Thermawing

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The ThermaWing ice protection system uses a flexible, electrically conductive, graphite foil attached to a wing's leading edge. Once activated the foil heats quickly, melting and then shedding any ice.

Ice protection systems are designed to keep atmospheric ice from accumulating on aircraft surfaces, such as wings, propellers, rotor blades, engine intakes, and environmental control intakes. If ice is allowed to build up to a significant thickness it can change the shape of airfoils and flight control surfaces, degrading the performance, control or handling characteristics of the aircraft. An ice protection system either prevents formation of ice, or enables the aircraft to shed the ice before it can grow to a dangerous thickness.

Leading edge

The leading edge is the part of the wing that first contacts the air; alternatively it is the foremost edge of an airfoil section. The first is an aerodynamic definition, the second a structural one. As an example of the distinction, during a tailslide, from an aerodynamic point of view, the trailing edge becomes the leading edge and vice versa but from a structural point of view the leading edge remains unchanged.

Contents

Background

In 1998 NASA Glenn initiated the research and development of the Thermawing system for general aviation. Supported by the NASA SBIR (Small Business Innovative Research) program Kelly Aerospace Thermal Systems put the system into production. The FAA has certified the heater element configuration. [1]

General aviation civil use of aircraft excluding commercial transportation

General aviation (GA) is all civil aviation operations other than scheduled air services and non-scheduled air transport operations for remuneration or hire. General aviation flights range from gliders and powered parachutes to rotorcraft and corporate business jets. The majority of the world's air traffic falls into this category, and most of the world's airports serve general aviation exclusively.

NASA space-related agency of the United States government

The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research.

The original launch of the system was on Columbia Aircraft Manufacturing (now Cessna) 350 and 400 airframes. ThermaWing (formerly EVADE) employs 6 heaters, 3 heater control modules, one main electronic controller and one 7500 watt alternator.

Cessna Aircraft manufacturing subsidiary of Textron

The Cessna Aircraft Company was an American general aviation aircraft manufacturing corporation headquartered in Wichita, Kansas. Best known for small, piston-powered aircraft, Cessna also produced business jets. For many years the company was one of the highest-volume producers of general aviation aircraft in the world. Founded in 1927, it was purchased by General Dynamics in 1985, then by Textron, Inc. in 1995. In March 2014, when Textron purchased the Beechcraft and Hawker Aircraft businesses, Cessna ceased operations as a subsidiary company and joined the others as one of the three distinct brands produced by Textron Aviation.

Operation

The outer layer of the laminate is made of heat-conducting polyvinyl chloride. It offers the durability of a fluoropolymer. A zoned heater system is controlled by a solid-state processor. The leading edge (the "impingement" area) is kept warm, continually melting ice as it begins to form. The area just aft, the shedding zone, is normally kept below freezing, causing the streaming water to freeze and collect as ice. During a de-ice cycle the voltage is increased, raising the temperature of this aft shedding zone, melting the ice bond and shedding the ice via aerodynamic force. Once power is removed from the heater, the shedding zone immediately refreezes and resumes collecting ice until the next de-ice cycle. This system takes as little as 1 second per surface and only 33 seconds to deice the entire aircraft using a 60-second cycle.

Polyvinyl chloride Polymer

Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tonnes are produced per year.

A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The most well known fluoropolymer is polytetrafluoroethylene (Teflon).

Once armed, the system is digitally controlled with automatic shedding cycles activating at 41 °F.

See also

Related Research Articles

Aeroelasticity is the branch of physics and engineering that studies the interactions between the inertial, elastic, and aerodynamic forces that occur when an elastic body is exposed to a fluid flow. Although historical studies have been focused on aeronautical applications, recent research has found applications in fields such as energy harvesting and understanding snoring. The study of aeroelasticity may be broadly classified into two fields: static aeroelasticity, which deals with the static or steady response of an elastic body to a fluid flow; and dynamic aeroelasticity, which deals with the body's dynamic response. Aeroelasticity draws on the study of fluid mechanics, solid mechanics, structural dynamics and dynamical systems. The synthesis of aeroelasticity with thermodynamics is known as aerothermoelasticity, and its synthesis with control theory is known as aeroservoelasticity.

Stall (fluid dynamics) abrupt reduction in lift due to flow separation

In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded. The critical angle of attack is typically about 15 degrees, but it may vary significantly depending on the fluid, foil, and Reynolds number.

Leading-edge extension

A leading-edge extension (LEX) is a small extension to an aircraft wing surface, forward of the leading edge. The primary reason for adding an extension is to improve the airflow at high angles of attack and low airspeeds, to improve handling and delay the stall. A dog tooth can also improve airflow and reduce drag at higher speeds.

Thermostat component which maintains a setpoint temperature

A thermostat is a component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint.

Airfoil

An airfoil or aerofoil is the cross-sectional shape of a wing, blade, or sail.

NASA X-43

The X-43 was an experimental unmanned hypersonic aircraft with multiple planned scale variations meant to test various aspects of hypersonic flight. It was part of the X-plane series and specifically of NASA's Hyper-X program. It set several airspeed records for jet aircraft. The X-43 is the fastest aircraft on record at approximately Mach 9.6.

Grumman X-29 NASA research aircraft

The Grumman X-29 was an American experimental aircraft that tested a forward-swept wing, canard control surfaces, and other novel aircraft technologies. The X-29 was developed by Grumman, and the two built were flown by NASA and the United States Air Force. The aerodynamic instability of the X-29's airframe required the use of computerized fly-by-wire control. Composite materials were used to control the aeroelastic divergent twisting experienced by forward-swept wings, and to reduce weight. The aircraft first flew in 1984, and two X-29s were flight tested through 1991.

