Military Review

Tiltrotor of the future Bell HSVTOL

50

Three variants of tiltrotor HSVTOL in virtual flight


In early August, Bell Textron announced the HSVTOL (High-Speed ​​Vertical Take-Off and Landing) project, the goal of which is to create a whole family of convertiplanes based on common solutions. The aircraft of the new line will be able to take off and land vertically, and develop high speed in horizontal flight. Several interesting ideas and technologies are proposed for solving such technical problems.

A forward-looking concept


The concept project HSVTOL proposes the creation of an aircraft architecture with the ability to scale for different tasks. In the published materials, three versions of the tiltrotor have already been shown - from a small-sized unmanned vehicle to a cargo vehicle in the dimensions of a C-130 aircraft. In addition, Bell is working on various additional systems, such as offshore platforms to support the operation of the UAV.

In all cases, the HSVTOL tiltrotor is a machine with a streamlined fuselage and a mid-wing, on the tips of which nacelles with propellers are placed. The tail is provided with a two-keel plumage. The main turboshaft / turbojet engine should be located in the upper or tail part of the fuselage, which is responsible for the rotation of the propellers and the creation of a jet stream in different flight modes.

It is assumed that the HSVTOL will take off vertically using two rotors. By turning the gondolas in the vertical plane, he will be able to switch to horizontal flight. For acceleration to maximum speeds, it is proposed to use jet thrust and wing lift; the propeller blades should be folded along the nacelles.


Airfield equipment

As stated, this scheme can be used to build aircraft of various sizes, carrying capacities and purposes. According to calculations, it is possible to exceed the flight speed of 400 knots (740 km / h). However, each project of the family will actually have to be developed separately using units and structures that correspond to the terms of reference.

In early August, Bell revealed only the alleged appearance of the new convertiplanes and some of their characteristics. The other day more has become known about the project: on September 10, The Drive, under the heading The War Zone, published an interesting article on this topic. In it, Jeff Nissen, Head of Advanced Technologies at Bell, spoke about stories development of convertoplanes and disclosed new data on the current project HSVTOL.

General approaches


The main task of the HSVTOL project is to achieve the maximum possible speed and range of flight. According to these parameters, the new samples should surpass the existing tiltrotors. For this purpose, some studies were carried out, during which the optimal level of flight performance was determined.

It has been established that the aircraft of the new scheme must develop a cruising speed of at least 400 knots. With less high speed requirements, you can use the "traditional" tiltrotor scheme, using propellers in all modes. The maximum speed should not exceed 0,85 M (more than 1000 km / h depending on the altitude). After exceeding this value, a significant increase in air resistance is expected. It can be overcome by increasing the thrust of the "sustainer" engine, but this will degrade fuel efficiency and reduce the possible range.


Medium modification of HSVTOL in rescue operation

The calculated maneuverability of HSVTOL is higher than that of other converters. A light or medium vehicle will be able to make vigorous evolutions and fly around the terrain. However, achieving maneuverability at the level of modern fighters is impossible.

The tiltrotor glider is being designed with a reduction in visibility in mind, but its architecture and exterior limit the achievable results in this area. The ability to fold the propellers removes one of the main unmasking factors, however, even in this mode, the aircraft will be more noticeable than specially designed stealth aircraft.

Together with the tiltrotor, Bell is working on the basing issues. For example, UAVs of the HSVTOL family can be used with the Sea-based Logistics Unmanned Refuel / Re-arm Platform (SLURRP). The device will be able to land on such a platform, automatically refuel and rise again into the air. The medium aircraft can be used with larger platforms, crewed or autonomous.

Engine question


The main task of the HSTOVL project is to find the optimal power plant architecture. Bell is currently working on several options based on existing and future components. Some versions allow for the fastest possible bringing the project to testing, but limit the technical characteristics. Other schemes allow obtaining high flight data, but they are complex and require additional elaboration.


