A tiltrotor is a plane that produces lift and propulsion by means of one or more powered rotor (sometimes called proprotors ) installed in rotating engine pods or nacelles usually at the wingtips fixed or engine mounted on the fuselage with a drive shaft that transfers power to the rotor assembly mounted on the wingtips. It combines the helical vertical lift capability with the speed and range of a conventional fixed wing aircraft. For the vertical flight, the rotor is tilted so that the horizontal rotation field, lifting the rotor helicopter way. As the speed of the aircraft increases, the rotor is progressively tilted forward, with the rotation plane finally becoming vertical. In this wing mode the elevator provides, and the rotor provides a boost as a propeller. Because the rotor can be configured to be more efficient for propulsion (eg with root rotation) and avoid helicopter problems by stopping the saw blades, tiltrotor can reach higher speeds than helicopters.
A tiltrotor plane is different from tiltwing where only the pivot rotor than the entire wing. This method trades in-flight vertical efficiency for efficiency in STOL/STOVL operations.
Video Tiltrotor
Histori
The idea of ​​building a Take-Off and a Vertical Landing (VTOL) aircraft using helicopter-like rotors on the wing tips originated in the 1930s. The first design that resembled modern tiltrotor was patented by George Lehberger in May 1930, but he did not develop this concept further. In World War II, the German prototype, Focke-Achgelis Fa 269, was developed beginning in 1942, but never flew. Platt and LePage patented PL-16, the first American tiltrotor aircraft. However, the company closed in August 1946 due to lack of capital.
The two flying prototypes are the Transcendental Model 1-G one and two seat Transcendental Model 2, each powered by a single reciprocating engine. Construction began in Model 1-G in 1947, although it did not fly until 1954. The 1-G model flew for about a year until an accident at Chesapeake Bay on July 20, 1955, destroyed the prototype plane but did not seriously injure the pilot. Model 2 was developed and flew shortly afterwards, but the US Air Force withdrew funds to support Bell XV-3 and did not fly far beyond hover tests. Transcendental 1-G is the first flying tiltrotor plane and completes most of the helicopter transition to an aircraft (within 10 degrees of horizontal aircraft flight).
Built in 1953, the experimental Bell XV-3 flew to 1966, proving the fundamental health of the tiltrotor concept and gathering data on the technical improvements required for future design.
The development of related technology is tiltwing. Although two designs, the Canadair CL-84 Dynavert and the LTV XC-142, are a technical success, not going into production due to other problems. Tiltrotor generally has better hover efficiency than tiltwings, but less of a helicopter.
In 1968, Westland Aircraft featured their own designs - a small experimental aircraft (We 01C) and a 68-seater We 028 transport - at the SBAC Farnborough Airshow.
In 1972, with funding from NASA and the US Army, Bell Helicopter Textron began the development of XV-15, a twin-engined tiltrotor research aircraft. Two planes were built to prove the tiltrotor design and explore operational flight envelopes for military and civilian applications.
In 1981, using the experience gained from XV-3 and XV-15, Bell and Boeing Helicopters began developing the V-22 Osprey, a twin-turboshaft military tiltrotor for the US Air Force and the US Marine Corps.
Bell worked with Boeing in developing commercial tiltrotor, but Boeing came out in 1998 and Agusta got into Bell/Agusta BA609. The aircraft was redesigned as AW609 after the transfer of full ownership to AgustaWestland in 2011. Bell also developed the unmanned aerial vehicle tiltrotor (UAV), Eagle Eye TR918.
Russia has had several tiltrotor projects, mostly without crew like Mil Mi-30, and has started another in 2015.
Around 2005-2010, Bell and Boeing are working together again to conduct a conceptual study of the larger Quad TiltRotor (QTR) for the US Armed Forces Combined Force (JHL) joint program. QTR is a four-rotor version larger than the V-22 with two fixed wing wings and four tilted rotor.
In January 2013, the FAA established a US tiltrotor noise rule to comply with ICAO rules. A noise certification would cost $ 588,000, just as for a large helicopter.
AgustaWestland says they have flown manned electric tiltrotor in 2013 called Project Zero, with its rotor in wingspan.
In 2013, Bell Helicopter CEO John Garrison responded to Boeing who took different fuselage partners to the US Army's improved requirements in the future by showing that Bell would lead itself in developing Bell V-280 Valor, with Lockheed Martin.
In 2014, Clean Sky 2 (by the EU and industry) awarded AgustaWestland and its $ 328 million partners to develop next generation "civil design tiltrotor" designs for the offshore market, with Critical Design Review near the end of 2016. The targets are the tilt wing , 11 tons of maximum takeoff weight, seating for 19 to 22 passengers, first flight in 2021, 300 knot cruise speed, top speed of 330 knots, 25,000 ft ceiling, and a range of 500 nautical miles.
