WO2016175676A1

WO2016175676A1 - Aircraft with canard configuration

Info

Publication number: WO2016175676A1
Application number: PCT/RU2015/000703
Authority: WO
Inventors: Юрий Константинович КРАСНОВ
Original assignee: Юрий Константинович КРАСНОВ
Priority date: 2015-10-26
Filing date: 2015-10-26
Publication date: 2016-11-03

Abstract

An aircraft having a canard aerodynamic configuration (see fig. 4) comprises a mechanized wing, which is not shown in the drawing, and also a canard foreplane (10) with a servo flap (3), which are pivotally mounted on the axis of rotation ОО¹. The lift coefficient derivative of the canard foreplane with respect to the angle of attack of the aircraft increases from zero to the required amount as a result of the angle between the reference planes of the canard foreplane (10) and the aircraft changing relative to only a part of the change in the angle between the reference planes of the servo flap (3) and the aircraft as the angle of attack of the aircraft changes. To this end, a mechanism consisting of elements (11), (12) and (13) is used. For pitch control, the axis ОО³ can be displaced towards axis ОО¹ or away from same, and the position thereof is fixed by a rod (14), which is an element of the control system. The invention is directed toward reducing the area of the wing by equalizing the cruise workload of the canard foreplane therewith.

Description

FLIGHT VEHICLE DIAGRAM

Technical field

The present invention relates to aeronautical engineering, and more specifically to apparatus heavier than air, namely, made according to the aerodynamic design of “weathervane duck” and can be used in the construction of any aircraft for increasing their efficiency. State of the art

Known aircraft (LA) aerodynamic scheme "duck" containing bearing surfaces in the form of a mechanized wing and front horizontal tail (PGO), rigidly connected with the fuselage and executed on a biplane scheme (see, for example, PCT application international publication number WO 93 / 17909).

Such a scheme was born from the desire of designers to get rid of the balancing resistance created by the downward aerodynamic force arising on the horizontal tail of the aircraft of the “normal” scheme. Despite the fact that the first flying aircraft was made exactly according to the “ka” scheme, this scheme is not widely used to date. The reason for this is the extreme complexity, and sometimes the inability to use the means to increase the lifting force of the wing or, in other words, the mechanization of the wing. It is enough to note that in all completed projects of the “ducks” of the famous designer Rutan (Elbert Rutan), the wing did not even have such elementary mechanization as a simple flap. In high-speed maneuverable jet planes of the duck scheme, for example, Grippen (Sweden), Rafale (France), Typhoon (Europe) and others, this drawback of the duck scheme is eliminated through the use of very complex automatic control systems and sustainability. Passenger and transport aircraft must necessarily have a certain margin of static stability (and for maneuverable fighters, if there is one, it will not be superfluous), and this fact currently prevents the use of wing mechanization.

In the future, we will consider only statically stable aircraft. The reasons for the impossibility of using wing mechanization in statically stable "ducks" are as follows.

The moment of pitch of the lifting force of the wing relative to the center of mass of the aircraft must be balanced by the moment of pitch of the lifting force of the front horizontal tail of the PGO.

SUBSTITUTE SHEET (RULE 26) Ha FIG. 1 is a diagram of the lifting forces acting on an airplane in a steady horizontal cruising flight.

Here, the letter Lp denotes the wing lift applied at the focus ACP of the wing. The focus is the point of application of increments of the lifting forces caused by a change in the angle of attack of the aerodynamic surface or aircraft.

The lifting force of the PGO Ls is the sum of the Los force that occurs when the angle of attack is equal to the angle of attack of the wing (aircraft) and applied in focus ACs of the PGO. The Los force is part of the resultant force L applied at the AC point, which is the focal point of the aircraft. Another component of the force L is the wing lift Lp. The forces Lp and Los have the same nature, namely, they are the result of an increase in the angle of attack of the wing and PGO from the angle at which the wing and PGO have zero lift to the cruising angle of attack of the wing.

Since the PGO installation angle exceeds the wing installation angle, due to the difference in the PGO and airplane attack angles, an additional force arises on the PGO, denoted as Lbals, called balancing by the author, and it is applied in the focus of the ACs of the PGO. This force is not included in the resultant force L applied in the focus of the aircraft AC.

The CG center of mass of the aircraft is located in front of the focus of the aircraft AC at a distance of O, which is 5-10 percent of the average aerodynamic chord (SAX) of the wing. This distance is called the margin of safety overload. In the center of the mass CG, a downward gravity force W of the aircraft is applied.