Lightweight UAV on the SLURRP platform

The simplest approach is proposed to be implemented in a light UAV project. Such a device should receive a "lifting" TVD with a transmission to both propellers and a "sustainer" turbojet engine. This scheme allows the development and testing of a prototype vehicle as quickly as possible using engines available on the market. However, it does not differ in weight efficiency and limits the overall level of performance.

For larger variants of HSVTOL, combined schemes are proposed, in which flight in all modes will be provided by one engine or several with the required total power. Calculations have already shown that the HPT will not give the required characteristics in the two main modes of operation, and therefore a different solution is needed.

At the theoretical level, the Pratt & Whitney F135 engine with a lift fan, developed for the F-35B fighter, was considered. For all its advantages, it shows insufficient traction and, at least, needs improvement. A hybrid scheme is being studied, in which the turbojet engine is connected to a generator, and the main rotor is rotated by an electric motor. This option is of interest, but so far it cannot show high fuel or weight efficiency.


Experienced Bell V-280 Valor tiltrotor - one of the fastest in its class

The best option is considered a multi-mode gas turbine engine capable of alternately delivering more power to the shaft and creating high reactive thrust. However, products of this class have not yet advanced beyond testing, and the development of a new model will take an indefinite time. Therefore, in the short and medium term, Bell plans to study and develop only available products.

Oncoming flow


The propeller design developed for HSVTOL is of great interest. During the transition to high-speed flight, the apparatus must feathered the blades and then lay them along the gondola. The optimal design of such a propeller was created and tested back in 1972 and has shown all its advantages.

Folding of the blade is carried out by means of a hinge in the butt part. There are no drives. The blade should change its position only due to the incoming air flow. In this case, a braking system is provided that controls the speed of movement of the blades.


Serial tiltrotor MV-22 is landing on an aircraft carrier

Tests in the early seventies showed the possibility of performing 30-40 folding and unfolding cycles at speeds of 150-175 knots (280-325 km / h) without interruption. Probably, the further development of the project, as well as the use of modern materials and technologies will ensure the operability of the original circuit and at 400 nodes.

Theory and practice


Thus, the HSVTOL project is still in its earliest stages, involving the development of basic ideas and the search for technical solutions. At the same time, the construction and testing of experimental equipment is still a matter of an uncertain future - while the developer company has to assess the real prospects of the project and determine the feasibility of its continuation.

As follows from official statements and messages, Bell Textron is optimistic about the future, and it is not just a desire to demonstrate its interest in promising developments. The company has extensive experience and expertise in vertical takeoff aircraft. In addition, new ideas and concepts are constantly being put forward, studied and put into operation. On the basis of old experience and modern proposals, they can really create a technique of a new class - or even a whole family.

However, excessive optimism is hardly appropriate. The proposed HSVTOL concept faces several serious problems, without solving which it will not be possible to create a tiltrotor with the required level of performance. In the near future, Bell Textron and related organizations will have to resolve all these issues - and then it will become clear what the tiltrotor of the future will be.
Author:
Photos used:
Bell Textron Inc., US Navy
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  1. rocket757
    rocket757 14 September 2021 18: 07
    +8
    Serious technique, difficult.
    The work of design ideas at a high level.
    1. Ross xnumx
      Ross xnumx 14 September 2021 18: 33
      +10
      Quote: rocket757
      The work of design ideas at a high level.

      This is much more entertaining than attempts to recreate the An-2.
      Even in "Avatar" something similar flashed ... The idea is very interesting.
      1. rocket757
        rocket757 14 September 2021 18: 59
        0
        One does not interfere with the other ... while there is a lot of work for the technique of classical designs. It is simpler and more convenient in many respects.
        1. Flooding
          Flooding 14 September 2021 19: 07
          0
          Quote: rocket757
          One does not interfere with the other ... while there is a lot of work for the technique of classical designs. It is simpler and more convenient in many respects.

