RU2808290C1 - Combined dynamically scaled aerodynamic model for different types of aerodynamic tests - Google Patents

Abstract

FIELD: aerodynamic models.

SUBSTANCE: design of aerodynamic models used for experimental studies in industrial aerodynamics wind tunnels. The aerodynamic model of an aircraft consists of a fuselage, wing consoles with aerodynamic control surfaces and takeoff and landing mechanization, detachable engine nacelles, a detachable vertical fin with controlled rudders and a rotating, detachable horizontal fin with controlled rudders. The fuselage consists of a force floor to which frames and a force base plate are attached, with a force frame and force braces attached to it. Coverings are attached to the load-bearing floor and frames, to which covers are attached for various types of tests.

EFFECT: developing a standard design of a dynamically scaled aerodynamic model, adaptable to an aircraft in any aerodynamic configuration and expanding the number of special devices designed for mounting one model in different aerodynamic wind tunnels.

20 cl, 18 dwg

Description

The invention relates to aerodynamic model designs intended for testing in wind tunnels.

The creation of new generation aircraft is based on various experimental research methods, such as mathematical modeling and various types of tests in wind tunnels.

As a rule, such experiments in wind tunnels make it possible to obtain a wide range of experimental data on models, while they are more economical, visual and safe compared to flight studies.

When creating aerodynamic models of new aircraft, many technical problems arise. These problems lead to the fact that the process of aerodynamic testing using an aerodynamic model of an aircraft turns into a lengthy procedure associated with lengthy preparatory work. Often in the process of these works it is necessary to use unique holders and brackets to attach the aerodynamic model of the aircraft to the elements of the scales of a specific working part of the wind tunnel. Traditionally, to support various types of testing, a family of unique aerodynamic models of the aircraft under test are manufactured, each of which is prepared for the specific supporting devices of a particular wind tunnel and meets the required specifications for a particular wind tunnel.

An aerodynamic model of an aircraft made of photopolymer material is known (RF patent No. 2453820, June 20, 2012), consisting of the bow and tail parts of the fuselage with engine nacelles and tail surfaces. The disadvantage of this aerodynamic model is the impossibility of manufacturing aircraft models with fasteners for replaceable mechanization parts, since the structural material from which this model is made has low strength, for this reason the model can collapse under the influence of low air flow loads. A disadvantage should also be considered the lack of mechanization elements, such as: elevators, rudders, ailerons, flaps due to insufficient strength when manufactured from photopolymers.

The design of an aerodynamic model is known (RF patent No. 2417358, 04/27/2011), which has an integrated fuselage with a wing, front horizontal and tail surfaces, as well as parts with boundary layer drain channels, parts with internal ducts of engine channels and a nose fairing. Parts for this model are molded from carbon fiber in a special mold, dividing it into upper and lower parts.

The disadvantage of this design is the design of the wings and tail surfaces without the use of moving mechanization elements, as well as the impossibility of installing fasteners inside the fuselage for testing in other wind tunnels.

A universal aerodynamic model and a method for its manufacture are known (RF patent No. 2083967, 07/10/1997). The model contains an elastic frame and a composite material skin connected to the frame beams by means of ribs. The casing consists of a main and an additional section. The main section of the skin, for example, the wing, and the lower - additional section of the skin, adjacent to the main one with the formation of cracks, are reinforced in the form of a crust of polymer material (for example, polystyrene foam). The additional section of the skin and parts of several split ribs are connected to the main section and parts of the ribs using a locking device. During the manufacturing process of the model, the rigidity characteristics of the elastic frame, for example, a wing spar, are measured. To form the skin along the entire contour of the profile, a foam core is glued to the ribs and covered with a transparent layer of composite material.

The disadvantage of this design is the lack of mechanization elements in the wing and tail.

A known design, such as a structurally similar aerodynamic model and a method for its manufacture, is given in the book by R.E. Lamper, V.V. Lyshchinsky. "Introduction to flutter theory and modeling." Novosibirsk, 1999, fig.5.10, p.93. A similar model is made of thin-walled metal.

The disadvantage of such a model is its high technological complexity, since metal parts must first be stamped in special molds and then welded in a special slipway to reduce the leash.

