Ornithopter propulsion

Abstract

FIELD: aircraft.SUBSTANCE: propulsion systems of heavier-than-air aircraft that use flapping movements to create lift and thrust. The ornithopter propulsion system includes twin propellers, a swash plate, cardan shafts, a gearbox, and an engine. Each propeller contains blades that are made with an aerodynamic profile. The blades are designed with the ability to change the angle of attack by 10-90 degrees using a swash plate. The swash plate contains a rotating mechanism on which the blade mounting hub is mounted. The blade mount hub is connected to the cardan shafts, which are joined with the gearbox, which is attached to the engine. The axes of rotation of the propellers are located horizontally and co-directionally with the fuselage of the ornithopter. The propellers are attached to the ornithopter fuselage through brackets installed perpendicular to the fuselage and the propeller rotation axes.EFFECT: increased lifting force of the ornithopter and flight stabilization.6 cl, 2 dwg

Description

[0001] The invention relates to the field of aircraft, in particular to aviation technology, namely to propulsion systems of heavier-than-air aircraft that use flapping movements to create lift and thrust, and can be used in the design of ornithopters, unmanned aerial vehicles and other ornithopters.

[0002] A POWER PLANT FOR AN ORNITHOPTER is known from the prior art [US 2003226933 A1, publ. [11.12.2003], characterized in that the ornithopter includes a hub, at least one pair of wings, each wing of the pair is hingedly connected at one end to the hub and is located diametrically opposite, the hub is adapted for rotation, the power plant is connected to one end of each wing, and the reciprocating motion of one end of each wing produces rotation of the hub, leading to lift and thrust for flight, with the possibility of a second pair of wings moving in antiphase for balance, the wings are made flexible with an aerodynamic profile, with an adjustable angle of attack and twisting through pairs and booms, the power plant includes an engine driving a drive wheel with an eccentric and levers for reciprocating motion, with linear bearings on the shaft to direct the movement, which ensures high propulsive efficiency without torque,suitable even for muscular power, with the ability to change the ratio of vertical movement to rotation to adjust flight characteristics.

[0003] The disadvantage of this power plant for an ornithopter is that the dependence on the reciprocating motion of the wings without synchronous rotation leads to flight instability and a decrease in lift due to unbalanced vertical impulses, and the lack of mechanisms for dynamic orientation change leads to torque, worsening stabilization without additional counter-rotation devices.

[0004] Also known from the prior art is a SPIRAL PROPELLER OF AN ORNITHOPTER [CN 218559175 U, publ. 03.03.2023], characterized in that the helical propeller includes a central column and at least one blade, the root of the blade is mounted on the central column, the blade is made of a flexible and recoverable material, wherein in a first operating mode, such as takeoff / landing or hovering, the difference between the angle of the blade at the root and at the tip is a first twist angle, and in a second operating mode, such as cruising flight, this difference is a second twist angle, greater than the first, with a drive device for mutual conversion between these twist angles, mounted on the central column and connected to the blade by a transmission, where the drive device includes a hydraulic cylinder or an electric drive with a pusher connected to the tip of the blade through a hinge and a lever for changing the shape of the blade,and the blade may have an integrated skeleton made of elastic material to support deformation, with the possibility of multiple blades symmetrically arranged around a central column, and integration into an ornithopter with an engine connected to the central column through a gearbox to rotate the propeller, allowing the aerodynamic characteristics to be adapted to different flight modes to optimize efficiency and reduce noise.

[0005] The disadvantage of this ornithopter helical propeller is that the use of deformable blades with variable twist without synchronous rotation of paired elements leads to uneven load distribution and vibrations in transient modes, reducing the overall lift due to losses due to ineffective flapping, and the lack of mechanisms for balancing torques aggravates flight instability, causing roll or yaw without additional stabilizing systems.

[0006] The closest in technical essence is the FLAPPER WING MECHANISM WITH VARIABLE ANGLE OF ATTACK [CN 112429227 A, published 02.03.2021] https: / / www.ozon.ru / product / komplekt-adapterov-pod-nomernoy-znak-geely-monjaro-dvs-pered-zad-ubiraet-pisk-parktronikov-1089117099 / ?advert=-lYP0V1eaIHFklDxBbF mvP64tgGs-_h-9NzGsqhodNmng07Dq8bw0pQeO29PIHIneWDR6jIr3MirrJrsnIr0mKtt1BUrBS855ukNv2u 3YVdDQdwjrim3DZS1JeFOOnIYLrKDQhuceorHLfEu0CT7RAGhX6XzmGHMOTGMo5pRqnf-ysSDTyQTZNeopZnr TuiID5Lb_zoTt7sBCBotyuIBiEmOzz_-WfdHIzks2PwFkTusybIygmVZ3NFGkv-1f5wfScNGqvTjwfXGAqn2 T7WumU75N6Q-XEV8ghLVvEmDXIk76_iR6Mq1K6f9HkRaB6bxIPbyzExUgnEMpcn7Bt9UV74l_9B-3dM&avtc =1&avte=2&avts=1713791187&keywords=%D0%90%D0%B4%D0%B0%D0%BF%D1%82%D0%B5%D1%80+%D0%B4%D0%BB%D1%8F+%D0%9D%D0%BE%D0%BC%D0%B5%D1%80%D0%B0+Geely+Monjaro&reviewsVariantMode=2, characterized in that it includes a motor, a drive assembly with a drive disk, first and second links, where the motor spindle is fixedly connected to one side of the disk,a first link is fixed on the other side of the disk and pivotally connected to the second link, a connecting assembly with third and fourth links, where the third link is fixed to the fuselage, and its other end is pivotally connected through a universal joint to the fourth link fixed to the second link, and a rotor mechanism with a mounting axis perpendicular to the plane of the fourth link and the fuselage, fixed at the other end of the fourth link, and rotor blades rotating on the axis, with the possibility of the second link as an electric pusher with a power source for changing the length and angle of attack, a bearing on the axis for fixing the blades, a plurality of blades with the possibility of rotating clockwise and counterclockwise around their axis with a symmetrical profile, a motor as a servomotor or steering motor, and carbon fiber components to reduce weight, which simulates the flapping of wings with a constant lift throughout the cycle due to the rotation of the blades,increasing flight efficiency,

[0007] The main technical problem with the prototype is that the use of a linear flapping motion without paired rotating elements leads to asymmetric loads and vibrations in the cycle, reducing the overall lift due to losses due to ineffective oscillations, and the lack of mechanisms for collective angle control causes flight instability, provoking roll or yaw without additional balancing systems.

[0008] The objective of the invention is to eliminate the shortcomings of the prototype.

[0009] The technical result of the invention consists in increasing the lifting force of the ornithopter and stabilizing the flight of the ornithopter.

[0010] The technical result is achieved due to the fact that the ornithopter propulsion system, including twin propellers, a swash plate, cardan shafts, a gearbox, an engine,

[0011] each propeller contains blades that are made with an aerodynamic profile,

[0012] In addition, the blades are designed with the ability to change the angle of attack by 10-90 degrees using a swash plate,

[0013] The swashplate contains a rotating mechanism on which the blade mounting hub is mounted,

[0014] Also the blade mounting hub is connected to the cardan shafts, which are connected to the gearbox, which is connected to the engine,

[0015] The motor, together with the gearbox, is designed to ensure synchronous rotation of the screws,

[0016] in this case, the axes of rotation of the propellers are made horizontally directed and co-directed with the fuselage of the ornithopter,

[0017] The screws are secured to the ornithopter fuselage through brackets,

[0018] in this case, the brackets are installed perpendicular to the ornithopter fuselage and the axes of rotation of the propellers.

[0019] In particular, each propeller contains 2 to 10 blades.

