Controlled thrust vector
Thrust vector control (PVC) jet engine - deviation of the jet stream of the engine from the direction corresponding to the cruising mode.
At present, thrust vector control is provided mainly by turning the entire nozzle or part of it.
Fig. 1: Schemes of nozzles with mechanical UVT: a) - with flow deflection in the subsonic part; b) - with flow deflection in the supersonic part; c) - combined.
The scheme with flow deflection in the subsonic part is characterized by the coincidence of the mechanical deflection angle with the gas dynamic angle. For a scheme with deviation only in the supersonic part, the gas-dynamic angle differs from the mechanical one.
Fig. 2: Scheme of a nozzle with a CGWT using atmospheric air in the axial flow mode: 1-power flow; 2-ejected control flow of the atmosphere; 3-ring shell fixed on dividing ribs; 4-separating ribs.
Fig. 3: Scheme of a nozzle with a GUVT in the maximum thrust vector deflection mode: 1-closed sector; 2-open sector; 3-region of low pressure.
The gas dynamic nozzle uses a "jet" technique to change the effective area of the nozzle and deflect the thrust vector, while the nozzle is not mechanically adjustable. This nozzle does not have hot, highly loaded moving parts, it fits well with the aircraft design, which reduces the mass of the latter.
The outer contours of the fixed nozzle can smoothly fit into the contours of the aircraft, improving low visibility performance. In this nozzle, air from the compressor can be directed to the injectors in the critical section and in the expanding part to change the critical section and control the thrust vector, respectively.
Links
- RD-133 - on airwar.ru
Literature
- Bezverby V.K., Zernov V.N., Perelygin B.P. The choice of design parameters of aircraft .. - M .: MAI., 1984.
- No. 36 // Express information. Series: aviation engine building .. - M .: CIAM., 2000
- Krasnov N.F. Aerodynamics. 2 // Aerodynamics. Methods of aerodynamic calculation. - M.: VSh, 1980.
- Shvets A.I. Aerodynamics of load-bearing forms. - Kyiv: VSH, 1985.
- Zalmanzon L.A. Theory of the elements of pneumonics. - M.: Nauka, 1969. - S. 508.
- 2 // Experience in creating a gas-dynamic thrust vector control device. Abstracts. Kuznetsova", 2001. - S. 205-206.
Or parts of it.
Encyclopedic YouTube
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The first experiments related to the practical implementation of a variable thrust vector on aircraft date back to 1957 and were carried out in the UK as part of a program to create a combat aircraft with vertical takeoff and landing. The prototype, designated P.1127, was equipped with two 90° rotating nozzles located on the sides of the aircraft on the center of gravity line, which provided movement in vertical, transitional and horizontal flight modes. The first flight of the R.1127 took place in 1960, and in 1967, the first serial Harrier VTOL aircraft was created on its basis.
A significant step forward in the development of engines with a variable thrust vector in the framework of VTOL programs was the creation in 1987 of the Soviet supersonic VTOL Yak-41. The principal distinguishing feature of this aircraft was the presence of three engines: two lifting and one lifting-mid-flight with a rotary nozzle located between the tail booms. The three-section design of the lift-main engine nozzle made it possible to turn down from a horizontal position by 95 °. \
Expansion of maneuvering characteristics
Even during the work on R.1127, the testers noticed that the use of a deflectable thrust vector in flight somewhat facilitates the maneuvering of the aircraft. However, due to the insufficient level of technology development and the priority of VTOL programs, serious work in the field of increasing maneuverability due to OBT was not carried out until the end of the 1980s.
In 1988, on the basis of the F-15 B fighter, an experimental aircraft was created with engines with flat nozzles and thrust vector deviation in the vertical plane. The results of the test flights showed the high efficiency of the OBT for improving the controllability of the aircraft at medium and high angles of attack.
Approximately at the same time, in the Soviet Union, an engine with an axisymmetric deflection of a circular section nozzle was developed, work on which was carried out in parallel with work on a flat nozzle with a deflection in the vertical plane. Since the installation of a flat nozzle on a jet engine is associated with a loss of 10-15% of thrust, preference was given to a round nozzle with an axisymmetric deviation, and in 1989 the first flight of the Su-27 fighter with an experimental engine took place.
Operating principle
The scheme with flow deflection in the subsonic part is characterized by the coincidence of the mechanical deflection angle with the gas dynamic angle. For a scheme with deviation only in the supersonic part, the gas-dynamic angle differs from the mechanical one.
The design of the nozzle circuit shown in rice. 1a, must have an additional assembly that provides the deflection of the nozzle as a whole. Scheme of a nozzle with flow deflection only in the supersonic part on rice. 1b in fact, it does not have any special elements to ensure the deflection of the thrust vector. The differences in the operation of these two schemes are expressed in the fact that in order to provide the same effective angle of deflection of the thrust vector, the scheme with a deflection in the supersonic part requires large control torques.
The presented schemes also require solving the problems of ensuring acceptable weight and size characteristics, reliability, resource and speed.
There are two thrust vector control schemes:
- with control in one plane;
- with control in all planes (with all-aspect deviation).
Gas-dynamic thrust vector control (GUVT)
High efficiency thrust vector control can be achieved using gas dynamic thrust vector control (GUVT) due to the asymmetric supply of control air to the nozzle path.
The gas dynamic nozzle uses a "jet" technique to change the effective area of the nozzle and deflect the thrust vector, while the nozzle is not mechanically adjustable. This nozzle does not have hot, highly loaded moving parts, it fits well with the aircraft design, which reduces the mass of the latter.
The outer contours of the fixed nozzle can smoothly fit into the contours of the aircraft, improving the characteristics of constructive low visibility. In this nozzle, air from the compressor can be directed to the injectors in the critical section and in the expanding part to change the critical section and control the thrust vector, respectively.
The formation of control forces is provided by the following order of operations.