          I wonder how the tiltrotor will behave when one of the engines fails
          1. Mitroha
            Mitroha 14 September 2021 19: 16
            +3
            Quote: Flood
            I wonder how the tiltrotor will behave when one of the engines fails

            I guess it will land abnormally, vhlam
            1. Flooding
              Flooding 14 September 2021 19: 19
              0
              Quote: Mitroha
              I guess it will land abnormally, vhlam

              maybe the propeller of a failed engine switches to free rotation (like a gyroplane)?
            2. sailor roman
              sailor roman 14 September 2021 19: 56
              -5
              As of 2021, 48 convertiplanes were built and put into operation in the United States; over the past 10 years, due to the failure of one of the engines, there have been catastrophes and accidents of about two dozen US convertiplanes and 3-4_x in Japan.
              1. OgnennyiKotik
                OgnennyiKotik 14 September 2021 20: 08
                +5
                Quote: sailor Roman
                As of 2021, 48 convertiplanes were built and put into operation in the USA

                Forgotten zero.
                On June 11, 2020 it was delivered 400 pieces.
                A very successful and useful aircraft, with the last crash in 2017. On aircraft carriers, he became the main transport worker.
                https://www.aerospacemanufacturinganddesign.com/article/bell-boeing-delivers-400th-v-22-osprey/
          2. rocket757
            rocket757 14 September 2021 19: 22
            -3
            Probably those who flew in it at that moment, it was no longer interesting, after a couple of three minutes!
          3. Avior
            Avior 14 September 2021 19: 52
            +10
            inside the wing at Osprey there is a shaft that allows one engine to work on both propellers. Valor, as far as I understand, has a similar design, especially since it is simpler there - the engines do not turn.
            Two Rolls-Royce AE 1107C V-22 engines are driven by drive shafts to a common central gearbox, so that one engine can drive both engines in the event of engine failure. [75] Either engine can drive both propellers through the propeller shaft of the wing.

            Of course, this mode also has limitations - the load on the remaining engine will double.
  2. Lad
    Lad 14 September 2021 18: 47
    +2
    The best option is considered a multi-mode gas turbine engine capable of alternately delivering more power to the shaft and creating high reactive thrust.

    A promising thing.
  3. Saxahorse
    Saxahorse 14 September 2021 19: 14
    -4
    Doubtful idea however. Hybrids with several types of drives always turn out to be either completely flawed or at least ineffective. And here, for takeoff and landing, there is one type of propulsion device, and it is rather complicated. And for horizontal movement it is completely different.
    1. ProkletyiPirat
      ProkletyiPirat 14 September 2021 20: 03
      +1
      Quote: Saxahorse
      Hybrids with several types of drives always turn out to be either completely flawed or at least ineffective.

      ) mining dump trucks, no?
      ) construction machinery with hydraulic drive, no?
      ) Submarines in general and submarines in particular, not?
      ) diesel locomotives on the railway, no?
      Conclusion: do not be nonsense, the whole point of negatives is in the jambs of the development team, and not hybridity in itself.
      1. Saxahorse
        Saxahorse 14 September 2021 20: 35
        +2
        Quote: ProkletyiPirat
        ) mining dump trucks, no?

        Do mining trucks have a separate power unit for lifting the body and a separate one for turning the wheels?

        Do not confuse warm and soft. One thing is a single power plant delivering power to different drives, and another thing is a set of separate independent power plants for moving in different directions .. Then immediately questions about efficiency begin.
        1. ProkletyiPirat
          ProkletyiPirat 15 September 2021 19: 16
          +1
          Quote: Saxahorse
          Quote: ProkletyiPirat
          ) mining dump trucks, no?

          Do mining trucks have a separate power unit for lifting the body and a separate one for turning the wheels?

          Depends on the specific model.

          Quote: Saxahorse
          Do not confuse warm and soft. It's one thing to have a single power plant delivering power to different drives, and another thing is a set of separate independent power plants for moving in different directions.