[0020] In particular, the propeller blades are designed to rotate up to 300 rpm.

[0021] In particular, the propeller blades are made of composite materials.

[0022] In particular, the blades are made from 1.0 to 15 m long and from 0.2 to 0.5 m wide.

[0023] In particular, the propeller blades are made with rounded ends.

[0024] Brief description of drawings

[0025] Fig. 1 shows a general view of the ornithopter propulsion unit.

[0026] Fig. 2 shows a block diagram of the ornithopter propulsion system.

[0027] The figures indicate: 1 - propellers, 2 - ornithopter fuselage, 3 - blades, 4 - swash plate, 5 - cardan shafts, 6 - gearbox, 7 - engine, 8 - blade mounting hub, 9 - brackets, 10 - rotary mechanism.

[0028] Implementation of the invention

[0029] Ornithopter propulsion pertains to the field of aircraft, specifically to propulsion designs for ornithopters (ornithopters). Ornithopters (ornithopters) are a class of heavier-than-air aircraft that generate lift through the flapping motion of their aerodynamic surfaces and are maintained in flight primarily through the reaction of the air with its surfaces, which are imparted a flapping motion, simulating the flight of birds or insects.

[0030] Ornithopters (ornithopters) are a class of heavier-than-air aircraft that generate lift and are maintained in flight primarily through the reaction of the air with their aerodynamic surfaces (wings), which are given a reciprocating flapping motion in the vertical plane, simulating the principle of flight of birds or insects, in contrast to fixed-wing aircraft that use translational motion, or helicopters that use a rotor with a constant angle of attack of the blades during rotation.

[0031] Traditional ornithopters use paired wings that reciprocate up and down, providing aerodynamic lift during the downward phase of the flight. However, this design often faces efficiency issues, complex drive mechanisms, and limited maneuverability.

[0032] This ornithopter propulsion device offers an alternative approach by replacing the wings with paired propellers 1 with a horizontal axis of rotation, located symmetrically on the sides of the ornithopter fuselage 2, which makes it possible to optimize the generation of lift due to differentiated air resistance on the blades 3 of the propellers 2 in different phases of rotation, thereby increasing the lift of the ornithopter and stabilizing the flight of the ornithopter, which provides an efficiency ratio (the ratio of lift to power consumption) in the range of 0.8-0.9, a lift coefficient of up to 1.5-2.0, a reduction in energy consumption in the ascending phase of the movement of the blades 3 to a level corresponding to the angle of attack, and optimization of the maneuverability of the ornithopter by adapting the swash plate 4, which makes it possible to change the angles of attack of the blades 3 depending on the flight mode.

[0033] By paired propellers 1 are meant two or more coaxial propellers 1 with a horizontal axis of rotation, which are the main supporting element of the propulsion device of this ornithopter, which are located symmetrically on the sides of the fuselage of the ornithopter 2 and replace the traditional flapping wings, while each propeller is designed to create a lifting force due to a cyclic change in the angle of attack of its blades 3 depending on their azimuthal position during rotation, which simulates the working and idle stroke of the wing flapping.

[0034] By symmetrically located propellers 1 on the sides of the fuselage of the ornithopter 2 is meant such a design scheme in which two identical propellers 1 are mounted on the left and right sides of the fuselage of the ornithopter, located at an equal distance from its central longitudinal axis and having the same geometric and kinematic parameters, which ensures the balancing of the aerodynamic forces and moments created by them to eliminate the roll and yaw of the apparatus in horizontal flight and ensures the parallelism of their axes of rotation both to each other and to the longitudinal axis of the fuselage.

[0035] The lift force of an ornithopter is understood to be the aerodynamic vertical force created by the apparatus’s propulsion device and directed upward against the action of gravity, which in this device is generated not by classical flapping wings, but by paired rotating propellers 1 due to the asymmetric (differential) change in the angle of attack of their blades 3 at different phases of rotation, which provides a high lifting impulse with a lift coefficient from 1.5 to 2.0 and a high efficiency coefficient (the ratio of lift to power consumption) in the range of 0.8-0.9.

[0036] By stabilization of the flight of an ornithopter we mean a complex property and functional capability of an aircraft to maintain a given spatial position and flight trajectory, ensured in a given propulsion system by means of the symmetrical operation of the twin propellers 1 and the dynamic control of the angles of attack of their blades 3 through the swash plate 4, which allows for active compensation of external disturbances (wind gusts), countering the arising rolling and yaw moments due to the differential change in the lifting force on each propeller and maintaining a constant balance of aerodynamic forces to prevent uncontrolled oscillations, rotations or loss of altitude, also achieved by structural symmetry, synchronous rotation of the propellers 1 and the use of vibration dampers in the drive system to dampen vibrations, which together improves controllability, flight safety and reduces the load on the pilot.

[0037] Ornithopter propulsion unit, includes paired propellers 1, swash plate 4, cardan shafts 5, gearbox 6, engine 7.

[0038] By swashplate 4 we mean a control mechanism adapted from helicopter engineering, installed on each of the twin propellers 1 of the propulsion unit and designed to cyclically change the angle of attack of the blades 3 depending on their azimuthal position during rotation, which ensures an asymmetric operating mode of the blades 3, which simulates the flapping of a wing and allows dynamically adapting the flight to various modes, adjusting the lifting force and torque of the propellers 1 in order to increase maneuverability, stabilize the flight and optimize energy consumption, while structurally including dampers to dampen vibrations and ensures a smooth change in angles.

[0039] The cardan shafts 5 are understood to be the elements of the propulsion transmission, which are composite shafts that transmit torque from the gearbox 6 to the hubs of the blades 8 of each of the paired propellers 1, thereby providing compensation for possible misalignments between the units and allowing the engine 7 and gearbox 6 to be placed inside the fuselage 2 for optimal mass distribution, and also serve to partially absorb and dampen torsional vibrations and oscillations arising from cyclic changes in the load on the blades 3, thereby increasing the reliability and smoothness of the operation of the entire ornithopter power plant and maintaining the integrity of the structure under dynamic loads.

[0040] Unlike classic ornithopters, where the lift force is generated by the flapping movements of the wings, in this ornithopter propulsion system this function is assigned to the rotating propellers 1. Each propeller 1 contains a blade mounting hub 8, to which the blades 3 are attached. In this case, the rotation axes of the propellers 1 are made horizontally directed and co-directional with the fuselage of the ornithopter 2 and are located in the direction of movement of the aircraft (directed in the direction of movement - from front to back).

[0041] By horizontally directed axes of rotation of propellers 1 is meant such a spatial orientation in which the axes around which the hubs of the blades 8 with the blades 3 rotate are located parallel to the earth's surface (horizontally) and are directed along the longitudinal axis of the fuselage of the ornithopter 2 (from front to back in the direction of travel), which allows the blades 3 to perform a rotational movement primarily in vertical planes located on the sides of the aircraft, and thereby ensures the conversion of the rotational moment from the engine 7 into a cyclic, flapping movement of the blades, which is the main principle of generating lift in this propulsion device, replacing the traditional reciprocating wing movements.

[0042] By the axes of rotation of the propellers 1 co-directed with the fuselage of the ornithopter 2, we mean their orientation in space in which the direction vectors of these axes completely coincide with the direction vector of the longitudinal axis of the fuselage of the ornithopter 2, that is, the axes of rotation of the propellers 1 are oriented along the fuselage of the ornithopter 2 from its nose to the tail (from front to back in the direction of travel), which ensures the parallelism of the axes of the propellers 1 and the central axial line of the fuselage of the ornithopter 2, sets the correct plane of rotation of the blades 3 (vertical) for effective imitation of wing flapping, minimizes the aerodynamic drag of the structure in flight and contributes to the creation of a synchronous, balanced lift force on the sides of the apparatus.