- In the first phase of the nozzle (Fig. 5) increase the angle of deflection of the flaps of the expanding part of the nozzle - the angle α installation of the exit doors of the expanding part 3 nozzles.
- In the second phase (Fig. 6), in the mode of formation of control forces on a part of the surface of the nozzle, the dampers are opened 8 for the entry of atmospheric air on part of the side surface of the expanding part of the nozzle 3 . On fig.6 view shown A and direction of inflow of atmospheric air through open holes with flaps on part of the side surface. Damper switching 8 on the opposite half of the lateral expanding part of the nozzle leads to the deflection of the jet and the thrust vector of the engine at an angle β in the opposite direction.
To create control forces in an engine with a supersonic nozzle, you can slightly change the supersonic part of an existing nozzle. This relatively uncomplicated modernization requires a minimum change in the main parts and assemblies of the original, regular nozzle.
When designing, most (up to 70%) of the components and parts of the nozzle module may not be changed: the attachment flange to the engine body, the main body, the main hydraulic drives with attachment points, levers and brackets, as well as critical section doors. The designs of superstructures and spacers of the expanding part of the nozzle are changed, the length of which increases, and in which holes with rotary dampers and hydraulic drives were made. In addition, the design of the outer doors changes, and the pneumatic cylinders for them are replaced by hydraulic cylinders, with a working pressure of up to 10 MPa (100 kg / cm 2).
Rejected thrust vector
Rejected thrust vector (OBT) - function of the nozzle, changing the direction of the outflow of the jet. Designed to improve the tactical and technical characteristics of the aircraft. Adjustable jet nozzle with a deflectable thrust vector - a device with variable, depending on the engine operating modes, the dimensions of the critical and outlet sections, in the channel of which the gas flow is accelerated in order to create jet thrust and the possibility of deflecting the thrust vector in all directions.
Application on modern aircraft
Currently, the thrust vector deflection system is considered as one of the essential elements of a modern combat aircraft due to the significant improvement in flight and combat qualities due to its use. The issues of modernizing the existing fleet of combat aircraft that do not have OVT are also being actively studied by replacing engines or installing OVT units on regular engines. The second option was developed by one of the leading Russian manufacturers of turbojet engines - the Klimov company, which also produces the world's only serial nozzle with an all-aspect thrust vector deviation for installation on the RD-33 engines (family of MiG-29 fighters) and AL-31F (Su brand fighters).
Combat aircraft with thrust vector control:
With axisymmetric deviation of the thrust vector
- Su-27SM2 (engine AL-31F-M1, Product 117S)
- Su-30 (AL-31FP engine)
- PAK FA (prototype)
- F-15S (experimental)
Today, VTOL aircraft are no longer a curiosity. Work in this direction began in the main in the mid-1950s and went in a variety of directions. In the course of development work, aircraft with turning installations and a number of others were developed. But among all the developments that provided vertical takeoff and landing, only one has received worthy development - a system for changing the thrust vector using jet engine rotary nozzles. At the same time, the engine remained stationary, the Harrier and Yak-38 fighters, equipped with similar power plants, were brought to sulfur production.
However, the idea of using rotary nozzles to provide vertical takeoff and landing has its roots in the mid-40s, when within the walls of OKB-155, headed by chief designer A.I. Mikoyan, on an initiative basis, a project for such an aircraft was developed. Its author was Konstantin Vladimirovich Pelenberg (Shulikov), who worked in the Design Bureau from the day it was founded.
It is worth noting that back in 1943 K.E. Pelenberg also, on his own initiative, developed a project for a fighter with a short takeoff and landing. The idea of creating such a machine was caused by the desire of the designer to reduce the take-off distance in order to ensure combat work from front-line airfields damaged by German aircraft.
At the turn of the 30s - 40s, many aircraft designers paid attention to the problem of reducing the takeoff and landing distance of an aircraft. However, in their projects, they tried to solve it by increasing the wing lift using various technical innovations. As a result, a wide variety of designs appeared, some of which reached prototypes. Biplanes with a retractable lower wing in flight (IS fighters designed by V.V. Nikitin and V.V. Shevchenko) and monoplanes with a wing that expands in flight (RK aircraft designed by G.I. Bakshaev) were built and tested. In addition, the most diverse mechanization of the wing was submitted for testing - retractable and flapping slats, various kinds of flaps, split wings and much more. However, these innovations could not significantly reduce the takeoff and run distance.
In his project, K. V. Pelenberg focused not on the wing, but on the power plant. During the period 1942-1943. he developed and carefully analyzed several fighter schemes that used a change in the thrust sector due to deflected propellers to reduce takeoff and travel. The wing and plumage in these cases only helped to achieve the main task.
The fighter developed as a result was a monoplane of a two-beam scheme, having a three-wheeled landing gear with a front support. Spaced beams connected the wing with the tail unit, which had an all-moving stabilizer. The main landing gear was located on the beams, small arms and cannon weapons were located in the forward fuselage.
The power plant was located in the aft fuselage behind the cockpit. Power through a gearbox and elongated shafts was transmitted to paired pusher propellers, which had mutually opposite rotation. The latter eliminated the reactive moment and increased the efficiency of the propeller group.
During takeoff and landing, the twin propellers, with the help of a hydraulic drive, could be turned down relative to the axis of the gearbox, thereby creating a vertical lifting force. The two-beam scheme fully contributed to the free movement of the propellers, while in the deflected position they were slightly obscured by the fuselage and wing. When approaching the ground or when flying near it, the propellers were supposed to form an area of compacted air under the aircraft, creating the effect of an air cushion. At the same time, their efficiency also increased.
Naturally, when turning the screws from the longitudinal axis down, a dive moment arose, but it was parried in two ways. On the one hand, the deflection of the all-moving stabilizer, operating in the zone of active blowing of the propellers, by a negative angle. On the other hand, the deflection of the wing console in the plane of the chord forward at an angle corresponding to the balancing conditions for a given direction of the thrust vector. With the transfer of the aircraft to level flight after rising to a safe height, the propellers turned to their original position.
