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LAPCAT
LAPCAT (Long-Term Advanced Propulsion Concepts and Technologies) was a 36-month European FP6 study to examine ways to produce engines for a Mach number 4-8 hypersonic flight aircraft. The project ended in April 2008. It was funded by the European Commission research and development fund (rather than ESA), and cost 7 million euros. LAPCAT II, a 10 million euro, four-year, follow on project, started in October 2008. The study aims to refine some of the results of the first study "allowing the definition of a detailed development roadmap" of a Mach five vehicle. Objectives Two major technologies were to be considered: * ram-compression, which needs an additional propulsion system to achieve its minimum working speed. * active compression, which has an upper Mach number limitation but can accelerate a vehicle up to its cruise speed. Key objectives were the definition and evaluation of: * different propulsion cycles and concepts for high-speed flight at Mach 4 to 8 such as turbine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LAPCAT And LAPCAT II Logos
LAPCAT (Long-Term Advanced Propulsion Concepts and Technologies) was a 36-month European FP6 study to examine ways to produce engines for a Mach number 4-8 hypersonic flight aircraft. The project ended in April 2008. It was funded by the European Commission research and development fund (rather than ESA), and cost 7 million euros. LAPCAT II, a 10 million euro, four-year, follow on project, started in October 2008. The study aims to refine some of the results of the first study "allowing the definition of a detailed development roadmap" of a Mach five vehicle. Objectives Two major technologies were to be considered: * ram-compression, which needs an additional propulsion system to achieve its minimum working speed. * active compression, which has an upper Mach number limitation but can accelerate a vehicle up to its cruise speed. Key objectives were the definition and evaluation of: * different propulsion cycles and concepts for high-speed flight at Mach 4 to 8 such as turbine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Engines A2
The Reaction Engines Limited LAPCAT Configuration A2 (called the LAPCAT A2) is a design study for a hypersonic speed jet airliner intended to provide, long range, high capacity commercial transportation. The aircraft was designed, as part of the European Union-funded Long-Term Advanced Propulsion Concepts and Technologies (LAPCAT) programme, by the British aerospace engineering firm Reaction Engines Limited, who said it could be developed into a working aircraft within 25 years once there is market demand for it. Development The vehicle is intended to have about range and good subsonic and supersonic speed fuel efficiency, thus avoiding the problems inherent in earlier supersonic aircraft. The top speed is projected to be Mach 5+. It calls for the use of liquid hydrogen as a fuel, which has twice the specific impulse of kerosene, and can be used to cool the vehicle and the air entering the engines via a precooler. Alan Bond, managing director of Reaction Engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersonic Transport
A supersonic transport (SST) or a supersonic airliner is a civilian supersonic aircraft designed to transport passengers at speeds greater than the speed of sound. To date, the only SSTs to see regular service have been Concorde and the Tupolev Tu-144. The last passenger flight of the Tu-144 was in June 1978 and it was last flown in 1999 by NASA. Concorde's last commercial flight was in October 2003, with a November 26, 2003 ferry flight being its last airborne operation. Following the permanent cessation of flying by Concorde, there are no remaining SSTs in commercial service. Several companies have each proposed a supersonic business jet, which may bring supersonic transport back again. Supersonic airliners have been the objects of numerous recent and ongoing design studies. Drawbacks and design challenges are excessive noise generation (at takeoff and due to sonic booms during flight), high development costs, expensive construction materials, high fuel consumption, extrem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Engines Scimitar
The Reaction Engines Scimitar is a derivative of the SABRE engine technology, but intended for jet airliners (the Reaction Engines LAPCAT A2 concept), rather than space launch applications. Consequently, most of the Scimitar engine technology is similar to SABRE but designed for much longer life. Both engines are designed around existing ramjet technology, but the Scimitar engine lacks the rocket features and has high bypass features for greater efficiency. The engines burn liquid hydrogen as fuel. The incorporation of lightweight heat exchangers in the main thermodynamic cycles of these engines is a new feature to aerospace propulsion. Similar studies of intercooler An intercooler is a heat exchanger used to cool a gas after compression. Often found in turbocharged engines, intercoolers are also used in air compressors, air conditioners, refrigeration and gas turbines. Internal combustion engines ...s used on jet engines show significant improvement of efficiency. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Engines Limited