[0043] Propellers 1 are attached to the ornithopter fuselage 2 via brackets 9 at a distance no less than the length of blade 3 to prevent airflow interference between them. The axis of rotation of each propeller 1 is aligned with the aircraft's flight direction, allowing blades 3 to perform cyclical movements in the vertical plane, analogous to wing flapping. Each propeller 1 contains from 2 to 10 blades 3.

[0044] Brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, thereby the axes of rotation of the propellers 1 and the central axial line of the fuselage 2 of the ornithopter are made parallel.

[0045] By perpendicular installation of brackets 9 to the fuselage of ornithopter 2 and the axes of rotation of propellers 1 is meant such a design installation scheme, in which the support brackets are fixed on the side surfaces of the fuselage of ornithopter 2 at a right angle (90°) to its longitudinal axis and simultaneously at a right angle to the axes of rotation of propellers 1 themselves, which ensures rigid and oriented extension of propellers 1 to the sides of the fuselage of ornithopter 2, guarantees parallelism of the axes of rotation of propellers 1 to the central axial line of the fuselage of ornithopter 2, creates the necessary safe gap between rotating blades 3 and the fuselage of ornithopter 2 to prevent their collision and effectively counteracts the torques arising during the operation of propulsion unit 7, thereby ensuring stability of fastening, minimization of vibrations and the correct geometry of air flows around blades 3 without interference with ornithopter 2 fuselage.

[0046] The central axial line of the fuselage of the ornithopter 2 is understood to be an imaginary longitudinal line passing through the geometric and force center of the structure of the fuselage of the ornithopter 2 from the nose to the tail, which is the basic axis of symmetry of the aircraft, determining its longitudinal orientation in space, and serves as a key design and aerodynamic reference for ensuring balancing, symmetrical arrangement of all elements of the propulsion system (in particular, the parallelism of the axes of rotation of the propellers 1), the correct distribution of masses and aerodynamic loads, as well as the correct operation of the control system, since it is relative to this line that the perpendicularity of the fastening of the brackets 9 and the co-direction of the axes of rotation of the propellers 1 are ensured, which together guarantees the stability and controllability of the ornithopter in flight.

[0047] The blades of 3 propellers 1 are designed to rotate at up to 300 rpm, which is selected depending on the weight of the aircraft and the required speed.

[0048] The 3 blades of propeller 1 are key structural elements and are made of composite materials such as carbon fiber or fiberglass, reinforced with metal inserts for strength. Each propeller 1 contains 3 blades, which are designed with an aerodynamic profile of variable thickness: at the junction of blade 3 with the hub of the 8 blade mount, a thicker section provides structural rigidity, and at the tip of blade 3, a thinner section reduces drag. Blades 3 are made from 1.0 to 15 m in length and from 0.2 to 0.5 m in width, with rounded tips to minimize vortex losses. In cross-section, the profile of blade 3 can be symmetrical or asymmetrical, which provides an optimal lift coefficient of up to 1.5-2.0 at angles of attack of 10-90 degrees. Blades 3 are designed with the ability to change the angle of attack by 10-90 degrees using a swash plate 4.

[0049] The operating mechanism of propeller 1 is based on differential changes in the angle of attack of blades 3 depending on their position in the rotation cycle. When blade 3 moves downward (the downward phase), its profile is oriented horizontally, maximizing the angle of attack of the air. This leads to significant air resistance, generating lift similar to a bird's downward wingbeat. During this phase, blade 3 experiences maximum force, creating upward thrust.

[0050] Conversely, during the upward movement (ascending phase), the blade 3 profile rotates vertically, minimizing the angle of attack to 0-5 degrees. This reduces air resistance and allows blades 3 to lift body 1 with minimal energy consumption. This asymmetry provides pure lift without significant friction losses, with an efficiency ratio (the ratio of lift to power consumption) of up to 0.8-0.9.

[0051] The aerodynamic profile of the blades 3 is understood to be the profiled shape of the cross-section of the blade 3, which, when interacting with the oncoming air flow, creates aerodynamic forces (lift and drag), while in this propeller the profile is made variable in thickness: at the root (in the area of ​​​​attachment to the hub of the blades 8) it is thicker to ensure structural strength and rigidity, and towards the end of the blade 3 it becomes thin to minimize induced drag and vortex formation, and the profile of the blade 3 itself can be both symmetrical and asymmetrical (convex-concave), which, in combination with the ability to change the angle of attack from 10 to 90 degrees through the swashplate 4, allows you to optimize the creation of lift in the descending phase (maximum angle, high drag) and minimize energy costs in the ascending phase (minimum angle), achieving a lift coefficient of up to 1.5-2.0.

[0052] The angle of attack of blades 3 is understood to be between the chord of the aerodynamic profile of blade 3 and the direction of the oncoming air flow, which in this propeller is a key controlled parameter, cyclically changed by the swash plate 4 depending on the azimuthal position of blade 3 during the rotation of propeller 1.

[0053] Differential change in the angle of attack of blades 3 means the operating mode of the propeller, in which the angle of attack of each blade 3 is not constant, but changes cyclically and asymmetrically depending on its azimuthal (circular) position during one revolution of the propeller 1, which is realized by means of the swash plate 4: when blade 3 is in the descending part of the trajectory (approximately from 0 to 180 degrees azimuth), it is given the maximum angle of attack (up to 90 degrees) to create powerful aerodynamic drag and lift, and when moving in the ascending part of the trajectory (from 180 to 360 degrees), the angle of attack of blade 3 automatically decreases to minimum values ​​​​(0-5 degrees), which sharply reduces the resistance and energy costs for lifting blade 3, thereby creating a significant positive difference (differential) in the lift between half-turns, which provides a high lifting impulse and an efficiency coefficient of 0.8-0.9,by simulating and optimizing the biomechanics of a bird's wing flapping,

[0054] Swashplate 4 is installed on each rotor 1 and comprises a rotating mechanism 10, on which a blade mounting hub 8 is mounted, enabling control of the angle of attack of the blades 3, adapted from helicopter designs. Rotating mechanisms 10 are part of the blades 3, securing the blades 3 to the blade mounting hub 8 and ensuring their rotation around the longitudinal axis depending on the azimuth position, with the integration of dampers to prevent vibration.

[0055] The operating principle of swashplate 7 is similar to that of a helicopter: it periodically adjusts the pitch angle of blade 3 depending on its azimuth position. When blade 3 passes the bottom of its trajectory, swashplate 4 rotates blade 3 around its axis to achieve a minimum angle of attack. At the top of its trajectory, it maximizes the angle of attack of blade 3, achieved by rotating its plane with swashplate 4.

[0056] Swashplate 4 allows the angle of attack of blades 3 to be adjusted by 10-90 degrees, depending on the flight mode. Rotating mechanism 10 of swashplate 4 ensures smooth operation. Swashplate 4 also contains vibration dampers that prevent resonant vibrations.

[0057] The fuselage of ornithopter 2 serves as the base for mounting propellers 1 and brackets 9. It is made of lightweight materials such as aluminum alloys or composites, with a length of 3-6 meters and a width of 1-2 meters to ensure aerodynamic streamlining. Propellers 1 are attached to the fuselage of ornithopter 2 through brackets 9, and are fixed through bearing units on the side consoles of the fuselage of ornithopter 2, located at a height of 1-1.5 meters from the ground to prevent blades 3 from contacting the surface. The connection is achieved by bolted fasteners with shock absorbers to absorb vibrations. The internal structure of the fuselage of ornithopter 2 includes a frame made of profiles, which increases rigidity and distributes the loads from propellers 1.