The design of a non-separable elastic-like model is known, obtained by milling or molding the core of the model with the application of an external foam coating. Information about this model is given in the book by R.L. Bisplinghoff, H. Ashley, R.L. Halfman. Aeroelasticity. M., IL, 1958. The model has a drawback, since it does not allow the formation of mechanization controls in its internal space, the placement of special loads to simulate the flight weight of the aircraft and its alignment.

The known “Universal elastic-like aerodynamic model and method of its manufacture (RF patent No. 1454646, 06/27/2012). In this patent, the wing and tail is a structure in the form of a power core, made in the form of a profiled small part of the outer upper surface and a part of the profiled lower surface of the wing. A removable cover is attached to the core with screws. The removable cover is made in the form of a load-bearing surface, but narrower than part of the upper surface of the wing or horizontal tail. The cover is made of low-modulus filler such as foam plastic or model plastic, covered on the outside and inside with unidirectional composite fabric.

The disadvantage of this design is that this design is typical for models with a smooth wing or tail profile, without taking into account mechanization elements such as elevators, directions, ailerons, slats, spoilers. With this design it is impossible to control changes in the profile of the load-bearing surfaces.

The closest in technical essence to this invention is the design described in RF patent No. 2607675 C1, 01/10/2017. According to the description, the aerodynamic model of the aircraft consists of a fuselage, wing, tail unit and skin, connected to each other by separate cores. The wing and tail of such an aerodynamic model have movable remote-controlled mechanization. Inside the wing of this aerodynamic model there are special weights that simulate the different weights of gas tanks with fuel.

The disadvantages of this aerodynamic model design are the impossibility of testing at high angles of attack in a gimbal, as well as in free spin conditions.

To eliminate the influence of production errors in the manufacture of different models and reduce the cost of an aerodynamic experiment, it becomes relevant to use one combined aerodynamic model for testing in different wind tunnels.

The objective of this invention is to increase the level of adequacy of aerodynamic experiments, increase the level of information content of an aerodynamic experiment, reduce the time of experimental research and, as a result, reduce the cost of experimental research, increase the versatility of the aerodynamic model by introducing removable elements into its design, providing the ability to conduct several types of tests in various wind tunnels.

The technical result consists in developing a standard design of a dynamically similar aerodynamic model, adaptable to an aircraft in any aerodynamic configuration and expanding the number of special devices designed for mounting one model in different wind tunnels.

The technical result is achieved thanks to the following set of features.

An aerodynamic model of an aircraft, consisting of a fuselage, wing consoles with aerodynamic control surfaces and takeoff and landing mechanization, detachable engine nacelles, a detachable vertical tail with controllable rudders and a rotating, detachable horizontal tail with controllable rudders. The fuselage consists of a force floor, to which frames and a force base plate are attached, with a force frame and force braces attached to it; skins are attached to the force floor and frames, to which covers are attached for various types of tests.

The power base plate is made with the possibility of attaching in-model experimental equipment to it.

The fuselage skins and covers are made with the ability to install and secure on them the grips of a pendulum device, which makes it possible to determine the moments of inertia of the aerodynamic model by the method of torsional vibrations.

The force floor of the fuselage is made with the ability to install and secure on it the nose, central and tail fuselage weights, designed to adjust the position of the model's center of gravity and reproduce the moments of inertia of the aerodynamic model to simulate flight at different altitudes and with different flight weights.

The fuselage frames are made with the possibility of attaching clamping collets to them, with the help of which the rods of the aerodynamic control surfaces are fixedly fixed.

The load frame is configured to attach to it a bracket with a suspension cable hinge for testing the aerodynamic model in free spin conditions.

The power base plate of the fuselage is made with the possibility of attaching to it a three-degree hinge, which allows for an arbitrary position of the aerodynamic model relative to the air flow when simulating piloting of the aerodynamic model in the working part of the wind tunnel, or a single-degree hinge for rotating the aerodynamic model around its transverse axis when studying weight characteristics, or a tail support adapter to study the weight characteristics of the aerodynamic model during cruising flight, as well as a measuring inertial control system to control the servos driving the aerodynamic control surfaces during testing.

Each wing console is made with the possibility of installing a removable engine nacelle on it with or without a pylon, as well as attaching to it, by means of fasteners, grips of a pendulum device for conducting an experiment that allows determining the moments of inertia of the aerodynamic model by the method of torsional vibrations.

