Hybride d'helicoptère et d'avion

[g4lly]

http://blog.wired.com/defense/2008/12/the-quest-for-t.html

The Quest for the 300-m.p.h. Helicopter

Speedhawk1This year marked the passing of Frank Piasecki, one of the pioneers of rotary aircraft. Piasecki was perhaps best known as the man who successfully developed the first tandem-rotor helicopter, paving the way for long-serving military aircraft like the CH-47 Chinook and the CH-46 Sea Knight.

But Piasecki also backed compound helicopter concept, which would added vectored thrust and lifting wings to a conventional helicopter design to boost its speed, range and agility. The Piasecki X-49 "Speedhawk" -- an experimental helicopter based on a Sikorsky YSH-60F Seahawk -- first flew in 2007. The "ring tail" helicopter incorporated Piasecki's vectored-thrust ducted propeller and other modificiations.

The Speedhawk was funded by the Army to test the possibility of pushing existing helicopters to reach speeds up to 200 knots (360 kilometers per hour). But Piasecki is not the only outfit chasing after record helicopter speeds. Challis Heliplane has also forwarded a concept for the "world's fastest" rotorcraft. The Challis Heliplane would feature a single fixed wing on the retreating blade side of the aircraft of the aircraft that would provide extra lift at high airspeeds. And Bell Helicopter, maker of the military's fast-flying Osprey tiltrotor, has already debuted a civilian version of the hybrid aircraft, which can go twice as fast as a normal helicopter.

[Invité BPCs]

Ensuite si l'affaire se fait il y aurait l'option de ceci :

US Army contract to develop a compound helicopter incorporating the Piasecki Vectored Thrust Ducted Propeller (VTDP) concept for the AH-64 Apache and AH-1W SuperCobra is nearing completion. Programme objectives have been met or exceeded by both the AH-64 VTCAD and AH-1W VTCAD configurations, resulting in increased maximum level flight speed to over 370km/h; 50% improvement in longitudinal acceleration and deceleration capability in level flight; 50% decrease in turn and pull-up radius at speeds in excess of 175km/h; and handling qualities that are at least as good as those of the baseline AH-64 Apache and AH-1W SuperCobra. In addition, tactical simulations have confirmed superiority of VTCAD over standard Apache and AH-1W SuperCobra. A separate US Navy contract involves investigation into application of VTDP technology to the AH-1W(4BW) four-blade rotor configuration. The Navy contract also includes ground testing of the full-scale VTDP and additional flight controls simulation and testing of the 4BW/VTDP configuration. Piasecki has also proposed flight demonstration of this technology on an AH-1W(4BW) to the Navy.

On imaginerait avec plaisir la même chose vers 2020 pour nos Tigres (enfin arrivés...)

[Invité BPCs]

Une autre option technique pour arriver à augmenter la vitesse des hélicos :

In the ULOR concept a fixed wing attached to the rotor hub generates lift, unloading the rotor and allowing higher speed.

http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3afbf422c7-8568-41f8-87e2-2b3e5c5f806a

[chimère]

Une autre option technique pour arriver à augmenter la vitesse des hélicos :

In the ULOR concept a fixed wing attached to the rotor hub generates lift, unloading the rotor and allowing higher speed.

http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3afbf422c7-8568-41f8-87e2-2b3e5c5f806a

Je pense que Philippe appréciera cette version...  :lol:

[FATac]

Perso, le concept ULOR ne m'apparait comme une fausse bonne idée.

Certes, plus la vitesse augmente, et plus le rotor est déchargé du rôle de portance par l'aile, ce qui lui permet de rester dans un rôle de propulsion.

Cependant, aux petites vitesses, la portance reposera entièrement sur le(s) rotor(s), et la déformation des pales (assez souples, quand même) sera maximale, avec un risque réel de collision en bout de disque (les ailes étant, elles, déchargées, et donc fléchies sous leur propre poids).