In the case of the implementation of this project, the proposed fighter could have a very short takeoff distance, but for a vertical takeoff, the power that existed at that time was clearly not enough. Therefore, for such a project, in order to reduce take-off and landing distances, as well as take-off and landing along a steep trajectory close to vertical, one high-power motor or two were required that worked synchronously on one shaft.
Designed by K.B. Pelenberg’s fighter project is interesting in that it used propeller thrust with great efficiency to create additional lift for the aircraft and aerodynamic balancing means unusual for that time - a movable wing or, as it is now called a variable geometry wing, as well as a controlled stabilizer. It is interesting to note that these and some other technical innovations proposed by the designer in this project were largely ahead of their time. However, in the future they found a worthy application in the aircraft industry.
The short takeoff and landing fighter project remained a project, but it only reinforced the author's desire to create a vertical takeoff and landing aircraft. Konstantin Vladimirovich understood that the possibility of vertical takeoff opened up invaluable tactical opportunities for military aviation. In this case, the aircraft could be based on unpaved airfields, using areas limited in size, and on the decks of ships. The urgency of this problem was already clear then. In addition, with the growth of the maximum flight speeds of fighters, their landing speeds inevitably grew, which made landing difficult and unsafe, in addition, the required length of the runways increased.
At the end of the Great Patriotic War, with the appearance in our country of captured German jet engines YuMO-004 and BMW-003, and then the Dervent-V, Nin-I and Nin-II engines purchased from the English company Rolls-Royce, it was possible to successfully solve many problems in the domestic jet aircraft industry. True, their power was still insufficient to solve the task, but this did not stop the work of the aircraft designer. At this time, Konstantin Vladimirovich not only worked in the design bureau of the chief designer A.I. Mikoyan, but also taught at the Moscow Aviation Institute.
To the development of a fighter with vertical takeoff and landing, in which a turbojet engine (TRD) was used as a power plant, K.V. Pelenberg started at the beginning of 1946 on his own initiative, and by the middle of the year the project of the machine was generally completed. As in the previous project, he chose a scheme with a fixed power plant, and vertical takeoff provided a variable thrust vector.
A feature of the proposed scheme was that the cylindrical nozzle of the jet engine ended in two symmetrically divergent channels, at the end of which nozzles were installed rotating in a vertical plane.
A significant advantage of the proposed device was the simplicity of design, the absence of the need to modify the nozzle of the engine itself and the comparative ease of control. At the same time, the rotation of the nozzles did not require more effort and complex devices, as, for example, in the case of changing the thrust vector by rotating the entire power plant.
The fighter developed by Konstantin Vladimirovich was a monoplane with a modified engine layout. The most powerful at that time English Nin-II turbojet engine with a thrust of 2270 kgf was supposed to serve as a power plant. The air supply to it was carried out through the frontal air intake. When laying out the machine, one of the main requirements was that the axis of the thrust vector, when the nozzles were deflected, passed near the center of gravity of the aircraft. The nozzles, depending on the flight mode, had to be rotated to the most favorable angles ranging from 0 to 70 °. The largest nozzle deflection corresponded to the landing, which was planned to be carried out at the maximum engine operation. The change in the thrust vector was also supposed to be used to decelerate the aircraft.
Meanwhile, due to the placement of the power plant at an angle of 10-15° relative to the fighter's horizontal line, the range of nozzle deviation from the engine axis ranged from +15° to -50°. The proposed design fits well into the fuselage. Appropriate rotation and inclination of the plane of rotation of the nozzles made it possible not to spread them too far from each other. In turn, this made it possible to increase the diameter of the channels - this rather critical parameter was optimized taking into account the midsection of the fuselage so that the channels fit into its dimensions.
Technologically, both channels connected to the fixed part, together with the rotation control mechanism, were one unit, which was connected to the cylindrical engine nozzle with the help of a flange. The nozzles were attached to the ends of the channels with the help of thrust bearings. In order to protect the movable joint from exposure to hot gases, the edges of the nozzle blocked the slot of the rotation plane. Forced cooling of the bearings was organized by taking air from the atmosphere.
To deflect the nozzles, it was planned to use a hydraulic or electromechanical drive mounted on the fixed part of the nozzle, and a worm gear with a gear sector fixed on the nozzle. The power drive was controlled either by the pilot remotely or automatically. The equality of the angles of rotation was achieved by the simultaneous activation of the drives. Their control was synchronized, and the limiting angle of deviation was fixed by a limiter. The nozzle was also equipped with guide vanes and a casing designed to cool it.
Thus, the gas jet has become a fairly powerful means of providing vertical takeoff and landing. Its use as a landing aid for a fighter with an engine thrust of about 2000 kgf reduced the wing area so much that it could actually be turned into a control organ. A significant reduction in the dimensions of the wing, which at large numbers M, as is known, constitutes the main drag of the aircraft, made it possible to significantly increase the flight speed.
Acquainted with the project. A.I. Mikoyan advised K.V. Pelenberg to register it as an invention. On December 14, 1946, the relevant documents were sent to the Bureau of Inventions of the Ministry of Aviation Industry. In the application, sent along with an explanatory note and drawings entitled “Turnable Jet Nozzle”, the author asked to register this proposal as an invention “to secure priority”.
Already in January 1947, a meeting of the expert commission at the technical department of the MAP was held under the chairmanship of the candidate of technical sciences V.P. Gorsky. The commission also included A.N. Volokov, B.I. Cheranovsky and L.S. Kamennomostsky. In its decision of January 28, the commission noted that this proposal was correct in principle and recommended that the author continue to work in this direction. Along with this, she noted that reducing the wing area is inappropriate, since in the event of a power plant failure, the landing of the aircraft will be problematic.