[0058] The propeller drive system 1 includes an engine 7 with a power of up to 200 kW, connected to a gearbox 6 to ensure optimal speed. Gearbox 6 is made of a planetary or toothed type, with a gear ratio of 5-10:1 and is mounted inside the fuselage of the ornithopter 2 and transmits torque to the cardan shafts 5. The blade mounting hub 8 is connected to the cardan shafts 5, which are connected to gearbox 6, which is connected to engine 7. Engine 7 is designed with a torque of up to 500 Nm, a rotation speed of 2000-3000 rpm. Engine 7, together with gearbox 6, is designed to ensure synchronous rotation of propellers 1, which is ensured by a control system that prevents imbalance and provides symmetrical lift.

[0059] Synchronous rotation of propellers 1 means a coordinated mode of operation of paired propellers, in which both propellers 1, located on the sides of the fuselage of the ornithopter 2, rotate with the same angular velocity (number of revolutions per minute) and in identical phases due to a single drive from the engine 7 through the gearbox 6 and the cardan shafts 5, which ensures the symmetry of the aerodynamic forces and moments generated by them at each moment in time, thereby preventing the occurrence of unbalancing rolling, yaw or turning moments that could lead to an unstable or uncontrolled flight of the aircraft, and guarantees a uniform distribution of the load on the structure, maximum efficiency in creating lift, optimal energy consumption and the overall stability of the ornithopter due to the simultaneous and identical passage of the blades 3 of both propellers 1 of the same phases of the cycle.

[0060] The ornithopter propulsion system includes twin propellers 1, a swash plate 4, cardan shafts 5, a gearbox 6, and an engine 7, which increases the lifting force of the ornithopter and stabilizes the flight of the ornithopter by creating a highly efficient asymmetric lift generation system, where twin propellers 1 with a horizontal axis of rotation, replacing traditional flapping wings, provide the main thrust, and the swash plate 4 implements the key principle of differential change in the angle of attack of the blades 3, maximizing useful air resistance during the power stroke and minimizing energy consumption during idle, which directly leads to achieving a high lift coefficient and efficiency coefficient, while stabilization is achieved due to the synchronous operation of the entire system: engine 7, through gearbox 6, sets the same and optimal speed for propellers 1, cardan shafts 5 reliably transmit torque, compensating for misalignment and dampening vibrations,and the swash plate 4 allows not only to generate lift, but also to actively control it, instantly adapting the angles of attack of the blades 3 to counter external disturbances and compensate for possible imbalance, thereby ensuring the symmetry of the generated forces, a stable spatial position of the apparatus and its controllability in all flight modes.

[0061] Each propeller 1 contains blades 3, which are made with an aerodynamic profile, which increases the lifting force of the ornithopter and stabilization of the flight of the ornithopter by optimizing the interaction of the blades with the air flow in all phases of rotation: a calculated profile (symmetrical or asymmetrical) with a variable thickness increased at the root for strength and reduced at the end to reduce induced drag, which ensures high aerodynamic quality and allows, with a variable angle of attack of the blade 3 from 10 to 90 degrees, to achieve the maximum lift coefficient in the working descending phase, effectively converting air resistance into vertical thrust, and also minimizes losses and vortex formation in the ascending phase due to the ability to set the minimum angle of attack, which, together with the rounded ends of the blades 3, increases the overall efficiency coefficient of the propeller, while flight stabilization is ensured due to the fact thatthat the predictable and controlled behavior of the profiled blades 3 in the flow, controlled by the swash plate 4, allows for the creation of a uniform, synchronous and balanced lift force on the propellers 1, reduces the level of turbulence and unwanted vibrations, and their rigid design guarantees the maintenance of the specified geometric and kinematic parameters throughout the flight, preventing flutter and ensuring a stable trajectory of the apparatus.

[0062] Blades 3 are designed with the ability to change the angle of attack by 10-90 degrees using the swash plate 4, which increases the lifting force of the ornithopter and stabilization of the flight of the ornithopter due to the implementation of the principle of a radically asymmetric working cycle, in which in the descending phase of rotation of the blade, the maximum angle of attack is set, which turns it into an effective aerodynamic brake that creates powerful resistance and, as a result, high vertical thrust, similar to a strong flapping of a bird's wing, and in the ascending phase, the angle of attack decreases to minimum values, which sharply reduces drag and allows blade 3 to rise with minimal energy consumption, creating a pure positive impulse of lift with a high efficiency coefficient, while flight stabilization is ensured due to the fact that the swash plate 4, performing such a cyclic and precisely dosed change in angles, allows not only to generate lift,but also actively control its distribution: it can dynamically compensate for the resulting heeling moments by differentially adjusting the angles of attack of the blades 3 on the propellers 1, counteract wind gusts by quickly adapting the profile of the blades 3 to the changing flow, and also maintain the synchronicity of the operation of the propellers 1, preventing turns and yaws of the apparatus, which, together with vibration damping, ensures a stable, balanced and controllable position of the ornithopter in the air.

[0063] When the angle of attack of blade 3 changes to an angle of less than 10 degrees, it reduces the lift of the ornithopter and the stabilization of the flight of the ornithopter due to the fact that blade 3 loses the ability to create significant aerodynamic drag and, accordingly, sufficient vertical thrust in the descending phase of its rotation, since at such small angles of attack, the aerodynamic profile of blade 3 is practically not slowed down by the air flow, which leads to a sharp decrease or complete disappearance of the useful difference (differential) in the lift force between the working (descending) and idle (ascending) half-turns, as a result of which the overall lift coefficient drops, and the efficiency coefficient (the ratio of lift to power) decreases due to non-optimal conversion of engine energy, while flight stabilization worsens, since the main working cycle of the propulsion unit is disrupted: the necessary asymmetry of forces disappears,which deprives the system of the ability to generate a stable and predictable lift impulse, and also sharply reduces the efficiency of control through the swash plate 4 - the apparatus loses the ability to quickly compensate for heeling moments and external disturbances (gusts of wind) due to a differential change in angles, which leads to an increase in parasitic oscillations, loss of balance, an increased tendency to rocking and a significant complication of piloting, since the propulsion system ceases to perform its main function of creating a balanced and controlled lift force.

[0064] When the angle of attack of blade 3 changes to an angle of more than 90 degrees, it reduces the lifting force of the ornithopter and the stabilization of the flight of the ornithopter by disrupting the optimal aerodynamic operating mode of the profile, in which blade 3, instead of creating an effective drag converted into vertical thrust, goes into a deep flow stall mode with the formation of extensive turbulent zones, which sharply increases the drag without a corresponding increase in useful lift, and in extreme cases can even change its direction, negating the differential operating principle of the propeller and causing a drop in the overall lift coefficient and a decrease in the efficiency coefficient (the ratio of lift to power) due to unproductive energy consumption, while flight stabilization is deteriorating, since an excessive angle of attack leads to the occurrence of unpredictable and sharply changing aerodynamic loads on blade 3 and the entire structure, which causes strong vibrations,the risk of flutter and loss of control of the swash plate 4, which cannot effectively compensate for heeling moments and external disturbances in such an off-design mode, the synchronicity and balance of forces between the twin propellers 1 is disrupted, which leads to instability of the apparatus, its rocking and difficulties in maintaining a given flight path.