En outre, les interaction aile/rotor, au niveau de l'écoulement, me paraissent difficile à maitriser. Déjà, en plein ciel, j'ai du mal à concevoir, mais alors dans un effet de sol, avec réflexion du flux sur celui-ci ... ce qui arrive souvent, dans la vie d'un hélicoptère ...

Je ne suis pas sûr du tout que ce concept aille plus loin que la planche à dessin ou la CAO - sans parler des aspects encombrement, maintenance, fonctionnement, fiabilité car j'imagine que les opérationnels vont vouloir replier ces ailes (comme le rotor), et qu'il faudra une solution fiable pour les déplier et verrouiller avant le vol, que ça va ajouter un poids non négligeable en tête de rotor, etc ...

Vous l'aurez compris, je suis plus que dubitatif ...

[Philippe Top-Force]

Je pense que Philippe appréciera cette version...  :lol:

Je ne vois pas ce qui te fait dire cela  :lol:

[g4lly]

Perso, le concept ULOR ne m'apparait comme une fausse bonne idée.

Certes, plus la vitesse augmente, et plus le rotor est déchargé du rôle de portance par l'aile, ce qui lui permet de rester dans un rôle de propulsion.

Cependant, aux petites vitesses, la portance reposera entièrement sur le(s) rotor(s), et la déformation des pales (assez souples, quand même) sera maximale, avec un risque réel de collision en bout de disque (les ailes étant, elles, déchargées, et donc fléchies sous leur propre poids).

On te mettra les ailes en dessous des pales si tu preferes ;)

En outre, les interaction aile/rotor, au niveau de l'écoulement, me paraissent difficile à maitriser. Déjà, en plein ciel, j'ai du mal à concevoir, mais alors dans un effet de sol, avec réflexion du flux sur celui-ci ... ce qui arrive souvent, dans la vie d'un hélicoptère ...

Je ne suis pas sûr du tout que ce concept aille plus loin que la planche à dessin ou la CAO - sans parler des aspects encombrement, maintenance, fonctionnement, fiabilité car j'imagine que les opérationnels vont vouloir replier ces ailes (comme le rotor), et qu'il faudra une solution fiable pour les déplier et verrouiller avant le vol, que ça va ajouter un poids non négligeable en tête de rotor, etc ...

Vous l'aurez compris, je suis plus que dubitatif ...

Moi aussi mais chut ;)

[Invité BPCs]

On te mettra les ailes en dessous des pales si tu preferes ;)

Comme sur celui-ci ? :lol: :lol: :lol:

              65-07992, Boeing build number B-164, was a CH-47A helicopter. The U.S. Army acceptance date was 24 February 1966. The administrative strike date was 11 April 1975. 65-07992 accumulated 734.0 aircraft hours. 65-07992 was part of the Heavy Lift Helicopter (HLH) Program. Boeing Vertol developed the experimental BV-347 to test various concepts and components for use on future heavy lift helicopters. The prototype model 347 was a converted CH-47A and made its first flight during 1972. The aircraft was extensively modified and featured a nine foot two inch stretch in the main cabin, retractable landing gear, four bladed rotors which were longer than the standard CH-47D blades by two and one half feet, and a raised aft pylon. The most unusual modification was the provision for a wing which could be mounted on the top center fuselage to augment the lift from the rotors. The prototype was fitted with an advanced fly-by-wire control system and was powered by updated Lycoming T55-L-11 engines giving it a maximum speed exceeding 180 knots. After the prototype completed the test program during 1975, it was retired. 65-07992 was transferred to the Army Aviation Museum located at Fort Rucker, Alabama. As of 1 January 2002, this aircraft was 35.8 years old. As of 15 September 2001, the last known location of 65-07992 was at Fort Rucker, Alabama. Aircraft status: Museum exhibit.

http://www.chinook-helicopter.com/history/aircraft/A_Models/65-07992/65-07992.html

[g4lly]

Voilà :) y a plus qu'a mettre une truboreacteur quelques part les helice en drapeau et vroom vroom en avant pour mach 2 :lol:

modele A


modele B

@BPCs si tu te demande pourquoi j'ai remis tes photos ... c'est juste que tu les as holinkées et qu'elle ne s'affiche que si aurparavant tu a visité ton lien et quel sont donc dans ton cache...