Reaction Engines Limited is a British aerospace manufacturer based in Oxfordshire, England. History and personnel In , Reaction Engines was founded by Alan Bond (lead engineer on the British Interplanetary Society's Project Daedalus) and Richard Varvill and John Scott-Scott (the two principal Rolls-Royce engineers from the RB545 engine project). The company conducts research into space propulsion systems, centred on the development of the Skylon re-usable SSTO spaceplane. The three founders had worked together on the HOTOL project, funding for which had been withdrawn the previous year, in 1988. In 2015, BAE Systems agreed to buy a 20% stake in the company for £20.6m as part of an agreement to help develop Reaction Engines' Synergetic Air-Breathing Rocket Engine (SABRE) hypersonic engine designed to propel the Skylon orbiter. In April 2018, Boeing announced its investment in Reaction Engines, through Boeing HorizonX Ventures with a $37.3 million Series B funding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Engines SABRE
SABRE (Synergetic Air Breathing Rocket Engine) is a concept under development by Reaction Engines Limited for a hypersonic precooled hybrid air-breathing rocket engine. The engine is being designed to achieve single-stage-to-orbit capability, propelling the proposed Skylon spaceplane to low Earth orbit. SABRE is an evolution of Alan Bond's series of LACE-like designs that started in the early/mid-1980s for the HOTOL project. The design comprises a single combined cycle rocket engine with two modes of operation. The air-breathing mode combines a turbo-compressor with a lightweight air precooler positioned just behind the inlet cone. At high speeds this precooler cools the hot, ram-compressed air, which would otherwise reach a temperature that the engine could not withstand, leading to a very high pressure ratio within the engine. The compressed air is subsequently fed into the rocket combustion chamber where it is ignited along with stored liquid hydrogen. The high pressure r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Document Format
Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems.Adobe Systems IncorporatedPDF Reference, Sixth edition, version 1.23 (53 MB) Nov 2006, p. 33. Archiv/ref> Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images and other information needed to display it. PDF has its roots in "The Camelot Project" initiated by Adobe co-founder John Warnock in 1991. PDF was standardized as ISO 32000 in 2008. The last edition as ISO 32000-2:2020 was published in December 2020. PDF files may contain a variety of content besides flat text and graphics including logical structuring elements, interactive elements such as annotations and form-fields, layers, rich media (including video ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermodynamics
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of thermodynamics which convey a quantitative description using measurable macroscopic physical quantities, but may be explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to a wide variety of topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering and mechanical engineering, but also in other complex fields such as meteorology. Historically, thermodynamics developed out of a desire to increase the efficiency of early steam engines, particularly through the work of French physicist Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win the Napoleonic Wars. Scots-Irish physicist Lord Kelvin was the first to formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precooled Jet Engine
The precooled jet engine is a concept that enables jet engines with turbomachinery, as opposed to ramjets, to be used at high speeds. Precooling restores some or all of the performance degradation of the engine compressor (by preventing rotating stall/choking/reduced flow), as well as that of the complete gas generator (by maintaining a significant combustor temperature rise within a fixed turbine temperature limit), which would otherwise prevent flight with high ram temperatures. For higher flight speeds precooling may feature a cryogenic fuel-cooled heat exchanger before the air enters the compressor. After gaining heat and vapourising in the heat exchanger, the fuel (e.g. H2) burns in the combustor. Precooling using a heat exchanger has not been used in flight, but is predicted to have significantly high thrust and efficiency at speeds up to Mach 5.5. Precooled jet engine cycles were analyzed by Robert P. Carmichael in 1955. Pre-cooled engines avoid the need for an air conden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world, and the most widely used digital image format, with several billion JPEG images produced every day as of 2015. The term "JPEG" is an acronym for the Joint Photographic Experts Group, which created the standard in 1992. JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet, and later social media. JPEG compression is used in a number of image file formats. JPEG/ Exif is the most common image format used by digital cameras and other photographic image capture devices; along with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scramjet
A scramjet (supersonic combustion ramjet) is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully before combustion (hence ''ram''jet), but whereas a ramjet decelerates the air to subsonic velocities before combustion using shock cones, a scramjet has no shock cone and slows the airflow using shockwaves produced by its ignition source in place of a shock cone. This allows the scramjet to operate efficiently at extremely high speeds. History Before 2000 The Bell X-1 attained supersonic flight in 1947 and, by the early 1960s, rapid progress toward faster aircraft suggested that operational aircraft would be flying at "hypersonic" speeds within a few years. Except for specialized rocket research vehicles like the North American X-15 and other rocket-powered spacecraft, aircraft top speeds have remained level, generally in the range of M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