Maps Tiltrotor
Technical considerations
Control
In vertical flight, the tiltrotor uses controls that are very similar to twin or tandem-rotor helicopters. Yaw is controlled by tilting its rotor in the opposite direction. The winding is provided through differential power or impulse. Pitch is provided through cyclic rotor or nacelle tilt. The vertical motion is controlled by a conventional rotor blade pitch and either a conventional helicopter collective control lever (as in Bell/Agusta BA609) or a unique control similar to a fixed-wing engine control called a TCL (as in Bell-Boeing V- 22 Osprey).
Speed ​​and payload issues
The advantage of a tiltrotor is a much larger speed than a helicopter. In a helicopter, the maximum forward speed is determined by the rotation speed of the rotor; at some point the helicopter will move forward at the same rate as the spinning from the reverse side of the rotor, so that the rotor side sees zero or negative air velocity, and begins to gain time. This limits modern helicopters to cruising speeds of around 150 knots/277 km/h. However, with the tiltrotor this problem is avoided, since proprotors are perpendicular to movement at high speed portions of the flight regime (and thus are not subject to this reverse condition), so the tiltrotor has a relatively high maximum speed - over 300 knots/560 km/hr has been shown in two types of flown tiltrotors thus far, and a cruising speed of 250 knots/460 km/h is achieved.
This speed is achieved at the expense of the load. As a result of this reduced charge, some estimate that the tiltrotor does not exceed the transport efficiency (speed of charge time) of the helicopter, while others conclude otherwise. In addition, the tiltrotor propulsion system is more complex than conventional helicopters because the nacelles are articulated large and the wings are added; however, increased shipping efficiency and increased speed over helicopters are significant in certain uses. Speed ​​and, more importantly, the benefits to the overall response time are the main virtues sought by military forces using tiltrotor. Tiltrotor is inherently less noisy in forward flight (airplane mode) than helicopters. These, combined with their increased speed, are expected to increase their utility in populated areas for commercial use and reduce the threat of detection for military purposes. Tiltrotors, however, are usually as loud as the same-sized helicopters in flying flight. The noise simulation for the 90 passenger tiltrotor shows lower cruise noise in the cabin than the Bombardier Dash 8 aircraft, although low-frequency vibrations may be higher.
Tiltrotor also provides the ability of a cruise ship altitude far greater than a helicopter. Tiltrotor can easily reach 6,000 m/20,000 ft or more whereas helicopters usually do not exceed 3,000 m/10,000 ft altitude. This feature will mean that some commonly considered uses only for fixed wing aircraft can now be supported with tiltrotors without requiring grounding. The disadvantage, however, is that tiltrotors suffer heavy loads during takeoff from high altitudes.
Mono tiltrotor
A mono tiltrotor plane uses a tilted spinning propeller, or a coaxial proprotor , for lifting and propulsion. For a vertical flight, the proprotor is tilted to steer his thrust downwards, providing an elevator. In this mode of operation, craft is basically identical to a helicopter. As the plane grew faster, the coaxial proprotters slowly tilted forward, with the blades finally becoming perpendicular to the ground. In this wing mode the elevator provides, and greater wing efficiency helps the tiltrotor reach high speeds. In this mode, this plane is basically a turboprop aircraft.
A mono tiltrotor plane differs from a conventional tiltrotor in which the proprotors are fitted to the wingtips, where the coaxial proprotor is fitted to the plane. As a result of this structural efficiency, the mono tiltrotor exceeds the transport efficiency (load speed time) of both helicopters and conventional tiltrotor. One design study concluded that if mono tiltrotor could be technically realized, it would be half the size, one-third the weight, and almost twice as fast as the helicopter.
In the vertical flight, mono tilting uses a very similar control to coaxial helicopters, such as the Kamov Ka-50. Yaw is controlled for example by increasing the lift on the upper proprotor while lowering the lift on the lower proprotor. Rolls and pitchs are provided through the cyclic rotor. Vertical motion is controlled by conventional rotor blade blade.
List of aircraft tiltrotor
- AgustaWestland AW609
- AgustaWestland Project Zero
- American Dynamics AD-150
- Bell XV-3
- Bell XV-15
- Bell Eagle Eye
- Bell V-280 Valor
- Bell-Boeing V-22 Osprey
- Curtiss-Wright X-19
- Focke-Achgelis Fa 269
- IAI Panther
- Transcendental 1-G Model
Also see
- Refresh field
- Tiltjet
- Tiltwing
- Tailsitter
- VTOL
- Snapshots
Reference
External links
- "Unmanned TiltRotor Hybrid TRH-14". Artamonoff technology. Ã,
- Jean-Claude Cailliez (June 1, 2006). "L'invention du premier Tiltrotor de l'histoire par les frÃÆ'¨res Henri et Armand Dufaux (1907-09)". Les pionniers de l'aÃÆ'Â © ronautique ÃÆ' GenÃÆ'Âve (in French).
- AeroSpaceNews (December 25, 2012). Tilt Rotor History . YouTube.
- Richard Ward (April 6, 2018). "Long Road to Tiltrotor". AIN .
Source of the article : Wikipedia
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