[Invité BPCs]

Et sans mettre des stato réacteurs il y a déjà eu le modèle 360 :

qui poussait jusqu'à 370 km/h sans rajout d'ailes pour décharger les rotors : en combinant le modèle 347 et ce modèle 360 on se dit que le concept chinook a pas mal de potentiel d'évolution...

" First flown in 1987 the Model 360 is a privately developed advanced technology rotorcraft, designed to research the company's other rotorcraft programs. The helicopter features advanced aerodynamics and extensive use of composite materials including the fuselage, rotor shafts, blades and hubs. Powered by twin Avco-Lycoming AL5512 engines (4200shp) the Model 360 has a 370km/h cruise speed. The aircraft's advanced cockpit features cathode ray tube displays, multi-function callouts, digital automatic flight control system and other improvements to reduce pilot workload."

[Invité BPCs]

Les essais tant du sikorsky X2 que du  VTDP de Piasecki va peut être remettre au présent des projets européens comme celui ci :

Lynx ACH: Advanced Compound Helicopter.

Technology demonstrator project, publicly announced 22 May 1998 and due to begin in 1999, partly funded by UK MoD. Target is 50% speed increase by means of wings attached at cabin roof level and variable area exhaust nozzles; additional thrust derived from RTM322 turboshafts in place of Gems (uprated gearbox taken from W30-200); BERP rotor blades; flaps on wing trailing-edges, with pitching moment neutralised by all-moving tailplane; and trimming rudder to reduce tail rotor loads.

Performance will include maximum level speed of 463km/h; ceiling of 6,100m; 20% additional payload/range; 50% more propulsive efficiency; and between 25 and 50% improvement in lift/drag ratio.

[LBP]

http://www.flightglobal.com/Assets/GetAsset.aspx?ItemID=931

http://www.flightglobal.com/articles/1998/05/27/37545/westland-prepares-compound-helicopter-demonstrator.html

[Chronos]

N'empêche avec l'autonomie d'un chinook ça peut faire une sacrée plateforme d'armement  un hélo avec des ailes pareilles.

[Invité BPCs]

http://www.flightglobal.com/Assets/GetAsset.aspx?ItemID=931

http://www.flightglobal.com/articles/1998/05/27/37545/westland-prepares-compound-helicopter-demonstrator.html

[g4lly]

First Pusher Prop Ground Runs Conducted Successfully For Sikorsky's X2 TECHNOLOGYT Demonstrator

07:33 GMT, February 3, 2009 Stratford, Connecticut | Sikorsky Aircraft Corp. achieved a major milestone in its X2 TECHNOLOGYTM demonstrator program by successfully ground testing the aircraft with the pusher propeller installed and spinning for the first time. Sikorsky is a subsidiary of United Technologies Corp. (NYSE:UTX).

The test conducted Jan. 23 used the fly-by-wire pitch control system with the rotating, high-speed pusher propeller for the first time. The program testing has been continuing at Sikorsky's Schweizer Aircraft Corp. rapid-prototyping facility in Horseheads, N.Y., since the demonstrator's first flight on Aug. 27, 2008.

"The high-speed pusher prop produced the expected amount of thrust and the testing went according to plan," said Steven Cizewski, X2 Program Manager. "In addition, the pusher prop's drive system and oil distribution system checked out well. In all, we are pleased with this milestone and look forward to finishing the tests in Elmira, N.Y., as we prepare to move the demonstrator into its next phase of testing in West Palm Beach."