          That's right, don't be confused, there is only one side of the movement, but there are several modes of movement, it turns out like an airplane has one aircraft engine and several "propulsion (operating modes)": a turbine propeller (or a turbo-fan propeller (here not turbo screw)); turbo-jet propulsion and afterburner-jet propulsion. So in HSVTOL there is only one engine, but several movers. But in any case it does not matter, since you initially: firstly) confuse the concept of engine (SU), drive and mover; and secondly) you do not understand and confuse the difference between the terms "type of technology", "concept of technology", "sample of technology", "copy of technology", you, everything that relates to the sample and the instance, you ascribe to the type and / or concept ...
          1. Saxahorse
            Saxahorse 15 September 2021 20: 40
            +1
            Judging by the abundance of terms, you yourself are confused. meanwhile, nothing complicated, a mover is something that directly sets an object in motion, for example, a propeller, caterpillars, wheels, legs .. The power plant is what supplies the mover with energy. For a propeller, this is a steam engine, a turbine, a diesel generator. In Boeing, in this scheme, we see four propellers of two different types, each of which has its own, built-in power plant. The turbofan at the wing, turbojet at the tail. Moreover, this does not work together, only one by one in different driving modes. On takeoff, the turbojet dead weight, in the horizontal theater of operations, fold and represent a dead weight. Therefore, it is ineffective. For the military, it may work, but only for a niche product, such as a taxi for special forces. Already for an ordinary military transport, the weight loss for extra engines will be considered excessive.
            1. ProkletyiPirat
              ProkletyiPirat 15 September 2021 23: 30
              0
              ahh, so that's what, but where did you get your idea that there are different engines (SU)? As I understand it, new control systems based on gas turbine engines are used that use both a power take-off shaft and a jet propulsion, similar to how it is implemented in the F-35, that is, there is no parasitic mass you voiced, and even if there is, it is not essential, because the voiced one itself you, the principle is false, and the military refuse not because of the extra mass in itself, but either because of the deterioration of the old tactical and strategic capabilities, or for the sake of obtaining new tactical and strategic capabilities (and yes, we do not confuse TTX, TTV and TSV).
    2. xASPIDx
      xASPIDx 14 September 2021 23: 22
      +2
      The whole problem in the complexity of the design and the price is not entirely correct, but when solving all the problems, you get equipment with the parameters of several units in one, and from this point of view, the costs are lower. One single device is cheaper and easier to maintain than two or more, but this is the prerogative of those who have the technology and finances to solve the problems that arise, but the advantages of such devices are significant.
      1. Saxahorse
        Saxahorse 15 September 2021 20: 42
        +1
        Quote: xASPIDx
        the whole problem is in the complexity of the design and the price, but when solving all problems, you get equipment with the parameters of several units in one

        Here's an argument from the post above:
        On takeoff, the turbojet dead weight, in the horizontal theater of operations, fold and represent a dead weight. Therefore, it is ineffective. For the military, it may work, but only for a niche product, such as a taxi for special forces. Already for an ordinary military transport, the weight loss for extra engines will be considered excessive.
    3. Maxim G
      Maxim G 16 September 2021 11: 01
      +2
      Here, in general, the question is whether these tiltrotors are needed in principle, or whether there are enough helicopters.
      Nobody except the USA is in a hurry to build them serially.
  4. vovochkarzhevsky
    vovochkarzhevsky 14 September 2021 19: 27
    -8
    From the point of view of aerodynamics, the tiltrotor is a dead-end branch. A very complex design with low weight-bearing capacity and overestimated horizontal flight power requirements.
    But they are perfect for cutting a budget.
    1. ProkletyiPirat
      ProkletyiPirat 14 September 2021 20: 12
      +3
      Quote: vovochkarzhevsky
      From the point of view of aerodynamics, the tiltrotor is a dead-end branch.