[0065] The swashplate 4 comprises a rotating mechanism 10 on which the blade mounting hub 8 is mounted, which increases the lifting force of the ornithopter and the flight stabilization of the ornithopter by providing direct, precise and synchronized control of the angle of attack of each blade 3 directly during the rotation of the propeller 1, since the rotating mechanism 10, integrated into the blade mounting hub 8, allows the control actions to be transmitted from the swashplate 4 directly to the blades 3, ensuring their rotation around the longitudinal axis in accordance with the azimuthal position, which implements the key principle of differential change in the angle of attack (from 10 to 90 degrees) - the maximum angle in the descending phase to generate peak lift and the minimum in the ascending phase to save energy, thereby directly optimizing the lift coefficient and efficiency, while flight stabilization is achieved due to the fact thatthat the entire kinematic chain (swashplate 4 - rotary mechanism 10 - blade mounting hub 8) ensures not only the generation, but also the active, instantaneous redistribution of aerodynamic forces: the system allows for the compensation of imbalance and external disturbances through differential adjustment of the angles on propellers 1, and the rigid and precise connection of the elements through rotary mechanism 10 and blade mounting hub 8 guarantees synchronicity and predictability of the reaction of blades 3, minimizes phase shifts and parasitic oscillations, and integrated dampers effectively dampen vibrations, which together ensures a stable, balanced and controllable position of the apparatus in space.

[0066] The blade mounting hub 8 is connected to the cardan shafts 5, which are connected to the gearbox 6, which is connected to the engine 7, which increases the lifting force of the ornithopter and the stabilization of the ornithopter's flight by creating a reliable, balanced and efficient power transmission that ensures strictly synchronous rotation of the propellers 1 at the speed optimal for generating lift (up to 300 rpm), converting the high speed and torque of the engine 7 (up to 500 Nm) through the gearbox 6 with a gear ratio of 5-10: 1 into the required force on the blade mounting hubs 8, which guarantees stable and powerful operation of the blades 3 in the calculated modes to achieve a high lift coefficient, while flight stabilization is achieved due to the fact that this kinematic chain ensures symmetry of rotation of the paired propellers 1, preventing the occurrence of turning and heeling moments, and the cardan shafts 5, compensating for possible misalignments and damping torsional vibrations,eliminate the transmission of harmful vibrations to the structure and maintain the integrity and precision of the entire system under dynamically changing loads on the blades 3, which, in combination with control from the swash plate 4, ensures smooth, stable and controlled flight of the apparatus.

[0067] The engine 7, together with the gearbox 6, is designed to provide synchronous rotation of the propellers 1, which increases the lifting force of the ornithopter and stabilization of the flight of the ornithopter by forming a strictly balanced and constant force action over time on both propellers, in which the gearbox 6 with a gear ratio of 5-10: 1 converts the high-speed rotation of the shaft of the engine 7 with a power of up to 200 kW into optimal operating speeds of the propellers 1 (up to 300 rpm), guaranteeing identical angular velocity and phase coincidence of their rotation, which eliminates the occurrence of differential aerodynamic forces between the left and right sides of the apparatus and, as a result, prevents the occurrence of parasitic heeling, yaw or turning moments that can upset the balance, which directly increases the resulting lifting force, since the paired propellers 1 simultaneously and in one phase pass the working section of the cycle (the descending phase with maximum angle of attack),creating a powerful synchronous thrust impulse, which optimizes the overall lift coefficient, while flight stabilization is achieved due to the fact that synchronicity, maintained by a single mechanical connection through gearbox 6, ensures predictable and symmetrical operation of the propeller in any mode, allows the control system through the swash plate 4 to accurately and equally influence the propellers 1 to compensate for external disturbances, and also fundamentally eliminates the main source of dynamic instability - thrust asymmetry, which together ensures smooth, stable and controlled flight without involuntary oscillations and rotations.

[0068] The rotation axes of the propellers 1 are made horizontally directed and co-directional with the fuselage of the ornithopter 2, which increases the lifting force of the ornithopter and stabilization of the flight of the ornithopter due to the optimal organization of the working cycle of the blades 3 and the aerodynamic balancing of the entire apparatus: the horizontal orientation of the axes ensures the rotation of the blades strictly in vertical planes on the sides of the fuselage of the ornithopter 2, which makes it possible to most effectively implement the principle of differential change in the angle of attack - the blade 3 in the descending phase moves perpendicular to the oncoming flow, creating maximum resistance and lift, and in the ascending phase, it slides with minimal resistance, which ensures a high lifting impulse and a high efficiency coefficient, the co-direction of the rotation axes of the longitudinal axis of the fuselage of the ornithopter 2 (from front to back) guarantees the parallelism of the planes of rotation of the propellers 1,the symmetry of the aerodynamic forces they create relative to the center of mass of the apparatus and the minimal frontal drag of the structure in flight, which is important for stabilization - such geometry eliminates the occurrence of parasitic lateral forces and turning moments, allows the control system through the swash plate 4 to predictably and synchronously control the angles of attack on the propellers 1 to compensate for roll and external disturbances, and also ensures uniform air flow around the apparatus, preventing rocking and maintaining the overall stability of the trajectory.

[0069] Propellers 1 are secured to the fuselage of the ornithopter 2 through brackets 9, which increases the lifting force of the ornithopter and stabilization of the flight of the ornithopter by providing the necessary structural extension of the rotating propellers to a safe distance from the body (not less than the length of the blade 3), which completely prevents interference of air flows between the blades 3 and the fuselage of the ornithopter 2, thereby allowing each propeller 1 to operate in a clean, undisturbed flow and develop maximum aerodynamic lift in the descending phase without losses due to turbulence, while flight stabilization is achieved due to rigid fastening through brackets 9 installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, which ensures parallelism of the axes of the propellers 1 to the longitudinal axis of the apparatus, symmetry of their location relative to the center of mass and, as a consequence, balancing of the created lifting and aerodynamic moments,eliminating the occurrence of uncontrolled rolls and yaws, and also reliably transfers all dynamic loads from the propellers 1 to the fuselage power frame, absorbing vibrations through shock absorbers in the attachment points, which together ensures stable and predictable behavior of the ornithopter in flight.

[0070] Brackets 9 are mounted perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, which increases the lifting force of the ornithopter and stabilization of the flight of the ornithopter by ensuring an invariable geometry of the entire power structure of the propulsion unit, which ensures that the planes of rotation of the propellers 1 remain strictly vertical and parallel to each other, and their axes are co-directed with the longitudinal axis of the fuselage of the ornithopter 2, which is a fundamental condition for the symmetrical and most efficient operation of the blades 3 in the air flow without mutual interference, allowing each blade 3 in the descending phase to create the calculated maximum drag and, consequently, the peak lift, while flight stabilization is achieved due to the fact that such a perpendicular and rigid fastening creates a kinematically correct and statically determinate system that reliably fixes the position of the propellers 1 relative to the center of mass of the apparatus,evenly distributes and transmits significant aerodynamic and inertial loads from their operation to the power frame of the ornithopter 2 fuselage, preventing unwanted bending and torsional deformations, and also eliminates the occurrence of parasitic moments that can cause roll or yaw, which, together with shock absorption in the attachment points, ensures vibration damping, high stability and predictable controllability of the ornithopter in all flight modes.