The aerodynamic surfaces on each wing console, controlled by a tubular shaft using rollers and cables, are designed to be deflected by means of a servo drive, or rigidly fixed at a given angle by means of a collet clamp.

Each wing console contains containers for placing wing weights in them, designed to realize the moments of inertia of the aerodynamic model when simulating the flight of an aircraft at different altitudes and with different flight weights, as well as holes for installing removable templates with engraving of angular sectors, allowing you to adjust correction factors in control system and accurately set the deflection angles of the aerodynamic control surfaces when preparing the model for aerodynamic tests.

The rudder located on the detachable vertical tail is designed to be deflected to a given angle by means of a steering gear mounted inside the vertical tail, or rigidly fixed by a clamping collet in a certain specified position.

The detachable vertical tail contains holes for installing a removable angular sector, which allows you to control the rudder deflection angles to adjust the control system before aerodynamic tests.

The horizontal tail consists of two stabilizer consoles, each of which can be independently rotated around its axis and rigidly fixed with clamping collets in a certain specified position relative to the horizontal fuselage.

The elevators located on each stabilizer console are designed to be deflected to a given angle by the corresponding steering machines fixed inside the fuselage, or rigidly fixed by the corresponding clamping collet rockers of the elevators in a certain specified position.

Each stabilizer console contains holes for installing removable corner sectors, allowing you to control the deflection angles of the elevators when preparing the model for aerodynamic tests.

As an example, consider a model of the layout of a passenger airliner.

The design of the model is shown in the following illustrations.

Fig. 1 General view of the aerodynamic model

Fig. 2 Scheme of fastening the frames and base plate to the load-bearing floor.

Fig. 3 General view of the fuselage skins and covers.

Fig. 4 Wing console structure.

Fig. 5 Scheme of fastening the movable aileron.

Fig. 6 Scheme of attaching the pylon with the engine nacelle to the wing.

Fig. 7 Scheme of fastening the mechanization elements to the wing.

Fig. 8 Scheme of attaching the wing to the fuselage.

Fig. 9 Arrangement of detachable vertical tail.

Fig. 10 Connection diagram of the steering machine with the rudder.

Fig. 11 Horizontal tail unit.

Fig. 12 Scheme of controlling elevators using steering gears.

Fig. 13 Scheme of control of elevators by rods and collets.

Fig. 14 Scheme of cargo placement in wing consoles and fuselage parts.

Fig. 15 Scheme of fastening the fuselage to the grips of the pendulum device.

Fig. 16 Scheme of attaching the wing to the grips of the pendulum device.

Fig. 17 Diagram of installation of a corner sector for monitoring the angles of deflection of mechanization elements.

Fig. 18 Types of various hinge devices fixed inside the fuselage.

The aerodynamic model consists of: fuselage 1, wing consoles 2 with engine nacelles 47, detachable vertical tail 3 and rotating horizontal tail 4 (Figure 1). The aerodynamic control surfaces are 35 ailerons, 71 rudders, 88 elevators, and 57 spoilers.

Inside the fuselage there is a force floor 5, made of a polymer composite material, in which bushings 6 (for example, metal) are installed for fastening removable elements (Fig. 2). Frames 7, 8, 9, 10, 11, made, for example, of polymer composite materials, and a base plate 12, made, for example, of a metal alloy, are attached to the load-bearing floor. Metal power braces 13 and a metal power frame 14 connected to each other are attached to the base plate 12. A metal bracket 15 is attached to the load frame 14. Metal clamping collets 16 are installed on frames 8 and 11.

The fuselage surface consists of: side skins 17, 18, covers 19, 20. The skins are attached to the load-bearing floor 5 and frames. Depending on the type of test, the model is equipped with covers 21a, 21b, 22a, 22b, 22c, 22d, 23a, 23b, 24, 25a, 25b (Figure 3), which are attached to the casings. All fuselage skins and covers are made of polymer composite materials.

Each wing console of the aerodynamic model consists of an upper skin 26, a lower skin 27, a spar 28, a rear wall 29, a trailing edge 30, which are made of polymer composite materials (Figure 4). The nose liner 31 and ordinary ribs 32, made, for example, of wood, are glued to the spar 28. Between the spar 28 and the rear wall 29, a power rib 33, made, for example, of wood, is glued. At the end of the console, an end piece 34, made, for example, of wood, is glued.