      another sofa expert, for those who do not understand anything in aerodynamics I chew: ALL helicopters, during horizontal flight, spend part of their fuel not on acceleration, and not on flight, but on braking, and the higher the speed of horizontal flight, the greater the percentage of fuel is spent on aircraft braking, this braking occurs when the blades move forward against the incoming air flow, and it is this shortcoming that tiltrotors solve. Everything else refers to the jambs of specific aircraft and the teams that develop them, and not tiltrotors as a type of technology.
      1. vovochkarzhevsky
        vovochkarzhevsky 14 September 2021 20: 34
        +4
        I quite agree that you are a couch expert. That is why you are talking about the mythical braking of the blades. What is oblique blowing of HB, Zhukovsky curves, you certainly have not heard.
        I'm sorry, but I somehow understand this better.
        By the way, the limitation of the horizontal flight speed is not at all due to the advancing, but retreating blades, when the reverse flow zone grows with increasing speed.
    2. Avior
      Avior 14 September 2021 20: 22
      +5
      Compare Grumman C2 and Osprey.
      The Americans are changing the transport aircraft on their carriers from C2 to Osprey.
      Not only is it not inferior in terms of parameters, but even surpasses in some, moreover, it is capable of landing on ships and ships without a take-off deck, and not only on aircraft carriers. It is very convenient for logistics - for direct delivery without reloading from supply vessels or UDC, for example.
      1. vovochkarzhevsky
        vovochkarzhevsky 14 September 2021 21: 54
        -6
        Of course it surpasses, it eats more kerosene, more dangerous in flight. Actually, they took it into service more in order to show the world, like, that's what magician.
        1. Avior
          Avior 14 September 2021 23: 32
          +1
          Compare Grumman C2 and Osprey.

          And if you do not throw cliches and cliches, but take and really compare?
          Internal fuel, kg 6282 + optionally 7427 in additional tanks
          Cruising speed, km / h 510
          Practical range, km 3892
          Payload: 24 soldiers or 9072 kg of cargo in the cab
          The last disaster 2017


          Internal fuel, l 6905 + optional 5519
          Cruising speed, km / h 465
          Practical range, km 2891
          Payload: 28 passengers or 12 stretchers with an accompanying person or 4536 kg of cargo in the deck version or 6804 kg of cargo in the ground version
          The last disaster 2017

          hi
          1. Maxim G
            Maxim G 16 September 2021 12: 12
            0
            How correct is it to compare airplanes whose start of operation is dozens of years apart?
            1. Avior
              Avior 16 September 2021 13: 48
              +1
              Is Osprey an airplane?
              1. Maxim G
                Maxim G 16 September 2021 14: 10
                0
                Well, you are comparing it to an airplane.
                How he goes through the documents, I do not know.
                1. Avior
                  Avior 16 September 2021 14: 59
                  0
                  From the fact that I compare some of its characteristics with an airplane, it does not become an airplane. Again, I don’t know of any other carrier-based transport aircraft currently in use, so there’s nothing to compare with.
                  Before the appearance of Osprey, the Americans were satisfied with the C-2, it met their requirements, so it is quite logical to compare with him.
                  You read the beginning of the branch, what is it about?
                  1. Maxim G
                    Maxim G 16 September 2021 15: 21
                    0
                    I read it - and you apparently did not pay attention to what Vladimir Ivanovich wrote to you).
                    1. Avior
                      Avior 16 September 2021 16: 57
                      +1
                      I even paid attention to what you wrote, not just him
                      How correct is it to compare airplanes whose start of operation is dozens of years apart?

                      Compare with other modern deck cargo
                      hi
    3. xASPIDx
      xASPIDx 14 September 2021 23: 29
      +2
      I'll tell you a terrible secret, but if you have the necessary engine and suitable body materials, the aircraft can even have the shape of a brick. The main thing is that the engines have the necessary thrust for takeoff and movement and a body that could withstand external influences.
  5. KCA
    KCA 14 September 2021 19: 45
    -7
    They advertise with fanfare, but something American Marines refuse to fly on envelopes, prefer helicopters
  6. Alien From
    Alien From 14 September 2021 20: 29
    +1
    The Union was never able to make such a technique in reality.
    1. vovochkarzhevsky
      vovochkarzhevsky 14 September 2021 21: 57
      0
      There is simply no need for it, that's all. The USA cannot create a helicopter of the Mi-26 type.
      1. OgnennyiKotik
        OgnennyiKotik 14 September 2021 23: 10
        +1
        Quote: vovochkarzhevsky
        There is simply no need for it, that's all. The USA cannot create a helicopter of the Mi-26 type.

