a turboprop is sacrificed in favor of shaft power, which is obtained by extracting additional power (beyond that necessary to drive the compressor) from turbine exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propulsive Efficiency For Different Engine Types And Mach Numbers
A prokinetic agent (also gastroprokinetic agent, gastrokinetic agent or propulsive) is a type of drug which enhances gastrointestinal motility by increasing the frequency or strength of contractions, but without disrupting their rhythm. They are used to treat certain gastrointestinal symptoms, including abdominal discomfort, bloating, constipation, heart burn, nausea, and vomiting; and certain gastrointestinal disorders, including irritable bowel syndrome, gastritis, gastroparesis, and functional dyspepsia. Most prokinetic agents are grouped under the Anatomical Therapeutic Chemical Classification System (a World Health Organization drug classification system), as ATC code A03F. Pharmacodynamics Activation of a wide range of serotonin receptors by serotonin itself or by certain prokinetic drugs results in enhanced gastrointestinal motility. Other prokinetic drugs may increase acetylcholine concentrations by stimulating the M1 receptor which causes acetylcholine release, or by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disc Loading
In fluid dynamics, disk loading or disc loading is the average pressure change across an actuator disk, such as an airscrew. Airscrews with a relatively low disk loading are typically called rotors, including helicopter main rotors and tail rotors; propellers typically have a higher disk loading. The V-22 Osprey tiltrotor aircraft has a high disk loading relative to a helicopter in the hover mode, but a relatively low disk loading in fixed-wing mode compared to a turboprop aircraft. Rotors Disc loading of a hovering helicopter is the ratio of its weight to the total main rotor disc area. It is determined by dividing the total helicopter weight by the rotor disc area, which is the area swept by the blades of a rotor. Disc area can be found by using the span of one rotor blade as the radius of a circle and then determining the area the blades encompass during a complete rotation. When a helicopter is being maneuvered, its disc loading changes. The higher the loading, the more po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igor Bensen
Igor Vasilevich Bensen (russian: И́горь Васи́льевич Бенсен; April 1, 1917 – February 10, 2000) was a Russian-American engineer. He founded Bensen Aircraft, a US company which produced a successful line of gyrogliders (rotor kites) and autogyros. Early life and education He was born in Rostov-on-Don, Russia, and eventually reached the United States in 1937. He began studies at age 17 while in Belgium, won a scholarship to study in the US three years later. He received a Bachelor of Science degree in mechanical engineering from Stevens Institute of Technology in Hoboken, New Jersey in 1940, later becoming a Registered Professional Engineer. Career Bensen flew his first towed gyroglider in 1954. He founded the Popular Rotorcraft Association (PRA) in 1962, a non-profit interest group for owners and homebuilders of autogyros and helicopters, based in Mentone, Indiana. He was the group's president from 1962 to 1971. Honors and awards He received an hon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Bevilaqua
Paul Bevilaqua is an aeronautics engineer at Lockheed Martin in California. In 1990, he invented the lift fan for the Joint Strike Fighter F-35B along with fellow Skunk Works engineer Paul Shumpert. In 2005, Bevilaqua was elected as a member of the National Academy of Engineering for his theoretical contributions, practical innovations, and increased operational utility in vertical takeoff and landing aircraft. Life and career Paul Bevilaqua earned a Doctorate in Aeronautics and Astronautics (subject: Turbulent wakes) at Purdue University in 1973. He was also an Air Force Lieutenant at Wright-Patterson Air Force Base (WP-AFB), where he began professional work in 1971. He became Deputy Director of the Energy Conversion Lab at WP-AFB, managed by jet inventor Hans von Ohain. In 1975, Paul left the Air Force to be a Manager of Advanced Programs at Rockwell International's Navy Aircraft Plant. In 1985, he was appointed Chief Aeronautical Scientist at Lockheed, trying to come up w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reciprocating Engine
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.''Thermodynamics: An Engineering Approach'' by Yunus A. Cengal and Michael A. Boles Common features in all types There may be one or more pistons. Each piston is inside a cylinder, into which a gas is intr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant-speed Propeller