Soon, the aircraft project received a constructive study to such an extent that it gave the author grounds for its consideration in TsAGI, CIAM, Design Bureau of Plant No. 300 and other organizations, where the project also received a positive assessment. As a result, on December 9, 1950, K.V. Pelenberg was accepted for consideration by the Office for Inventions and Discoveries under the State Committee for the Introduction of Advanced Technology in the National Economy. At the same time, the publication of the proposed invention was prohibited.
Of course, the project did not yet cover and could not immediately cover all the subtleties associated with the creation of a vertically taking off aircraft. Especially since I had to work alone. But although there were many technical difficulties and new problems, even then it became clear that the project was real, that it was the beginning of a new direction in modern aviation.
The rotary nozzle alone did not solve all the problems that arise during vertical takeoff. As stated in the decision of the IAP expert commission,
"...when the direction of the gas jet changes, the stability and balance of the aircraft will change, which will cause difficulties in control during takeoff and landing."
Therefore, in addition to changing the thrust vector, it was necessary to solve the issue of stabilizing the machine, since in the absence of blowing the wing and tail unit with air flow, they no longer performed the role of stabilizers.
In order to solve this problem, Konstantin Vladimirovich worked out several stabilization options. Firstly, the imbalance of the aircraft during the deviation of the thrust vector in flight can be parried by changing the angles of attack of the stabilizer. Secondly, at low flight speeds, he proposed the use of an additional jet device (autonomous or using exhaust gas from the compressor part of the engine). Work on the second method was the most difficult task, since without research and blowing in a wind tunnel it was impossible to judge the behavior of the aircraft with a deflected gas jet near the ground.
The fact is that when initial transverse disturbances occur near the ground, the angular accelerations of the wing rapidly increase, which lead to critical aircraft roll angles. With manual control of lateral stabilization, the pilot, for subjective reasons, does not have time to react in time to the appearance of an initial roll. As a result of the delay in the input of control, as well as a certain inertia of the system, manual control cannot guarantee a quick and reliable restoration of the disturbed transverse balance. In addition, the gas flow coming down from the jet engine, capturing adjacent air masses, causes air to flow from the upper surface of the wing to the lower one, which causes the pressure on top of the wing to increase and decrease below it. This reduces the lift force of the wing, worsens the damping and makes it difficult to stabilize the aircraft in roll. Therefore, in particular, the roll control required two to three times more sensitivity than the pitch control.
In this regard, in 1953 K.V. Pelenberg developed a lateral stabilization system for his VTOL fighter project. Its peculiarity was the use of two roll gyro stabilizers on the aircraft, which were placed on the wing (one in each console) at the maximum distance from the longitudinal axis of the machine. For their work, part of the energy of the gas jet of the turbojet engine was used. The system was put into operation with the help of gyroscopes, which are sensors of the stabilized position of the aircraft in roll and, at the same time, distributors of the direction of restoring reactive forces.
When the aircraft rolled, the gyrostabilizers created two equal reactive moments applied to the consoles and acting in the direction opposite to the roll. With an increase in the roll of the aircraft, the restoring moments increased and reached a maximum value when the maximum allowable roll angle was reached under safety conditions. Such a system had the advantage that it was put into action automatically, without the participation of the pilot and without intermediate connections, was inertialess, had high sensitivity and constant readiness for work, and also created conditions for aerodynamic damping of the wing.
Gyrogas stabilizers were put into operation in takeoff and landing modes simultaneously with the rotation of the main nozzles of the turbojet engine and the transfer of engines to vertical thrust. In order to stabilize the aircraft along all three axes, a pitch stabilization system was also put into operation at that moment. To turn on the roll stabilizers, the pilot opened the dampers located in the turbine part of the jet engine. Part of the gas flow, which had a speed of about 450 m / s in this place, rushed into the gas pipeline, and from there into the gyroblock, which directed it in the direction necessary for the roll to rise. When the flaps were opened, the upper and lower flaps automatically opened, covering the cutouts in the wing.
In the event that the aircraft wing occupied a strictly horizontal position relative to the longitudinal and transverse axes, the upper and lower windows of the right and left gyroblocks were open to half their size. Gas flows went up and down with equal speed, creating equal reactive forces. At the same time, the outflow of gas from the gyroblock upwards prevented the flow of air from the upper surface of the wing to the lower one, and, consequently, the rarefaction over the wing decreased when the engine thrust vector was deflected.
When a roll appeared, the gyrogas stabilizer damper on the lowered wing console reduced the gas output upwards and increased the gas output downwards, and the opposite happened on the raised console. As a result, a reactive force directed upwards increased on the descending console, and a restoring moment was created. On the raised wing console, on the contrary, the reactive force acting downwards increased, and an equal restoring moment arose, acting in the same direction. With a roll close to the maximum safe, the dampers of the gyroblocks opened completely - on the lowered console for the outflow of gas down, and on the raised one for the outflow of gas up, as a result of which two equal moments arose, creating a total restoring.
The main part of the developed stabilizer was a gyroscopic unit. Its front semi-axle was rigidly attached to the outer box, and the rear axle - to the gas receiver. The half shafts provided the gyroblock with free rotation relative to the axis, which, when installing the roll stabilizer in the wing, had to be placed strictly parallel to the longitudinal axis of the aircraft. In the plane of connection of the gas receiver with the gyroblock, there was a figured window, partially closed from below and from above by a damper. In this plane, the gyroblock and the receiver approached each other with a minimum gap, which ensured free rotation of the gyroblock. To avoid excess gas leakage, the docking plane had a labyrinth seal.
The receiver housed the gas distribution mechanism. Its role was to direct the gas flow from the line to the upper or lower chambers of the gyroblock, which then flowed out through the windows between the blades of the gyroblock disks. Depending on which direction the block turned, the damper closed either the upper window or the lower one, bypassing gas from the line to one of the chambers. During the operation of the gyroscope, the unit constantly maintained a horizontal position, and the rotation of the damper and the bypass of gas into the chambers occurred as a result of the rotation of the gas receiver relative to the transverse axis, caused by the tilt of the wing. The greater the bank angle, the more one window of the gyroblock opened and the other closed.