On each wing console, ailerons 35 are installed (Fig. 5), made, for example, from polymer composite materials. They are mounted on axles 36 and 37. Axle 36 passes freely through the loop 38 of the aileron 35. Axle 37 passes freely through the loop of the wing 39. A driven roller 40 is fixed to the axis 37, which is simultaneously rigidly connected to the aileron 35. The driven roller 40 is controlled by cable wiring 41 from the drive roller 42. The drive roller 42 is rigidly connected to the tubular shaft 43. By rotating the tubular shaft 43 through the cable wiring 41, the deflection of the aileron to a given angle relative to the wing console is controlled. The driven roller 40, the drive roller 42 with a tubular shaft 43 and cable wiring 41 are installed in unit 44, which is located inside each wing console.

Separable pylons 46 with engine nacelles 47 are attached to the power rib 33 of each wing console with screws 45 (Fig. 6). For a configuration without a pylon, the attachment occurs directly to the engine nacelle with 47 screws 45. The configuration without a pylon is used for aircraft models, for example, with turboprop engines. Detachable brackets 49 are attached to the nose liner 31 with screws 48 for installing slats 50 (Fig. 7). In turn, the slats 50 are fixed to the brackets 49 using screws 51. By replacing some brackets 49 with others, the wing is tested with the slats 50 located at different angles and at different distances from the nose of the wing.

Detachable brackets 53 are attached to the ordinary ribs 32 with screws 52. Flaps 55 are attached to the brackets 53 with screws 54. Detachable spoilers 57 are attached to the ordinary ribs 32 with screws 56. The wing consoles are attached to the base plate 12 of the power floor 5 with screws through holes 58 , 59 using tabs 60 and 61 (Fig. 8).

The detachable vertical tail 3 is assembled from keel skins 62 and 63, leading edge 64, trailing edge 65, ribs 66 (Fig. 9). All of them are made, for example, from polymer composite materials. On the trailing edge 65 there are hinges 67 and 68, in which the rudder 71 is rotated on axes 69 and 70. To rigidly fix the rudder 71 relative to the keel skins, a clamping collet 72 is used, which secures the axis 69 with screws 73. Fastening, for example, with screws The detachable vertical tail is carried out on the fuselage through holes 74 made in the fin skins 62 and 63.

The rudder 71 is deflected to the desired angle by a steering machine 75 mounted on a bracket 76 (Fig. 10). In turn, the bracket 76 is secured inside the detachable vertical tail. The rocker 77 of the steering engine 75 is connected by an articulated rod 78 to the rocker 79. The rocker 79 is secured to the axis 69 of the detachable vertical tail.

The rotating horizontal tail 4 is made in the form of an adjustable stabilizer consisting of two consoles. Each console of the adjustable stabilizer consists of: upper skin 80, lower skin 81, regular ribs 82, trailing edge 83 (Fig. 11). All of them are made, for example, from polymer composite materials. The axes of the consoles 85 of the adjustable stabilizer are fixed in the root ribs 84. The axes of the consoles 85 of the adjustable stabilizer pass through the corresponding clamping collets 86, mounted on the inner surface of the side skins 17 and 18 of the fuselage. Clamping collets 86 allow you to change and then rigidly fix the required angle of deflection of the right or left console of the adjustable stabilizer relative to the horizontal plane of the fuselage. Inside the fuselage, the axles of the consoles 85 are connected to each other by a coupling 87.

Each of the elevators 88, mounted on axles 89 and 90, is deflected relative to the outer surface of the corresponding stabilizer console. To ensure the deflection of each elevator to the required angle, clamping collet rockers 91 are fixed on each of the axes 90.

To remotely control the deflection of the elevators 88 of the right or left console of the adjustable stabilizer during remote piloting tests, steering gears 92, with rockers 93 and rods 94 are used (Fig. 12). To mechanically fix each of the elevators during weight tests, rods 95, 96 and clamping collets 16 are used (Fig. 13).

Before carrying out tests that require mass-inertial similarity of the aerodynamic model in a specific wind tunnel, it is loaded with removable wing weights 97 and 98, and/or forward fuselage weight 99, and/or central fuselage weights 100 and/or tail fuselage weight 101, which allow adjust the given mass-inertial characteristics of the aerodynamic model and, thereby, simulate the flight of an aircraft at different altitudes and with different flight weights (Fig. 14). Loads are placed and secured in special designated areas of the wing and fuselage.