[0071] Each propeller 1 contains from 2 to 10 blades, which increases the lifting force of the ornithopter and the stabilization of the flight of the ornithopter by optimizing the frequency and uniformity of the generation of lifting impulses during one revolution of the propeller 1, since a larger number of blades 3 increases the frequency of working acts per unit of time, providing a smoother and more continuous nature of the lifting force with less pulsation, which directly increases its integral value and helps to achieve a high lift coefficient, and also allows for more efficient distribution of the aerodynamic load on the hub and drive, while flight stabilization is achieved due to the fact that the choice of the number of blades 3 in the specified range allows you to find the optimal compromise between the inertia, mass of the propeller 1 and the smoothness of its operation, which together contributes to the synchronous and balanced operation of the propellers 1,suppression of resonant vibrations and maintaining a stable spatial position of the apparatus,

[0072] Blades 3 of propellers 1 are configured to rotate at up to 300 rpm, which increases the ornithopter's lifting force and stabilization of its flight by ensuring an optimal frequency of operating cycles at which each propeller 1 generates a sufficient number of powerful lifting impulses (descending phases with a maximum angle of attack) per unit of time to create and maintain a high integral lifting force necessary for the separation and flight of an apparatus of a given mass, while limiting the maximum speed to 300 rpm prevents off-design modes from occurring, when flow stall, excessive growth of aerodynamic drag and inertial loads leading to a drop in the efficiency coefficient (the ratio of lift to power) may occur, while flight stabilization is achieved due to the fact that a given speed range allows for precise synchronization of the rotation of paired propellers 1 through gearbox 6, eliminating imbalance and beating,and also ensures the coordinated and predictable operation of the swash plate 4, which manages to change the angle of attack of the blades 3 in each phase of rotation, which guarantees a smooth and symmetrical creation of lift on both sides of the apparatus, suppresses the occurrence of resonant vibrations and parasitic oscillations of the structure, and allows the system to quickly compensate for external disturbances, maintaining the overall stability and controllability of the ornithopter.

[0073] The blades 3 of the propellers 1 are made of composite materials, which increases the lifting force of the ornithopter and the stabilization of the flight of the ornithopter due to the combination of low weight and high specific strength of materials such as carbon fiber or fiberglass, which helps to minimize the inertial loads and the moment of inertia of the blades 3 during their cyclic rotation and a sharp change in the angle of attack, thereby significantly reducing the required drive power to overcome their own weight and accelerate the blades 3 in the ascending phase, which releases energy to create useful lift in the descending phase and helps to achieve a high efficiency coefficient, while flight stabilization is ensured due to the fact that composite structures have high damping and controlled rigidity, which helps to dampen aerodynamic and mechanical vibrations, prevent flutter and resonance phenomena,and also to precisely maintain the specified complex geometry of the aerodynamic profile with variable thickness under all operating loads, ensuring predictable and stable behavior of each blade in the flow, which, together with the ability to manufacture long blades without loss of strength, guarantees uniform, synchronous and balanced creation of lift by both propellers, eliminating sources of dynamic instability.

[0074] Blades 3 are made with a length from 1.0 to 15 m, and a width from 0.2 to 0.5 m, which increases the lifting force of the ornithopter and the stabilization of the flight of the ornithopter by providing an optimal ratio of geometric parameters that directly determine the effective swept area and aerodynamic characteristics of the blades 3: a large length allows to significantly increase the area of ​​interaction with the air environment, which, while maintaining a given rotation frequency and angles of attack, leads to a proportional increase in the generated lift, and the choice of width (chord) in the range of 0.2-0.5 m provides the necessary profile rigidity and a balance between lift and drag, helping to achieve a high lift coefficient, while flight stabilization is achieved due to the fact that these dimensions, in combination with a variable profile and the use of composite materials, make it possible to create blades 3 with optimal mass and distributed rigidity,which minimizes inertial loads and bending deformations during cyclic changes in the angle of attack, prevents the occurrence of flutter and resonant oscillations, and also ensures uniform and symmetrical generation of lift force along the span of blade 3, which, together with rounded tips to reduce vortex formation, contributes to smooth and predictable operation of the propeller, a stable position of the apparatus in the air and effective flight control through the swash plate.

[0075] The blades 3 of the propellers 1 are made with rounded tips, which increases the lifting force of the ornithopter and the stabilization of the flight of the ornithopter by minimizing the induced drag and the intensity of the tip vortices that inevitably arise when the air flow passes around the blades 3, especially under conditions of cyclic changes in the angle of attack: the rounded shape of the tip of the blade 3 smoothly reduces the pressure difference between the upper and lower surfaces of the profile in the end part, which weakens the air turbulence and, as a result, reduces energy losses due to induced drag, allowing more power of the engine 7 to be converted into useful lift and contributing to the achievement of a high efficiency coefficient, while flight stabilization is ensured due to the fact that weakened tip vortices create fewer turbulent disturbances in the surrounding flow, which reduces the level of vibrations transmitted to the structure of the propellers 1 and the fuselage of the ornithopter 2,prevents the occurrence of resonant vibrations and ensures smoother and more predictable aerodynamic behavior of the blades 3 in all phases of rotation, which, together with the symmetrical operation of both propellers 1, promotes uniform distribution of aerodynamic loads, eliminates sudden changes in torque and maintains the overall stability and controllability of the apparatus in flight.

[0076] The technical result is achieved due to the fact that the ornithopter propulsion device includes paired propellers 1, a swash plate 4, cardan shafts 5, a gearbox 6, an engine 7, wherein each propeller 1 contains blades 3 that are made with an aerodynamic profile, in addition, the blades 3 are made with the ability to change the angle of attack using the swash plate 4 by 10-90 degrees, the swash plate 4 contains a rotary mechanism 10 on which the blade fastening hub 8 is mounted, also the blade fastening hub 8 is connected to the cardan shafts 5, which are connected to the gearbox 6, which is connected to the engine 7, the engine 7 together with the gearbox 6 is made with the ability to provide synchronous rotation of the propellers 1, wherein the axes of rotation of the propellers 1 are made horizontally directed and co-directed to the fuselage of the ornithopter 2, the propellers 1 are fixed to the fuselage of the ornithopter 2 through brackets 9, wherein the brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1,which increases the lifting force of the ornithopter and the stabilization of the ornithopter flight by creating an integral highly efficient system in which paired propellers 1 with horizontal co-directional axes, rigidly fixed through perpendicular brackets 9, provide the correct geometry for the rotation of the blades 3 in vertical planes, and the synchronous drive from the engine 7 through the gearbox 6 and cardan shafts 5 guarantees the absolute symmetry of their operation, excluding imbalance, the key element is the swash plate 4 with a rotating mechanism 10 on the blade mounting hub 8, which implements a differential change in the angle of attack of the aerodynamic profile of the blades 3 in the range of 10-90 degrees - the maximum angle in the descending phase creates peak drag and lift, the minimum in the ascending phase sharply reduces energy costs, which together provides a high net lifting impulse with a lift coefficient of 1.5-2.0 and an efficiency coefficient of 0.8-0.9,In this case, stabilization is achieved thanks to the complex interaction of all components: synchronous rotation and identical mounting geometry of propellers 1 eliminate parasitic moments, swash plate 4 allows instantaneous redistribution of angles of attack to compensate for external disturbances and rolls, and a rigid kinematic connection from engine 7 to blades 3 through damping cardan shafts 5 suppresses vibrations, thereby ensuring a stable, balanced and controllable position of the apparatus in flight.

[0077] The ornithopter propulsion system is used as follows.

[0078] The ornithopter propulsion system is used to generate lift and stabilize the aircraft's flight, simulating the principle of bird flight through the use of rotating propellers 1. First, engine 7 and gearbox 6 are installed within the fuselage of ornithopter 2, securing them to the power frame for optimal mass distribution and balance. Gearbox 6 is then connected to cardan shafts 5, which transmit torque from engine 7, compensating for possible misalignment and damping vibrations. Brackets 9 are then mounted perpendicular to the fuselage of ornithopter 2 and the axes of rotation of propellers 1, ensuring that propellers 1 are rigidly extended to the sides at a distance no less than the length of the blades 3 to prevent airflow interference. Screws 1 with horizontally directed rotation axes, co-directed with the longitudinal axis of the ornithopter fuselage 2, are attached to brackets 9 so that blades 3 rotate in vertical planes on the sides of the apparatus.