Sikorsky Vice President of Research & Engineering Mark Miller said, "This ground test milestone effectively completes Phase I of the four-phase X2 TECHNOLOGY development test program."

"We are looking forward to completing the remainder of the envelope expansion phases, and achieving 250 knots at the completion of Phase IV by the end of the year," Miller said.

The X2 TECHNOLOGY demonstrator combines an integrated suite of technologies intended to advance the state-of-the-art, counter-rotating coaxial rotor helicopter. It is designed to demonstrate a helicopter can cruise comfortably at 250 knots, while retaining such desirable helicopter attributes as excellent low speed handling, efficient hovering and autorotation safety, and a seamless and simple transition to high speed.

Among the innovative technologies the X2 TECHNOLOGY demonstrator employs are:

• Fly-by-wire flight controls

• Counter-rotating rigid rotor blades

• Hub drag reduction

• Active vibration control

• Integrated auxiliary propulsion system

Sikorsky Aircraft announced its initiative to develop an integrated suite of technologies called X2 TECHNOLOGY in June 2005. The project is funded solely by Sikorsky.

[Cassius]

Je ne vois pas trop l'intérêt de cette technologie par rapport au tilt rotor d'un BA 609.

Est-elle mieux adaptée aux petits aéronefs ? (ici c'est juste un biplace)

[g4lly]

Je ne vois pas trop l'intérêt de cette technologie par rapport au tilt rotor d'un BA 609.

Est-elle mieux adaptée aux petits aéronefs ? (ici c'est juste un biplace)

La sécurité ... le systeme fonctionne betement comme un helicoptere, en cas de panne moteur il reste l'autorotation, en cas de panne du pusher le systeme devient un helico simple.

Et la simplicité. Le rotor principal contrarotatif est une technologie maitrisé depuis longtemps ... le pousseur a helice aussi.

Enfin la transition vol poussé / vol tiré semble etre tres facile du moins c'est ce qu'affirme Sikorsky. Les convertible on des soucis aerodynamique  de vitesse de descente... ca a été réglé dans les manuels de vol mais visiblement il y sont bien plus sensible que les helo classique.

[Cassius]

Ok, merci pour ces précisions  =)

Envisagent-ils des hybrides plus grands ?

[g4lly]

DARPA Gives DiscRotor a Whirl

It appears DARPA is scaling back ambitions for the Heliplane gyroplane program while taking a closer look at another high-speed rotorcraft concept. The agency has awarded Boeing a $7.35 million contract for Phase 1 of the DiscRotor risk-reduction study. The DiscRotor is a compound helicopter with a rotating circular wing that can extend and retract rotor blades depending on the phase of flight.

DARPA thinks the DiscRotor should be capable of 400kt-plus at 30,000ft, while retaining the hover and low-speed characteristics of a helicopter. The rotor blades are extended for vertical flight and gradually retracted and stowed during the transition from helicopter to aeroplane mode. The disc is stopped and acts as a circulation-control wing in forward flight.

Under Phase 1, according to earlier DARPA documents, Boeing's advanced rotorcraft folks in Philadelphia will conduct windtunnel tests of a small-scale manually extendable rotor followed by a larger automatically operated system. The focus will be on the transition between rotor- and disc-borne flight. Boeing and teammate Virginia Tech conducted concept definition studies under a previous phase.

Boeing has experience with circulation control from its work on the ultimately unsuccessful X-50A Dragonfly Canard Rotor/Wing demonstrator. A first glance, it looks like it might be easier to get the DiscRotor to work than the stopped-rotor X-50. And what about Heliplane, DARPA's previous best bet for high-speed VTOL?

No-one is saying anything yet, but while DARPA has awarded Georgia Tech a contract for the next phase of the program it looks likely a flying demonstrator is no longer on the cards. Last July the agency announced plans to shift leadership of the program from struggling Groen Brothers and award Georgia Tech a contract to close the design and experimentally demonstrate the ability to to control the VTOL gryoplane at speeds up to 400mph.