Loads of various masses make it possible to create the necessary moments of inertia of the aerodynamic model, the compliance of which is checked by the method of torsional vibrations on a pendulum device 102 (Fig. 15). To do this, the grips 103 of the pendulum device 102 are attached to the fastening elements 104 mounted on the fuselage of the aerodynamic model. In another case, the grips 103 of the pendulum device 102 are attached to the fastening elements 105 mounted on the wing consoles 2 (Fig. 16).

On the outer surfaces of the wing consoles 2, vertical tail 3 and horizontal tail consoles 4 there are holes 106 into which corresponding metal templates are installed with graduation of angular sectors 107 (Fig. 17). Using templates of angular sectors 107, the deflection angles of the ailerons 35, rudder 71, and elevators 88 are controlled before starting aerodynamic tests of the aerodynamic model. During aerodynamic testing, corner sectors are not used, and holes 106 are closed to ensure the smoothness of the outer surface of the aerodynamic model.

To install an aerodynamic model in the working part of a specific wind tunnel, in-model experimental equipment is installed inside the fuselage, in particular, various brackets (Fig. 18). So, for example, to test an aerodynamic model for a free spin, a metal bracket 15 is attached to the power frame 14, to which the suspension cable hinge 108 is in turn attached.

In-model experimental equipment may also include an air pressure switch for measuring the distribution of aerodynamic pressure on the surface of the model and a system of air routes; electric regulators, when installing power plant simulators based on electric motors; rechargeable batteries; weights designed to adjust the position of the model’s center of gravity and reproduce the moments of inertia of the aerodynamic model to simulate flight at different altitudes and with different flight weights; intra-model measuring control system; electric servo drives of the control system; control system collet clamps; mounting brackets for experimental equipment.

For example, to ensure a given position of the aerodynamic model in the air flow inside the fuselage, a three-degree hinge 109 is installed on the base plate 12, which allows remote piloting of the aerodynamic model, or a single-degree hinge (not shown in the figure) to allow the aerodynamic model to rotate around it. transverse axis when studying weight characteristics. Inside the fuselage, on the base plate 12 of the aerodynamic model, strain gauge scales 110 can be installed, allowing the aerodynamic model to be oriented around the longitudinal axis for carrying out weight tests with and without rotation of the model around the velocity vector. To study the weight characteristics in a wide range of angles of attack, a holder 111 is installed on the base plate 12, with the ability to change the angle of attack. To study the weight characteristics during the cruising test mode, the adapter 112 of the tail support 113 is fixed to the base plate 12 in the fuselage of the model. Testing under conditions of a free spin and simulated flight at high angles of attack is carried out when an inertial measurement control system 114 is installed on the power base plate 12.

Thus, the proposed model has a design with minimal mass, with empty internal volumes for the possibility of placing in-model experimental equipment and balancing weights for adjusting the mass-inertial characteristics. The model provides the ability to carry out tests in a wind tunnel not only assembled, but also without its individual elements, for example, a fuselage without tail, a wing without engine nacelles, etc.

A device for remote control of the deviation of many elements of mechanization, a spatial position module and a data transmission system are installed inside the model. The complex internal layout ensures compliance with inertial and weight similarity.

A universal design of the model has been created, adaptable to an aircraft in any aerodynamic configuration, with a detachable vertical tail, removable pylons and engine nacelles, replaceable brackets with mechanization elements, replaceable wiring systems for controlling aerodynamic surfaces, ensuring various types of aerodynamic experimental studies in different wind tunnels.

Several aerodynamic models of this class were manufactured and successfully tested in TsAGI wind tunnels, in particular, in the T-102, T-103, T-105 wind tunnels.