The gyroblock was installed in a rigid box, on which, with the help of hinges, two pairs of shields were fixed, covering the cutouts in the wing above and below. In the closed position, the flaps fit snugly against the slats and the rest of the wing surface, without disturbing its contour. They were also opened by the pilot simultaneously with the gas damper of the jet engine.
Gyrostabilizers were mounted in the wing consoles in such a way that the planes of the gyroscopes lay in the plane of the longitudinal and transverse axes of the aircraft. For airplanes of relatively small dimensions, which can have significant angles of oscillation in pitch, in order to avoid the phenomenon of gyroscope precession, it was supposed to introduce a parallelogram connection between the transverse axes of the right and left gyroblocks for their mutual retention.
According to calculations, the transverse stabilization of a vertical take-off fighter weighing 8000 kg with an aircraft thrust-to-weight ratio equal to one and a power takeoff of 3-4% from the turbojet engine could be provided by gyrostabilizers 2.25 m away from the longitudinal axis. At the same time, their diameter of 330 mm, height - 220 mm, outer box length - 350 mm, inner box width - 420 mm , diameter of the gas pipeline -142 mm, distances between the axes of the block and the gas pipeline - 295 mm. Such wing installations could create restoring moments of 100 kgm each at a bank angle of 10 °, and 220 kgm at a bank angle of 25-30 °.
However, this project of a vertical take-off and landing fighter at that time was not destined to be realized - it was also far ahead of the technical capabilities of that time. Yes, and the official circles reacted to him very skeptically. Since in the USSR the planned economy raised to the absolute meant, apparently, planned inventions, there were always not enough free working capital in design bureaus for their own large-scale R&D. Thus, the initiative project of a domestic VTOL aircraft remained on paper in the future.
Meanwhile, in the UK, the idea of developing a vertical take-off and travel jet aircraft (VTOL) was taken more seriously. In 1957, the Hawker Siddley company, on its own initiative, began to develop such an aircraft, and although there was also no experience in creating machines of this class, after only three years, the experimental fighter R. 1127 Kestrel took off. And six years later, an experienced Harrier attack aircraft was built on its basis - a prototype of the machines of the same name, now adopted not only by the British Royal Air Force, but also by other countries of the world.
In the Soviet Union, perhaps only in the LII, in practice, they studied the possibility of creating a vertical take-off and landing jet aircraft. In 1958 a group led by A.H. Rafaelants, developed and built an experimental apparatus, called the "Turbolet".
His flights proved the fundamental possibility of creating a jet-controlled aircraft in vertical take-off, hover and landing modes, as well as in the transition to horizontal flight. However, the idea of creating a vertical takeoff and landing aircraft had not yet captured the minds of the official authorities, although the “portfolio” of domestic designers included a project for such an aircraft, and the experience gained during the tests of the Turbolet.
Only at the end of 1960, when the R. 1127 Kestrel aircraft was already flying, and the first detailed publications about it appeared, official circles seemed to “break through”. The Central Committee of the CPSU and the Council of Ministers of the USSR thought seriously and decided once again to "catch up and overtake the decaying West." As a result, after almost a year of correspondence between all interested organizations, work on the design and construction of a vertical take-off and landing aircraft, on the basis of their joint Decree of October 30, 1961, was assigned to OKB-115 by the chief designer A.S. Yakovlev. The development of the power plant was entrusted to OKB-300 chief designer S.K. Tumansky. True, it is worth noting that back in 1959, Deputy Chairman of the Council of Ministers of the USSR D.F. Ustinov, Chairman of the State Committee for Aviation Engineering P.V. Dementiev and Commander-in-Chief of the Air Force SA K, A. Vershinin prepared a draft Decree, in which it was planned to entrust the design bureau of the chief designer G.M. Bernev.
In the autumn of 1962, the assembly shop left the first of three prototypes of the aircraft, called the Yak-Zb, intended for laboratory bench tests, on January 9, 1963, test pilot Yu.A. Garnaev performed the first hover on a leash on the second copy of the Yak-Z6, and on June 23 - free. YU.A. Garnaev was replaced by test pilot V.G. Mukhin, who on March 24, 1966 performed the first vertical takeoff and landing flight on the third experimental machine. As the power plant of the Yak-Zb, two R-27-300 turbojet engines equipped with rotary nozzle nozzles were used. Later, the experience of building and testing the Yak-36 experimental aircraft served as the basis for the creation of the combat VTOL Yak-38 (Yak-ZbM), which was mastered in mass production and was in service with the Navy aviation.
Meanwhile, on August 29, 1964 (18 years later!) The State Committee for Inventions and Discoveries issued K.V. Shulikov (Pelenberg) author's certificate No. 166244 for the invention of a jet engine rotary nozzle with priority dated December 18, 1946. However, at that time the USSR was not a member of the international organization for inventions and discoveries, and therefore this project could not receive worldwide recognition, since copyright applied only to the territory of the USSR. By this time, the design of the rotary nozzle had found practical application in aircraft engineering, and the idea of a vertically taking off aircraft was becoming widespread in world aviation. For example, the aforementioned English R.1127 Kestrel was equipped with a Pegasus turbojet engine with four rotary nozzles.
In October 1968, P. O. Sukhoi, in whose design bureau Konstantin Vladimirovich worked by that time, sent a request to S. K. Tumansky to pay remuneration to the author, since the enterprise headed by the latter mastered the serial production of jet engines with a nozzle device made according to the proposal of K.V. Shulikov scheme. As Pavel Osipovich noted in his address, in terms of its technical significance, this invention was one of the largest that was made in the field of aviation technology.