That is likely to involve a windtunnel test of the rotor system. A key goal will be to demonstrate the reaction-drive rotor can meet tip-jet noise requirements. This is an area where Georgia Tech came to Groen's aid during Phase 1 of program, which was extended six months to give the team more time to come up with a new design for the blade-tip jets. DARPA thinks they did - the tests will tell.

[g4lly]

Could Unmanned Express Delivery Suit Sikorsky's X2?

Sikorsky has begun turning the tail-mounted propeller on its X2 Technology demonstrator, in preparation for high-speed flight tests, but there are no signs yet of a near-term application for the 250kt-cruise coaxial-rotor helicopter.

But the Office of Naval Research (ONR) has issued a request for information on a cargo unmanned aircraft system that might just fit the X2. ONR is looking for a vertical takeoff and landing UAV that can operate from U.S. Navy ships to support geographically dispersed U.S. Marine Corps combat units. It wants a vehicle that can carry at least 1,600lb of payload over a radius in excess of 285nm at a cruise speed of at least 250kt. ONR is seeking ideas for vehicles that could be fielded within 5 years, 5-10 years and 10-15 years.

Sikorsky plans to demonstrate the X2's 250kt cruise capability by year-end, so it could be a near-term contender. Getting the prop turning is a key step along the way. For the three-flight initial low-speed test phase late last year the variable-pitch prop was disconnected. On the demonstrator, the prop now is directly connected to the main transmission, so it turns when the rotors turn. But a production X2 would have a clutch, so that the prop could be disconnected on the ground and when its thrust is not needed.

The prop's pitch-change mechanism is now connected to the X2's fly-by-wire system. The next step is to add the rotor-hub fairings and gear-retraction mechanism to reduce drag. Then the X2's forward-flight envelope will be opened up in three phases: from 40kt to 120kt will use rotor thrust; 120-180kt will use a combination of rotor and prop thrust; 180kt upwards will use the prop, with the rotor producing only lift at maximum speed.

[Bruno]

Je crois que le X2 de sikorsky pourrait donner naissance à un excellent appareil d'appui-feu sur des theâtre comme l'Afghanistan. Evidemment il faudrait appliquer la même formule (double rotor contrarotaztif + hélice propulsive) à un appareil au fuselage bien plus gros pour qu'il y ait davantage de capacité carburant et la place d'emporter des paniers de roquettes, missiles Hellfire ou Spike ...

[Berkut]

Si tu veux, Kamov vend le Ka52 Alligator  :lol:

[Invité BPCs]

Si tu veux, Kamov vend le Ka52 Alligator  :lol:

Voire le "Erdogan" avec la dispo biplace tandem.

Mais l'on reste avec une limitation d'hélico autour de 300 km/hpour ce qui est de la vitesse de pointe sans atteindre les 360-460 revendiqués dans les projets d'hybrides (qui ramènent à la vitesse d'un OV-10 ou d'un V-22)

[Berkut]

Je ne sais pas si le Erdogan aurait eu la protection d'un Alligator. Par contre monter un pousseur sur un Ka 52... Ca devrait donner une sacrée bête car le bébé file déjà à près de 350km/h.

blindage et vitesse avec une sacrée capacité de manœuvre. Le défaut étant peut être le canon qui est monté dans l'axe du fuselage et non sur un tourelleau sous le nez

[Invité BPCs]

Je ne sais pas si le Erdogan aurait eu la protection d'un Alligator. Par contre monter un pousseur sur un Ka 52... Ca devrait donner une sacrée bête car le bébé file déjà à près de 350km/h.

blindage et vitesse avec une sacrée capacité de manœuvre. Le défaut étant peut être le canon qui est monté dans l'axe du fuselage et non sur un tourelleau sous le nez

oui mais en  piqué, sinon 310 comme le tigre