Bleed air produced by gas turbine engines is compressed air that is taken from the compressor stage of those engines, which is upstream of the fuel-burning sections. In modern airliner engines, two regulator valves turn on and off automatically and are controlled by at least "...two air supply and cabin pressure controllers (ASCPCs) which open and close appropriate valves. Engine bleed air comes from the high stage or low stage engine compressor section. Low stage air is used during high power setting operation, and high stage air is used during descent and other low power setting operations." Bleed air from that system can be utilized for internal cooling of the engine, cross-starting another engine, engine and airframe anti-icing, cabin pressurization, pneumatic actuators, air-driven motors, pressurizing the hydraulic reservoir, and waste and water storage tanks. Some engine maintenance manuals refer to such systems as "customer bleed air". Bleed air is valuable in an aircraft for two properties: high temperature and high pressure.

Flap (aeronautics) aircraft wing device used to increase lift by extending the trailing edge of the wing

Flaps are a kind of high-lift device used to increase the lift of an aircraft wing at a given airspeed. Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. Flaps are used for extra lift on takeoff. Flaps also cause an increase in drag in mid-flight, so they are retracted when not needed.

Deicing process of removing snow, ice or frost from a surface

De-icing is the process of removing snow, ice or frost from a surface. Anti-icing is understood to be the application of chemicals that not only de-ice but also remain on a surface and continue to delay the reformation of ice for a certain period of time, or prevent adhesion of ice to make mechanical removal easier.

USAir Flight 405 aviation accident

USAir Flight 405 was a regularly scheduled domestic passenger flight between LaGuardia Airport in Queens, New York City, New York, and Cleveland, Ohio. On March 22, 1992, a USAir Fokker F28, registration N485US, flying the route, crashed in poor weather in a partially inverted position in Flushing Bay, shortly after liftoff from LaGuardia. The undercarriage lifted off from the runway; however, the airplane failed to gain lift, flying only several meters above the ground. The aircraft then veered off the runway and hit multiple obstructions before coming to rest in Flushing Bay, just beyond the end of the runway. Of the 51 people on board, 27 were killed, including the captain and a member of the cabin crew.

Supercritical airfoil

A supercritical airfoil is an airfoil designed primarily to delay the onset of wave drag in the transonic speed range. Supercritical airfoils are characterized by their flattened upper surface, highly cambered ("downward-curved") aft section, and larger leading-edge radius compared with NACA 6-series laminar airfoil shapes. Standard wing shapes are designed to create lower pressure over the top of the wing. The camber of the wing determines how much the air accelerates around the wing. As the speed of the aircraft approaches the speed of sound, the air accelerating around the wing reaches Mach 1 and shockwaves begin to form. The formation of these shockwaves causes wave drag. Supercritical airfoils are designed to minimize this effect by flattening the upper surface of the wing.

Space Shuttle thermal protection system

The Space Shuttle thermal protection system (TPS) is the barrier that protected the Space Shuttle Orbiter during the searing 1,650 °C (3,000 °F) heat of atmospheric reentry. A secondary goal was to protect from the heat and cold of space while in orbit.

This is an alphabetical list of articles pertaining specifically to aerospace engineering. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.

In aviation, icing conditions are those atmospheric conditions that can lead to the formation of water ice on the surfaces of an aircraft, or within the engine as carburetor icing. Inlet icing is another engine-related danger, often occurring in jet aircraft. These icing phenomena do not necessarily occur together. Many aircraft, especially general aviation aircraft, are not certified for flight into known icing—icing conditions certain or likely to exist, based on pilot reports, observations, and forecasts.

Deicing boot

A deicing boot is a type of ice protection system installed on aircraft surfaces to permit a mechanical deicing in flight. Such boots are generally installed on the leading edges of wings and control surfaces as these areas are most likely to accumulate ice and any contamination could severely affect the aircraft's performance.

Boeing X-53 Active Aeroelastic Wing research aircraft by McDonnell Douglas, later Boeing

The X-53 Active Aeroelastic Wing (AAW) development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory (AFRL), Boeing Phantom Works and NASA's Dryden Flight Research Center, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet. Active Aeroelastic Wing Technology is a technology that integrates wing aerodynamics, controls, and structure to harness and control wing aeroelastic twist at high speeds and dynamic pressures. By using multiple leading and trailing edge controls like "aerodynamic tabs", subtle amounts of aeroelastic twist can be controlled to provide large amounts of wing control power, while minimizing maneuver air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. The flight program which first proved the use of AAW technology in full scale was the X-53 Active Aeroelastic Wing program.

ATA 100 contains the reference to the ATA numbering system which is a common referencing standard for commercial aircraft documentation. This commonality permits greater ease of learning and understanding for pilots, aircraft maintenance technicians, and engineers alike. The standard numbering system was published by the Air Transport Association on June 1, 1956. While the ATA 100 numbering system has been superseded, it continued to be widely used until it went out of date back in 2015, especially in documentation for general aviation aircraft, on aircraft Fault Messages and the electronic and printed manuals.

Most of the terms listed in Wikipedia glossaries are already defined and explained within Wikipedia itself. However, glossaries like this one are useful for looking up, comparing and reviewing large numbers of terms together. You can help enhance this page by adding new terms or writing definitions for existing ones.

References

  1. NASA (2007). Spinoff. Washington, DC: U.S. Government Printing Office. ISBN   978-0-16-079740-8.