And on May 16, 1969, the appeal of P.O. Sukhoi was supported by A.A. Mikulin, who emphasized that the invention of K.V. Shulikov was considered by him back in 1947, and "regarded as a new, interesting technical solution, promising in the future a real prospect of using engine thrust to facilitate the take-off and landing modes of aircraft." In addition, by this time, on the VTOL project of 1946, positive conclusions were received from CIAM (No. 09-05 dated April 12, 1963, signed by V.V. Yakovlevsky), TsAGI (No. 8 years).
The application for the payment of remuneration for the invention of the rotary nozzle was considered at the meeting of the OKB-300 technical council held on October 10, 1969. During the discussion, it was noted that the proposed K.V. Shulikov, the rotary nozzle scheme was first introduced in the USSR on the R-27-300 engine (ed. 27), that is, its use made it possible to create the first domestic design of this class. In addition, this scheme was also developed by three developments of the P-27B-300 engine (ed. 49). In confirmation of this, the technical council 0KB-300 was presented with an act on the implementation of the invention according to copyright certificate No. 166244, which was drawn up by the head of the Design Bureau M.I. Markov and the responsible authorized BRIZ OKB I.I. Motin, The act noted that
Since the engines created according to this scheme were a new promising direction in the development of technology, the author's fee was determined in the amount of 5000 rubles. Thus, the technical council of OKB-300 recognized that the work of K.V. Shulikov formed the basis for the creation of the first domestic aircraft with vertical takeoff and landing.
With this in mind, the scientific and technical council of the IAP Technical Department chaired by IT. Zagainov in October 1969 considered lawful
"to recognize the priority in the technical development of the project of the first vertically taking off aircraft for domestic aviation technology."
Based on the great technical significance and prospects that this invention had, which anticipated the appearance of vertical take-off and landing aviation for many years to come, and the resulting superiority of domestic aviation in the development of this field of technology, the scientific and technical council assessed it as a technical improvement, close in its value to a technical discovery, and recommended paying the author the due remuneration.
This is a brief history of the world's very first project of a vertically taking off aircraft. And although the brainchild of an outstanding engineer and designer K.V. Shulikov in the Soviet Union did not find its embodiment in metal, this does not detract from the rights of the author and the domestic aviation science of technology to have priority in creating vertical take-off aviation.
In preparing the publication, documentary materials were used, kindly provided by K.V. Shulikov from his personal archive, as well as documents from the Russian State Archive of Economics.
Curriculum vitae
SHULIKOV (PELENBERG) Konstantin Vladimirovich
Konstantin Vladimirovich Shulikov (Pelenberg) was born on December 2, 1911, in the city of Pskov in the family of a military man. In 1939, he graduated with honors from the aircraft building department of the Moscow Aviation Institute with the qualification of a mechanical engineer. His practical activities in the aviation industry K.V. Shulikov began in 1937, combining work with studies at the institute. Being an employee of the design bureau of the chief designer N.N. Polikarpov, he went from a design engineer to the head of the wing sector of KB-1. Participated in the design and construction of the I-153 Chaika and I-180 fighters.
From December 1939 to 1951 K.V. Shulikov worked in the design bureau of the chief designer A.I. Mikoyan, where he took an active part in the development and construction of the MiG-1, MiG-3, I-250, I-270, MiG-9, MiG-15, MiG-17 fighters, the experimental MiG-8 "Duck" and other aircraft. In the spring of 1941, he was seconded as part of the brigade of plant No. 1 named after. Aviahim at the disposal of the Air Force of the Western Special and Baltic Special Military Districts to assist the flight personnel of combat units in mastering the MiG-1 and MiG-3 fighters. The task of the brigade also included the elimination of deficiencies identified during operation and the completion of the material part according to the bulletins of the manufacturer. During the Great Patriotic War, Konstantin Vladimirovich took part in the refurbishment of MiG-3 fighters, which were in service with the aviation regiments of the Air Force of the Western Front and the 6 IAK of Moscow Air Defense. In 1943, he developed a technology for the manufacture of soft fuel tanks.
In parallel with his work at OKB-155 in the period from 1943 to 1951, K. V. Shulikov concurrently conducted a lot of teaching work at the Moscow Aviation Institute, where he was a member of the Aircraft Design Department. He gave about 600 hours of lectures on aircraft design for 5th year students, he was also the head of graduation projects, a reviewer and took part in the development of teaching aids for students and graduate students.
In 1951, in accordance with the order of the MAP, Konstantin Vladimirovich was transferred to work at Aviastroyspectrest No. 5, and in 1955 - at the disposal of OKB-424 of Plant No. 81 MAP. In 1959, he moved to the Design Bureau of the General Designer S.A. Lavochkin, where he supervised the development and organization of the automatic guidance point for the Dal missile system at the Saryshagan training ground near Lake Balkhash. Since 1968 K.V. Shulikov continued his career in the Design Bureau of General Designer P.O. Sukhoi. He was an active participant in the development and construction of the T-4 supersonic missile-carrying aircraft.
From 1976 to 2003, Konstantin Vladimirovich worked at the Scientific and Production Association "Lightning" headed by G. E. Lozino-Lozinsky. He took part in the design and creation of the Buran reusable spacecraft, its analogue and experimental samples. Many of the technical solutions he proposed were accepted for development and production.
K.V. Shulikov owns a number of scientific works and more than 30 inventions in the field of aviation and astronautics. With his participation (jointly TsAGI, TsNII-30 MO, NII-2 MAP), research was carried out on the “Study of the aerospace complex of air launch of missiles”, including “Study of the appearance of the accelerating aircraft of the product “100” by V.N. Chelomey on the basis of the T-4 supersonic aircraft. He developed a project for a vertical take-off and landing aircraft, projects for various systems in the field of stabilization and controllability of aircraft, a project for a stabilizing platform for a high-altitude astronomical station of the USSR Academy of Sciences for lifting a large telescope weighing 7.5 tons into the stratosphere, a project for an inflatable ladder for the work of astronauts in open space, and others.
