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IEPR
The engine pressure ratio (EPR) is the total pressure ratio across a jet engine, measured as the ratio of the total pressure at the exit of the propelling nozzle divided by the total pressure at the entry to the compressor. Jet engines use either EPR or compressor/fan RPM as an indicator of thrust. When EPR is used, the pressures are measured in front of the compressor and behind the turbine. Integrated engine pressure ratio The integrated engine pressure ratio (IEPR) is a ratio used on some turbofans to include fan discharge total pressure and compressor inlet total pressure. If compressor inlet pressure is P0 and fan discharge total pressure is P1, then the integrated engine pressure ratio will be P1 /P0. The IEPR is an engine indicator system unique to the Rolls-Royce RB211. See also *Jet engine performance *Turbofan References * The Boeing Company '' Engine thrust control system 'US Patent 4248042Includes Boeing The Boeing Company, or simply Boeing (), is an Ame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbofan
A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the additional fan stage. It consists of a gas turbine engine which achieves mechanical energy from combustion, and a ducted fan that uses the mechanical energy from the gas turbine to force air rearwards. Thus, whereas all the air taken in by a turbojet passes through the combustion chamber and turbines, in a turbofan some of that air bypasses these components. A turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of these contributing to the thrust. The ratio of the mass-flow of air bypassing the engine core to the mass-flow of air passing through the core is referred to as the bypass ratio. The engine produces thrust through a combination of these two portions working together. Engines that use more Propel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Engine Performance
A jet engine converts fuel into thrust. One key metric of performance is the thermal efficiency; how much of the chemical energy (fuel) is turned into useful work (thrust propelling the aircraft at high speeds). Like a lot of heat engines, jet engines tend to not be particularly efficient (<50%); a lot of the fuel is "wasted". In the 1970s, economic pressure due to the rising cost of fuel resulted in increased emphasis on efficiency improvements for commercial airliners. Jet engine performance has been phrased as 'the end product that a jet engine company sells' and, as such, criteria include thrust, (specific) fuel consumption, time between overhauls, power-to-weight ratio. Some major factors affecting efficiency include the engine's overall pressure ratio, its bypass ratio and the turbine inlet temperature. Performance criteria reflect the level of technology used in the design of an engine, and the technology has been advancing continuously since the jet engine entered service i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbofan
A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the additional fan stage. It consists of a gas turbine engine which achieves mechanical energy from combustion, and a ducted fan that uses the mechanical energy from the gas turbine to force air rearwards. Thus, whereas all the air taken in by a turbojet passes through the combustion chamber and turbines, in a turbofan some of that air bypasses these components. A turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of these contributing to the thrust. The ratio of the mass-flow of air bypassing the engine core to the mass-flow of air passing through the core is referred to as the bypass ratio. The engine produces thrust through a combination of these two portions working together. Engines that use more Propel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Engine
A jet engine is a type of reaction engine, discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition may include Rocket engine, rocket, Pump-jet, water jet, and hybrid propulsion, the term typically refers to an internal combustion airbreathing jet engine, air-breathing jet engine such as a turbojet, turbofan, ramjet, pulse jet engine, pulse jet, or scramjet. In general, jet engines are internal combustion engines. Air-breathing jet engines typically feature a Axial compressor, rotating air compressor powered by a turbine, with the leftover power providing thrust through the propelling nozzle—this process is known as the Brayton cycle, Brayton thermodynamic cycle. Jet aircraft use such engines for long-distance travel. Early jet aircraft used turbojet engines that were relatively inefficient for subsonic flight. Most modern subsonic jet aircraft use more complex High-bypass turbofan, high-bypas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolls-Royce RB211
The Rolls-Royce RB211 is a British family of high-bypass turbofan engines made by Rolls-Royce Holdings, Rolls-Royce. The engines are capable of generating of thrust. The RB211 engine was the first production turbofan#Three-spool, three-spool engine and turned Rolls-Royce from a significant player in the aero-engine industry into a global leader. Originally developed for the Lockheed L-1011 TriStar, it entered service in 1972 and was the exclusive engine to power the L-1011. Mismanagement of the initial development and consequent cost issues led to the effective nationalisation of Rolls-Royce Limited, to save the workforce and the engine businesses important to the UK and many other aerospace and aircraft operating companies. In the early 1970s, the engine was reckoned by the company to be capable of at least 50 years of continuous development. The RB.211 was renamed, in 1989, to become the basis of the Rolls-Royce Trent family of engines when the RB211-524L was renamed to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing
The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support services. Boeing is among the largest global aerospace manufacturers; it is the fourth-largest defense contractor in the world based on 2022 revenue and is the largest exporter in the United States by dollar value. Boeing was founded by William E. Boeing in Seattle, Washington, on July 15, 1916. The present corporation is the result of the merger of Boeing with McDonnell Douglas on August 1, 1997. As of 2023, the Boeing Company's corporate headquarters is located in the Crystal City neighborhood of Arlington County, Virginia. The company is organized into three primary divisions: Boeing Commercial Airplanes (BCA), Boeing Defense, Space & Security (BDS), and Boeing Global Services (BGS). In 2021, Boeing recorded $62.3billion in sales. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering Ratios
Engineering is the practice of using natural science, mathematics, and the engineering design process to solve problems within technology, increase efficiency and productivity, and improve systems. Modern engineering comprises many subfields which include designing and improving infrastructure, machinery, vehicles, electronics, materials, and energy systems. The discipline of engineering encompasses a broad range of more specialized fields of engineering, each with a more specific emphasis for applications of mathematics and science. See glossary of engineering. The word ''engineering'' is derived from the Latin . Definition The American Engineers' Council for Professional Development (the predecessor of the Accreditation Board for Engineering and Technology aka ABET) has defined "engineering" as: History Engineering has existed since ancient times, when humans devised inventions such as the wedge, lever, wheel and pulley, etc. The term ''engineering'' is derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