Claims (20)

1. An aerodynamic model of an aircraft, consisting of a fuselage, wing consoles with aerodynamic control surfaces and takeoff and landing mechanization, detachable engine nacelles, a detachable vertical tail with controllable rudders and a rotating, detachable horizontal tail with controllable rudders, characterized in that the fuselage consists of a power the floor, to which the frames and the power base plate are attached, with the power frame and power braces attached to it; skins are attached to the power floor and frames, to which covers are attached for different types of tests. 2. The aerodynamic model according to claim 1, characterized in that the power base plate is made with the possibility of attaching in-model experimental equipment to it. 3. The aerodynamic model according to claim 1, characterized in that the fuselage skins and covers are made with the ability to install and secure on them the grips of a pendulum device, which makes it possible to determine the moments of inertia of the aerodynamic model using the torsional vibration method. 4. The aerodynamic model according to claim 1, characterized in that the force floor of the fuselage is made with the ability to install and secure on it the bow, central and tail fuselage weights, designed to adjust the position of the model’s center of gravity and reproduce the moments of inertia of the aerodynamic model to simulate flight at different altitudes and with different flight weights. 5. The aerodynamic model according to claim 1, characterized in that the fuselage frames are made with the possibility of attaching clamping collets to them, with the help of which the rods of the aerodynamic control surfaces are fixedly fixed. 6. The aerodynamic model according to claim 1, characterized in that the load frame is configured to attach to it a bracket with a suspension cable hinge for testing the aerodynamic model in free spin conditions. 7. The aerodynamic model according to claim 2, characterized in that the power base plate of the fuselage is made with the possibility of attaching a three-degree hinge to it, which allows for an arbitrary position of the aerodynamic model relative to the air flow during simulated piloting of the aerodynamic model in the working part of the wind tunnel. 8. The aerodynamic model according to claim 2, characterized in that the force base plate of the fuselage is made with the possibility of attaching a single-degree hinge to it for rotating the aerodynamic model around its transverse axis when studying weight characteristics. 9. The aerodynamic model according to claim 2, characterized in that the force base plate of the fuselage is made with the possibility of attaching a tail support adapter to it to study the weight characteristics of the aerodynamic model during cruising flight mode. 10. The aerodynamic model according to claim 2, characterized in that the power base plate of the fuselage is made with the possibility of attaching to it a measuring inertial control system for controlling servos that drive the aerodynamic control surfaces during testing. 11. The aerodynamic model according to claim 1, characterized in that each wing console is made with the possibility of installing a removable engine nacelle on it with or without a pylon. 12. The aerodynamic model according to claim 1, characterized in that each wing console is made with the possibility of attaching to it, by means of fastening elements, grippers of a pendulum device for conducting an experiment that allows determining the moments of inertia of the aerodynamic model by the method of torsional vibrations. 13. The aerodynamic model according to claim 1, characterized in that the aerodynamic surfaces on each wing console, controlled by a tubular shaft using rollers and cables, are designed to be deflected by means of a servo drive, or rigidly fixed at a given angle by means of a collet clamp. 14. The aerodynamic model according to claim 1, characterized in that each wing console contains containers for placing wing weights in them, designed to realize the moments of inertia of the aerodynamic model when simulating the flight of an aircraft at different altitudes and with different flight weights. 15. The aerodynamic model according to claim 1, characterized in that each wing console contains holes for installing removable templates with engraving of angular sectors, which allow you to adjust correction factors in the control system and accurately set the deflection angles of the aerodynamic control surfaces when preparing the model for aerodynamic tests. 16. The aerodynamic model according to claim 1, characterized in that the rudder located on the detachable vertical tail is designed to be deflected to a given angle by means of a steering gear mounted inside the vertical tail, or rigidly fixed by a clamping collet in a certain specified position. 17. The aerodynamic model according to claim 16, characterized in that the detachable vertical tail contains holes for installing a removable angular sector, which allows you to control the rudder deflection angles to adjust the control system before aerodynamic tests. 18. The aerodynamic model according to claim 1, characterized in that the horizontal tail consists of two stabilizer consoles, each of which can be independently rotated around its axis and rigidly fixed with clamping collets in a certain specified position relative to the building horizontal of the fuselage. 19. The aerodynamic model according to claim 18, characterized in that the elevators located on each stabilizer console are designed to be deflected by a given angle by the corresponding steering machines fixed inside the fuselage, or rigidly fixed by the corresponding clamping collet rockers of the elevators in a certain specified position. 20. The aerodynamic model according to claim 18, characterized in that each stabilizer console contains holes for installing removable corner sectors that allow you to control the deflection angles of the elevators when preparing the model for aerodynamic tests.