Ladoga-9 UV
Recently, he has developed projects for twin-engine multi-purpose amphibious aircraft "Ladoga-bA" for 6 seats and "Ladoga-9I" for 9-11 seats. In 1997, the Ladoga-bA amphibious aircraft project was awarded the Gold Medal at the Brussels-Eureka-97 World Exhibition.
To control the thrust vector in a solid propellant rocket engine, it is not advisable to mount the entire engine in the suspension (with the possible exception of vernier engines), therefore, at the disposal of designers
Rice. 117. Nozzle trimmers
the following solutions remain: installing mechanical control surfaces in the nozzle that deflect the gas jet, rotating the nozzle or part of it, secondary injection, and using additional control nozzles (similar to how it is done in a liquid-propellant rocket engine).
The mechanical control surfaces include, in addition to the gas rudders and deflectors discussed above, the sliding and rotary trim tabs shown in fig. 117. The effect of deflecting surfaces on the gas jet can be approximately calculated according to the theory of supersonic flow around the profile, but to obtain accurate values of the control force (the component of the thrust force perpendicular to the axis of the engine), depending on the magnitude of the deflection, measurements are necessary. It is reported in the paper that nozzles with such control of the gas jet make it possible to obtain, with good reproducibility, the maximum lateral forces reaching the axial thrust component. Despite the fact that the control of the thrust vector with the help of moving mechanical surfaces leads to loss of thrust due to additional resistance and requires painstaking research and development and technological work aimed at ensuring their strength and integrity under conditions of high dynamic pressures, temperatures and heat flows, they have been successfully used in such missiles as the Polaris and Bomark.
Rotary nozzles provide the most efficient mechanical control of the gas jet, since they do not cause a significant reduction in thrust and are competitive in terms of mass characteristics. One example of the use of such a technical solution is the assembly of four rotary nozzles with a gimbal suspension and a ball joint used on the first stage of the Minuteman rocket.
The system made it possible to control the thrust vector in the yaw, pitch and roll planes without noticeable loss of thrust, and the angle of deflection of the gas jet depended linearly on the rotation of the nozzle block.
Further improvement of thrust vector control methods is associated with more modern schemes that make it possible to exclude the use of gimbal suspension and moving hot metal parts placed in the solid propellant rocket nozzle. These schemes include: a) the Tehrol-type nozzle suspension system developed for solid propellant rocket engines of interorbital tugs (see Fig. 148 in Chapter 11); b) the thrust vector control system used in the engine of the booster module with a nozzle on a hinged suspension (see Fig. 150 in Chapter 11); c) used in the solid propellant booster VKS "Space Shuttle" mounting scheme of the nozzle on a flexible support. Let's consider the last scheme in more detail.
On fig. 118 shows the aft assembly of the TTU and shows the location of the units of the thrust vector control system, and in fig. 119 shows the device of the flexible nozzle connector. The connecting node is a shell made of a flexible elastic material with 10 steel ring gaskets of an arcuate section. The first and last reinforcing rings are attached to the fixed part of the nozzle, which is connected to the engine housing. Actuators of the rotary nozzle are powered by an auxiliary power unit. It consists of two separate hydraulic pump units that transfer hydraulic energy to the working servo cylinders, one of which ensures the rotation of the nozzle in the plane of sliding, and the other in the plane of the lateral turn (Fig. 120). If one of the units fails, the hydraulic power of the other is increased and it adjusts the deflection of the nozzle in both directions. Starting with the accelerator separation operation until it enters the water, the drives maintain the nozzle in a neutral position. The servo cylinders are oriented outward at an angle of 45° to the pitch and yaw axes of the aircraft. It should be noted that the auxiliary power unit that feeds the drives of the thrust vector control system in the solid propellant rocket engine under consideration runs on liquid single-component fuel - hydrazine, which is subjected to catalytic decomposition in the gas generator on a catalyst in the form of aluminum pellets coated with iridium.
10.3.1. SECONDARY INJECTION
A method for injecting an auxiliary working substance into the solid propellant rocket engine nozzle to control the thrust vector was proposed in the late 1940s. and began to be used in serial aircraft
machines in the early 1960s. Substances used for these purposes include inert liquids such as water and freon-113, as well as liquids that interact with hydrogen in combustion products and two-component fuels (for example, hydrazine
Rice. 121 illustrates the mechanism of influence of injection on the flow field in the nozzle. In addition to the fact that the injected liquid replaces part of the exhaust gases, the injection leads to the formation of a system of shock waves (separation shock and induced bow shock). The lateral component of the reactive force arises as a consequence of two effects: firstly, the momentum flux of the substance injected through
Rice. 118. (see scan) The lower assembly of the solid propellant booster VKS "Space Shuttle" - power cable (12 pcs.); 2 - support frame; 3 - thrust vector control system (2 pcs.); 4 - fairing; 5 - front nozzle block; 6 - solid propellant charge; 7 - docking frame; 8 - block of telemetry equipment; 9 - bandage rings; 10 - engines of the TTU separation system (4 blocks); heat shield.
(click to view scan)
Rice. 121. The mechanism of secondary injection. 1 - boundary layer; 2 - separation jump; 3 - separation flow boundary; 4 - injection hole; 5 - head shock; 6 - boundary of the injection zone.
hole, leads to the appearance of a lateral reactive force; secondly, an additional lateral force is created due to a change in the pressure distribution on the nozzle wall. The second effect increases the side component compared to the case when the liquid is injected not into but directly into the surrounding atmosphere. For example, when blowing into the nozzle, an increase in the lateral force by 2-3 times was observed. The effectiveness of such a thrust vector control system in the yaw and pitch planes for solid propellant rocket engines with a single central nozzle depends on the location of the inlet and the flow rate of the injected substance. The magnitude of the lateral component when blowing gas into the nozzle or injecting a nonevaporating liquid can be calculated in a different way (different from that described in Section 10.2), approximating the shape of the boundary surface between the injected substance and the main flow by a half-cylinder with a hemispherical base.