[0079] Next, each propeller 1 is assembled by installing 2 to 10 blades 3 made of composite materials with an aerodynamic profile of variable thickness, 1.0 to 15 m in length and 0.2 to 0.5 m in width, with rounded tips to minimize vortex losses, on the blade mounting hub 8. The blade mounting hub 8 is connected to the cardan shafts 5, and a swash plate 4 is mounted on each propeller 1, which contains a rotary mechanism 10 for cyclically changing the angle of attack of the blades 3 by 10-90 degrees depending on the azimuth position. Dampers are installed in the swash plate 4 and the rotary mechanism 10 to dampen vibrations and ensure smooth movement. After assembly, the synchronicity of rotation of screws 1 is checked by adjusting gearbox 6 with a gear ratio of 5-10:1 so that engine 7 provides the same angular speed of up to 300 rpm for both screws 1.

[0080] Prepare the ornithopter propulsion system for flight. First, turn on engine 7 to warm it up and check the operation of gearbox 6, cardan shafts 5, and propellers 1 at idle, ensuring there are no vibrations or imbalances. Next, calibrate swashplate 4, adjusting rotary mechanism 10 to precisely change the angle of attack of blades 3 so that the angle is up to 90 degrees in the descending phase for maximum lift, and up to 10 degrees in the ascending phase to minimize drag. Check the fastening of propellers 1 on brackets 9 and the parallelism of their axes to the fuselage of ornithopter 2. Balance the apparatus, distributing loads to prevent roll. Finally, conduct a test launch on the ground, rotating blades 3 at low speeds to confirm lift.

[0081] During flight, the ornithopter's propulsion system is controlled by regulating the power of engine 7 through the control system to maintain synchronous rotation of propellers 1 at an optimal speed of up to 300 rpm, depending on the speed and weight of the aircraft. Swashplate 4 is adapted to dynamically change the angle of attack of blades 3, compensating for external disturbances, such as gusts of wind, by differentially adjusting the angles of the left and right propellers 1 to counteract pitching and yaw moments. The operation of cardan shafts 5 and gearbox 6 is monitored to ensure smooth, loss-free torque transfer, and dampers in the rotary mechanism 10 are used to dampen vibrations. If maneuvering is necessary, the swashplate 4 modes are adjusted, increasing or decreasing the lift on individual blades 3, which optimizes the flight path and stabilizes the aircraft in the air.

[0082] Examples of ornithopter propulsion implementation

[0083] The first example of the implementation of an ornithopter propulsion system is a design for a small-sized unmanned aerial vehicle weighing up to 50 kg, intended for environmental monitoring. The propulsion system includes paired propellers 1, a swashplate 4, cardan shafts 5, a gearbox 6, an engine 7, wherein each propeller 1 contains blades 3, which are made with an aerodynamic profile of variable thickness, thicker at the root for rigidity and thin at the tip to reduce drag, with a symmetrical or asymmetrical cross-section for an optimal lift coefficient, in addition, the blades 3 are configured to change the angle of attack by 10-90 degrees using the swashplate 4, providing a differential change depending on the azimuthal position to maximize the lift in the descending phase and minimize energy costs in the ascending phase;the swashplate 4 comprises a rotary mechanism 10 on which a blade fastening hub 8 is mounted, with the integration of dampers for damping vibrations and smoothly changing angles, the blade fastening hub 8 is also connected to cardan shafts 5, which are connected to a gearbox 6, which is connected to an engine 7, where the cardan shafts 5 compensate for misalignments and dampen torsional vibrations, the engine 7, together with the gearbox 6, is configured to provide synchronous rotation of the propellers 1 through a planetary gearbox with a gear ratio of 5:1, guaranteeing identical angular velocity and phase coincidence for balancing forces; wherein the axes of rotation of the propellers 1 are made horizontally directed and co-directed with the fuselage of the ornithopter 2, oriented along the longitudinal axis from the nose to the tail for vertical rotation of the blades in planes on the sides;the propellers 1 are secured to the fuselage of the ornithopter 2 through brackets 9 at a distance of no less than the length of the blade 3 to prevent interference of flows; wherein the brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, ensuring parallelism of the axes and rigid extension of the propellers 1 to the sides with shock absorbers to absorb vibrations, wherein each propeller 1 contains two blades 3, which optimizes for low speeds and simplicity of design, reducing inertia and ensuring uniform impulses of lifting force, the blades 3 of the propellers 1 are designed with the ability to rotate up to 300 rpm, selected depending on the mass to achieve the optimal frequency of cycles without flow stall.

[0084] The second example of the implementation of an ornithopter propulsion system is a variant for a medium-sized apparatus weighing 200-500 kg, used in search and rescue operations with increased maneuverability. The propeller includes paired propellers 1, a swash plate 4, cardan shafts 5, a gearbox 6, an engine 7, wherein each propeller 1 contains blades 3 that are made with an aerodynamic profile, variable in thickness for structural strength at the root and minimization of vortices at the end, with an asymmetric section for angles of attack of 10-90 degrees, in addition, the blades 3 are made with the ability to change the angle of attack by means of the swash plate 4 by 10-90 degrees, implementing an asymmetric cycle with a maximum angle in the lower phase to generate thrust and a minimum in the upper phase to reduce drag, the swash plate 4 contains a rotating mechanism 10, on which a blade fastening hub 8 is mounted, with rotation of the blades 3 around the longitudinal axis and dampers to prevent resonance,also the hub of the blade fastening 8 is connected to the cardan shafts 5, which are connected to the gearbox 6, which is connected to the engine 7, where the cardan shafts 5 absorb vibrations and transmit torque without losses, the engine 7 together with the gearbox 6 is configured to provide synchronous rotation of the propellers 1 with a gear reducer 6 of a gear ratio of 7:1, maintaining phase synchronization to eliminate rolls, while the axes of rotation of the propellers 1 are made horizontally directed and co-directed to the fuselage of the ornithopter 2, parallel to the central axis for symmetrical flow and minimization of resistance, the propellers 1 are secured to the fuselage of the ornithopter 2 through brackets 9 with bearing assemblies at a height of 1-1.5 m from the ground, while the brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, ensuring a balance of loads and preventing deformations, each propeller 1 contains four blades 3,Increasing the pulse frequency for smoother lift and better stability, the 3 propeller blades 1 are made of composite materials such as carbon fiber with metal inserts for low weight, high strength and vibration damping, improving flight efficiency and stability.

[0085] The third example of the implementation of an ornithopter propulsion system is a configuration for a large cargo vehicle weighing over 1000 kg, intended for transportation in hard-to-reach areas. The propulsion device includes paired propellers 1, a swash plate 4, cardan shafts 5, a gearbox 6, an engine 7, wherein each propeller 1 contains blades 3, which are made with an aerodynamic profile, with variable thickness and rounded ends to reduce vortex losses, in addition, the blades 3 are made with the ability to change the angle of attack using the swash plate 4 by 10-90 degrees, with a cyclic change to simulate the wing flapping and adapt to flight modes, the swash plate 4 contains a rotating mechanism 10, on which the blade mounting hub 8 is mounted, ensuring precise rotation and integration with the control system, also the blade mounting hub 8 is connected to the cardan shafts 5, which are connected to the gearbox 6, which is connected to the engine 7,with compensation of misalignments for reliable transmission of torque, the engine 7 together with the gearbox 6 is designed with the ability to provide synchronous rotation of the propellers 1 through a planetary mechanism (gearbox 6) with a gear ratio of 10:1, preventing imbalance, while the axes of rotation of the propellers 1 are made horizontally directed and co-directed with the fuselage of the ornithopter 2, for vertical planes of rotation and balance of moments, the propellers 1 are secured to the fuselage of the ornithopter 2 through brackets 9 with bolt fasteners and shock absorbers, while the brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, distributing loads on the fuselage frame, each propeller 1 contains six blades 3, optimizing for high lifting capacity with uniform load distribution, the blades 3 are made 15 m long and from 0.2 to 0.5 m, providing a large area of ​​interaction with the air and a balance between force and resistance.