        Quite the opposite. The United States did not even try to create an analogue of the Mi-26, with its geographical location, it is absolutely meaningless. But ours tried, in addition to various rotary-wing aircraft of the Ka-22 type, there were tiltrotor projects, for example, the Mi-30.
        1. not main
          not main 14 September 2021 23: 27
          +1
          Quote: OgnennyiKotik
          Exactly the opposite.

          Compare the dates ... and it will become clearer for you!
        2. VasYok
          VasYok 15 September 2021 19: 11
          0
          there were tiltrotor projects, for example, the Mi-30.

          My God, 1972! It's been 50 years, and NO FUCK!
          In principle, "NO FUCK" is the norm of our life. It's time to get used to it.
        3. vovochkarzhevsky
          vovochkarzhevsky 15 September 2021 23: 28
          +1
          Well, yes, of course it's pointless. bully
      2. Avior
        Avior 14 September 2021 23: 51
        0
        helicopter type Mi-26

        Sikorsky CH-53K King Stallion

        Maximum lifting capacity - up to 15900 kg.
        hi
        1. vovochkarzhevsky
          vovochkarzhevsky 15 September 2021 23: 37
          -1
          Vkryaty three engines, without really having a cargo compartment and by draining the fuel, the Americans were able to create something comparable to the Mi-6, which had long been removed from service.
          By the way, according to American standards, the carrying capacity of the Mi-6 is 20117 kg. This is his record.
          1. Avior
            Avior 16 September 2021 07: 12
            0
            For the Mi-6, the maximum carrying capacity was 11,5 tons for a short distance.
            The Americans did not make a helicopter for records, but for their own tasks.
            Like the Mi-26, as you wrote.
            hi
            1. vovochkarzhevsky
              vovochkarzhevsky 16 September 2021 11: 00
              0
              Is it news for you that Americans like to indicate record data?
              CH-53K has an empty weight of 15070 kg, while the maximum take-off weight is 33600 kg.
              Total: 33600 - 15070 - 15900 = 2630 kg, in which, in addition to fuel, you need to stuff a lot more.
              Therefore, further they so modestly indicate: the combat radius with a nominal load of 12,25 tons is 200 km.
              1. Avior
                Avior 16 September 2021 11: 20
                +1
                and what of that?
                you wanted
                helicopter type Mi-26

                here he is for you
                hi
      3. Maxim G
        Maxim G 16 September 2021 12: 23
        +1
        Vladimir Ivanovich, why don't you write an article about helicopters or the same UAVs (I read your comments about Turkish drones) - the topic is relevant and the detailed opinion of a professional military pilot and veteran would be very interesting?
    2. Lepsik
      Lepsik 14 September 2021 22: 55
      -3
      The USSR had a more promising project - the Caspian monster and its analogues.
      1. Alien From
        Alien From 14 September 2021 23: 00
        +3
        Tiltrotor and ekranoplan ... like yin and yang ...
  7. Hog
    Hog 15 September 2021 13: 08
    +2
    An interesting concept using one engine in two different modes, as a result, only propellers in the "airplane" mode become ballast, and not whole engines, as in other concepts.
  8. Kushka
    Kushka 15 September 2021 13: 50
    +2
    Quote: xASPIDx
    The whole problem in the complexity of the design and the price is not entirely correct, but when solving all the problems, you get equipment with the parameters of several units in one, and from this point of view, the costs are lower. One single apparatus is cheaper and easier to maintain than two or more.
    With the advent of the smartphone, we got a talker, a newspaper reader, a watchdog, a musician, a novigalka, a payer, a rewriter, a photographic camera, a film snapshot, a micro PC and, if desired, a beer opener (soon, apparently, there will also be a function of a T-shirt) But nevertheless, in the apartment, all the listed units have a place to be and, accordingly, all hemorrhoids (+ a million wires) connected with them. The poor cat was left with a small corner on the floor.
    С