From the side of the main flow, a pressure force acts on this surface, parallel to the wall and proportional to where is the radius of the cylinder, the average static pressure in the flow core. Neglecting evaporation, mixing, and viscous forces on the boundary surface, we write the balance condition between the momentum flow of the injected fluid parallel to the wall and the pressure force:
where the flow rate (assumed to be equal to the asymptotic fluid flow rate parallel to the wall), the asymptotic
the rate of the injected substance. If we assume that it is achieved as a result of the isentropic expansion of the liquid from the stagnation pressure to the pressure, then this is a known parameter that depends only on the thermodynamic properties of the injected substance. Hence,
The force normal to the wall has three components: 1) the normal velocity at the exit of the inlet hole), 2) the difference between the pressure forces at the outlet of the hole with and without injection, and 3) the difference between the integral over the inner surface of the nozzle from the pressure on the wall with and without injection. At sufficiently small nozzle opening angles, the expression for the lateral force has the form
where awx is the half-angle of the opening of the outlet socket of the nozzle, a dimensionless coefficient depending on the geometrical characteristics of the nozzle, the location of the inlet, and the ratio of the specific heat capacities of the substance in the exhaust jet. The calculation according to this formula is in good agreement with the experimental data.
If thrust vector control in the roll plane is required, then two nozzles can be used or a pair of thin longitudinal dividing ribs can be installed in the outlet bell and liquid is injected through the corresponding holes. From fig. 122 it can be seen that the holes provide pitch control, holes for yaw, and joint injection or roll. In a wind tunnel with water as an injected liquid, a parametric study of the pressure distribution in such a nozzle and its change depending on the ratio of the secondary and main flow rates was carried out, and the optimal position of the inlets for secondary injection was determined. These results were then used in the development of a special device in which a small charge of monopropellant based on PCA was burned, and freon-113 was injected into the nozzle (Fig. 123). The engine was installed in two precision bearings, allowing it to make free (without friction) movement in the roll plane. The rotational moment was measured using two beams welded perpendicular to the transition sleeve fastened to the front bottom of the solid propellant rocket motor. The beams were rigidly embedded in the stand and subjected to bending when a torque was applied. Measuring bridge with strain gauges,
Rice. 122. Schematic diagram of the central nozzle of the solid propellant rocket engine, which provides control along three axes.
placed on the beams, gave a signal that varies in proportion to the moment.
The results presented in fig. 124 show that the location of the injected substance inlet holes has little effect on the torque, giving deviations of only 10-15% (this is not surprising, since the position of the holes was chosen on the basis of tests with a cold working fluid), and the decrease in specific impulse due to
Rice. 123. Scheme of bench installation.
Rice. 124. (see scan) Experimental data on the dependence of the injected flow rate on the ratio of torque to thrust (a) and specific impulse and additional axial component of thrust (b).
by installing longitudinal ribs in the nozzle, it is compensated by liquid injection, and with an increase in liquid flow, the specific impulse increases.
On the "slalom" rolls are identical, that is, they are also large, but there is no understeer at all! At the same speed where the “haphazard” version slid the front end with might and main, the Outlander Sport just turns and goes on. The contrast is especially striking on an arc with a decreasing radius, where the behavior of the car seemed completely unrealistic. If the regular version could hardly pass this exercise at a speed of 30 km / h, then the new modification, which has S-AWC, easily completed it at 40 km / h.
The car behaves much more confidently both on a circle (sliding starts later), and when “rearranging”, which can also be passed at a higher speed and, unlike the usual version, with almost no drift. In a word, the behavior of the Outlander Sport in extreme conditions cannot be called anything other than miraculous - the crossover seems to ignore the laws of physics. Let's see now if the difference will be noticeable when driving on public roads.
Almost an athlete
First, let's remember the feeling of driving a regular Outlander, without the Sport prefix in the name, that is, without the S-AWC. The crossover stands perfectly on a straight line, ignores bumps and ruts, but when entering corners quickly, the driver has a feeling of insecurity due to large rolls and a lack of reactive force on the steering wheel. But if you drive calmly, everything returns to normal. The ride is at a height, although the chassis can no longer cope with frankly broken asphalt. However, in the vicinity of St. Petersburg, where the test took place, the roads are so bad in places that it is just right to drive not by car, but by tank. Among the shortcomings, I note a clear deterioration in the smoothness of the ride on the back sofa compared to the front seats. In addition, passengers in the second row can hardly hear those sitting in front due to the strong tire noise.
It is worth saying that this car was produced in 2013. And in 2014, the crossover received very significant improvements. So I have the opportunity not only to find out how the Outlander Sport modification rides, but also to evaluate other innovations in practice. First of all, I note a more assembled suspension, which began to repeat the asphalt microprofile a little more. But the updated chassis is better able to withstand serious impacts and, under normal driving conditions, is more resistant to rolls. Since 2014, all Outlander modifications have received this suspension.
But a tighter steering wheel is the prerogative of the Outlander Sport version only. And the feeling of the car has become completely different: he seemed to tighten his muscles, and I no longer feel insecure when quickly passing corners. Moreover, sports notes appeared in the behavior of the crossover! I like this car much better.
In addition, the comfort for the rear passengers has been significantly improved, primarily acoustic. All modifications of the 2014 Outlander received additional sound insulation, and this is noticeable to the “naked ear” - now I am calmly talking to the driver, sitting on the back sofa. A stiffer suspension, surprisingly, was less shaking. Yes, yes, this happens when the chassis is properly configured.
As for the S-AWC, during normal driving, its work is not felt in any way. This was to be expected. The system does its job imperceptibly, for which it is an honor and praise. In a word, Mitsubishi Outlander is getting better every year. In 2015, the crossover will have a global update. So, we are waiting for a new meeting.
Specifications Mitsubishi Outlander Sport 3.0