In aeronautics, a variable-pitch propeller is a type of propeller (airscrew) with blades that can be rotated around their long axis to change the blade pitch. A controllable-pitch propeller is one where the pitch is controlled manually by the pilot. Alternatively, a constant-speed propeller is one where the pilot sets the desired engine speed ( RPM), and the blade pitch is controlled automatically without the pilot's intervention so that the rotational speed remains constant. The device which controls the propeller pitch and thus speed is called a propeller governor or constant speed unit. Reversible propellers are those where the pitch can be set to negative values. This creates reverse thrust for braking or going backwards without the need to change the direction of shaft revolution. Some aircraft have ground-adjustable propellers, however these are not considered variable-pitch. These are typically found only on light aircraft and microlights. Purpose When an aircraft is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of the body. The concept originated with the studies by Archimedes of the usage of levers, which is reflected in his famous quote: "''Give me a lever and a place to stand and I will move the Earth''". Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object around a specific axis. Torque is defined as the product of the magnitude of the perpendicular component of the force and the distance of the line of action of a force from the point around which it is being determined. The law of conservation of energy can also be used to understand torque. The symbol for torque is typically \boldsymbol\tau, the lowercase Greek letter ''tau''. When being referred to as moment of force, it is commonly denoted by . In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionless unit equal to 1, which it refers to as a revolution, but does not define the revolution as a unit. It defines a unit of rotational frequency equal to s−1. The superseded standard ISO 80000-3:2006 did however state with reference to the unit name 'one', symbol '1', that "The special name revolution, symbol r, for this unit is widely used in specifications on rotating machines." The International System of Units (SI) does not recognize rpm as a unit, and defines the unit of frequency, Hz, as equal to s−1. :\begin 1~&\text &&=& 60~&\text \\ \frac~&\text &&=& 1~&\text \end A corresponding but distinct quantity for describing rotation is angular velocity, for which the SI unit is the ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reduction Gear
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage. Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission of rotation from one gear to the next. Features of gears and gear trains include: * The gear ratio of the pitch circles of mating gears defines the speed ratio and the mechanical advantage of the gear set. * A planetary gear train provides high gear reduction in a compact package. * It is possible to design gear teeth for gears that are non-circular, yet still transmit torque smoothly. * The speed ratios of chain and belt drives are computed in the same way as gear ratios. See bicycle gearing. The transmission of rotation between contacting toothed wheels can be traced back to the Antikythera mechanism of Greece and the south-pointing chariot of China. Illustrations by the Renaissance scientist Georgius Agricola show gear trains wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
School Of Engineering, Massachusetts Institute Of Technology
The MIT School of Engineering (SoE) is one of the five schools of the Massachusetts Institute of Technology, located in Cambridge, Massachusetts, United States. SoE has eight academic departments and two interdisciplinary institutes. The School grants SB, MEng, SM, engineer's degrees, and PhD or ScD degrees. , the Dean of Engineering is Professor Anantha Chandrakasan. The school is the largest at MIT as measured by undergraduate and graduate enrollments and faculty members. Departments and initiatives Departments: * Aeronautics and Astronautics (Course 16) * Biological Engineering (Course 20) * Chemical Engineering (Course 10) * Civil and Environmental Engineering (Course 1) * Electrical Engineering and Computer Science (Course 6, joint department with MIT Schwarzman College of Computing) * Materials Science and Engineering (Course 3) * Mechanical Engineering (Course 2) * Nuclear Science and Engineering (Course 22) Institutes: * Institute for Medical Engineering and Science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bypass Ratio
The bypass ratio (BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for every 1 kg of air passing through the core. Turbofan engines are usually described in terms of BPR, which together with engine pressure ratio, turbine inlet temperature and fan pressure ratio are important design parameters. In addition, BPR is quoted for turboprop and unducted fan installations because their high propulsive efficiency gives them the overall efficiency characteristics of very high bypass turbofans. This allows them to be shown together with turbofans on plots which show trends of reducing specific fuel consumption (SFC) with increasing BPR. BPR is also quoted for lift fan installations where the fan airflow is remote from the engine and doesn't physically touch the engine core. Bypass provides a lower fuel consumption ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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