[0086] The fourth example of ornithopter propulsion implementation is a system for an experimental prototype with an emphasis on energy efficiency, weighing 100 kg for scientific research. The propeller includes paired propellers 1, a swash plate 4, cardan shafts 5, a gearbox 6, an engine 7, wherein each propeller 1 contains blades 3, which are made with an aerodynamic profile, asymmetrical for an optimal efficiency coefficient, in addition, the blades 3 are made with the ability to change the angle of attack with the help of the swash plate 4 by 10-90 degrees, with dynamic adaptation for stabilization and maneuverability, the swash plate 4 contains a rotary mechanism 10, on which a blade fastening hub 8 is mounted, with dampers for smoothness and vibration damping, also the blade fastening hub 8 is connected to cardan shafts 5, which are connected to the gearbox 6, which is connected to the engine 7, ensuring the transmission of torque with minimal losses;the engine 7 together with the reduction gear 6 is configured to provide synchronous rotation of the propellers 1 with a gear reduction gear 6 of a gear ratio of 8:1, maintaining the symmetry of forces, wherein the axes of rotation of the propellers 1 are made horizontally directed and co-directed with the fuselage of the ornithopter 2, minimizing resistance and providing vertical movement of the blades, the propellers 1 are secured to the fuselage of the ornithopter 2 through brackets 9 at a distance for a clean flow, wherein the brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, with bearings for rigidity and damping, each propeller 1 contains eight blades 3, for smoothed pulsations of the lifting force and vibration suppression, the blades 3 of the propellers 1 are made with rounded ends, minimizing induced drag and turbulence, increasing the lifting force and stability.

[0087] The fifth example of the implementation of an ornithopter propulsion system is a variant for a manned apparatus weighing 300 kg, oriented towards recreational flights with a focus on safety. The propulsion device includes paired propellers 1, a swash plate 4, cardan shafts 5, a gearbox 6, an engine 7, wherein each propeller 1 contains blades 3, which are made with an aerodynamic profile, symmetrical for versatility in different modes, in addition, the blades 3 are made with the ability to change the angle of attack using the swash plate 4 by 10-90 degrees, simulating the biomechanics of flight with disturbance compensation, the swash plate 4 contains a rotary mechanism 10, on which the blade mounting hub 8 is mounted, integrating control for precise adaptation, also the blade mounting hub 8 is connected to the cardan shafts 5, which are connected to the gearbox 6, which is connected to the engine 7, with vibration absorption for reliability,The engine 7 together with the gearbox 6 is configured to provide synchronous rotation of the propellers 1 through the combined gearbox 6 with a gear ratio of 6:1, ensuring balance, wherein the axes of rotation of the propellers 1 are made horizontally directed and co-directional with the fuselage of the ornithopter 2, for symmetrical generation of force, the propellers 1 are fixed to the fuselage of the ornithopter 2 through brackets 9 with shock absorbers, wherein the brackets 9 are installed perpendicular to the fuselage of the ornithopter 2 and the axes of rotation of the propellers 1, ensuring the stability of the structure, each propeller 1 contains ten blades 3, maximizing the uniformity of the lifting force for a smooth flight, the blades 3 of the propellers 1 are made of composite materials, such as fiberglass, for lightness and strength, with a length of 5 m and a width of 0.2-0.5 m, adapted for safety and efficiency.

[0088] Based on the technical result, a comparative analysis of the claimed invention was conducted with similar devices and the prototype. The analysis included a check of the lift coefficient (CL, dimensionless), the efficiency coefficient (the ratio of lift to power consumption, dimensionless), and the flight stability level (measured as a deviation from the specified trajectory as a percentage of the nominal altitude and heading during a 10-minute test flight, %).

[0089] For objective comparison, all devices were tested under the same conditions: ornithopter weight of 100 kg, flight speed of 50 km / h, atmospheric conditions (temperature +15°C, wind up to 5 m / s), propeller speed up to 300 rpm (adapted for each analogue), engine power of 50 kW; tests were carried out in a wind tunnel with subsequent flight simulation in CFD (Computational Fluid Dynamics) software to measure aerodynamic forces and in real test flights at the test site to evaluate stability, using accelerometers, gyroscopes and GPS sensors to record vibrations, roll, yaw and lift.

[0090] US 2003226933 A1 had a lift coefficient of 1.2, an efficiency coefficient of 0.6, and a 15% yaw rate, due to the reliance on reciprocating wings without synchronous rotation, resulting in unbalanced vertical impulses and the need for additional counter-rotation devices to compensate for torque, resulting in increased vibrations and a 10-12% altitude loss per cycle in test flights, and reduced lift in CFD simulations due to inefficient flapping in the ascending phase.

[0091] CN 218559175 U has a lift coefficient of 1.3, an efficiency coefficient of 0.65, and a trajectory deviation level of 12%, which is due to the use of deformable blades with variable twisting without paired synchronous elements, causing uneven load distribution and vibration in transient conditions. In the wind tunnel, losses due to inefficient flapping of up to 8-10% were recorded, and in real flights, roll and yaw occurred without additional stabilizers, leading to overall instability at the level of 10-15% deviation.

[0092] CN 112429227 A has a lift coefficient of 1.4, an efficiency coefficient of 0.7, and a trajectory deviation rate of 10%, which is determined by the linear flapping motion without paired rotating elements, resulting in asymmetric loads and vibrations in the cycle. In CFD analysis, the lift was reduced by 5-7% due to vibration losses, and test flights showed instability with roll and yaw, requiring collective angle control to compensate, but without complete balancing.

[0093] At the same time, the claimed invention has a lift coefficient of 1.8, an efficiency coefficient of 0.85, and a trajectory deviation level of 4%, which is achieved through twin propellers with synchronous rotation, a swash plate for differentially changing the angle of attack of the blades and horizontal axes, an optimized lift force with minimal losses in the ascending phase was recorded in the wind tunnel, and in real flights, moment balancing was ensured without additional systems, with vibration damping by dampers and a symmetrical distribution of forces.

[0094] Thus, the claimed invention increases the lift coefficient of the ornithopter in comparison with analogs and the prototype by 20-30%, the efficiency coefficient by 15-25% and reduces the level of deviation from the trajectory by 50-70%, ensuring the best flight stabilization.

Claims

1. Ornithopter propulsion system, including twin propellers, swash plate, cardan shafts, gearbox, engine, each propeller contains blades that are made with an aerodynamic profile, In addition, the blades are designed with the ability to change the angle of attack by 10-90 degrees using a swash plate, the swash plate contains a rotating mechanism on which the blade mounting hub is mounted, also the blade mounting hub is connected to the cardan shafts, which are connected to the gearbox, which is connected to the engine, the engine, together with the gearbox, is designed to ensure synchronous rotation of the propellers, while the axes of rotation of the propellers are made horizontally directed and co-directed with the fuselage of the ornithopter, The propellers are secured to the ornithopter fuselage via brackets, with the brackets installed perpendicular to the ornithopter fuselage and the propeller rotation axes.

2. An ornithopter propulsion device according to paragraph 1, characterized in that each propeller contains from 2 to 10 blades.

3. An ornithopter propulsion device according to paragraph 1, characterized in that the propeller blades are designed to rotate at up to 300 rpm.

4. An ornithopter propulsion device according to paragraph 1, characterized in that the propeller blades are made of composite materials.

5. An ornithopter propulsion device according to paragraph 1, characterized in that the blades are made from 1.0 to 15 m long and from 0.2 to 0.5 m wide.

6. An ornithopter propulsion device according to paragraph 1, characterized in that the propeller blades are made with rounded ends.

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