Due to the fact that the force L and gravity force W of the aircraft are multidirectional and applied at different points, a diving moment arises, and this moment is compensated by the moment of balancing force Lbals. The same moment additionally compensates for the zero diving moment of the wing (the moment of the wing with its zero lifting force).

The sum of the forces Lp, Los and Lbals modulo equal to the gravity force W of the aircraft.

The reasoning given on this page is also valid for the normal scheme, taking into account that the focus of the aircraft is not shifted forward, but backward, following the stabilizing surface. In this case, the difference between the angle of attack of the wing and the stabilizer is negative and negative is Lbals. They are given in order to clarify the physics of aircraft balancing as much as possible. In the available literature, these explanations are present, but in a mathematically veiled form.

The ratio of the shoulder Bs of the lifting force of the PGO and the shoulder Bp of the wing of the considered “duck” is such that it imposes a limit on the maximum lifting force of the wing. Moreover, at large angles of attack, _w

- 3 - for example, landing and maneuvering, that is, when the elevators are completely deflected, the PGO lifting force is fully used. To use the lifting force of the wing as much as modern means of mechanization of the wing allow, does not allow too large shoulder lifting force of the wing.

Given that

and the overwhelming part of the wing lift arm Bp is the distance ΔΧ between the foci of the wing and the airplane, we consider in detail this quantity, which is usually called the focus shift.

In a first approximation, the focus shift is directly proportional to the product of the distance between the foci of the wing and the PGO by the ratio of the areas of the PGO and the wing. Additionally, and this is very important, the focus shift increases along with the increase in the derivative with respect to the angle of attack of the PGO lift coefficient. The above is mathematically expressed by the following formula:

where AH is the distance between the foci of the wing and the plane (focus shift);

In - the distance between the foci of the wing and PGO

S is the ratio of the area of the PGO and the wing;

C ^a Is; C ^a Ip are the derivatives with respect to the angle of attack of the lift coefficients for the PGO and the wing, respectively. For brevity, we will call them the derivative of the VGO and the derivative of the wing.

It can be clearly seen from the above formula that neither an increase in the area of the PGO, nor an increase in the distance between the foci of the wing and the PGO, will improve the situation, since with their increase the focus shift, and hence the wing shoulder, also increases. But it also clearly follows: if the derivative of the PGO lift coefficient with respect to the angle of attack is significantly reduced, the wing lift shoulder is significantly reduced; and if it is possible to significantly reduce the specified derivative of the PGO, this will allow the use of modern means of mechanization of the wing.

Another aerodynamic aircraft known

"Weathervane duck" containing bearing surfaces in the form of a mechanized wing and a vane anterior horizontal tail (FPGO) equipped with at least one servo-wheel (see, for example, RF patent JVs 2243131 C1).

In this aircraft, to reduce the specified derivative C ^a ls PGO, this

The PGO, in its traditional sense, was completely excluded from the aerodynamic design and replaced with a weathervane front horizontal plumage (FPGO), controlled by servo wheels functionally connected to the pitch control system. This FPGO is pivotally connected to the fuselage and, under the influence of servo-wheels, are set at a certain angle of attack to the oncoming air flow and thus creates lift. The angle of attack of the vane surfaces depends only on the angle established by the pilot between the base plane of the FPGO and the base plane of the servo wheel. And with the servo-wheel position unchanged relative to the FPGO base plane, this angle of attack is preserved in any case. Be it a change in the direction of the oncoming flow, or a change in the pitch angle of the aircraft itself, which is identical in physical essence. Essentially, the specified FPGO in this aircraft plays the role of bearing and steering surfaces that do not affect the focus position of the aircraft.

Along with the term "vane", another term identical to it is used, "floating".

It would seem that the goal has been achieved. FPGO creates lift, but does not respond to changes in the angle of attack of the aircraft and therefore has a derivative with respect to the angle of attack of the coefficient of lift in magnitude close to zero. But all over the Internet there is not a single video of the stable flight of such an aircraft. And here is an example of an unstable flight of such an aircraft: http://www.youfebe.com/watch?v=Lh8KRwaNFbQ htφ: //www.youtube.com/watch? V = EPfa5as () yMs

http.V / vnvw.youtobe.com / watch? v = aoKrhESMnQ4.

The reason for the longitudinal instability is, paradoxically, the "superstability" of such an aircraft. In an ordinary weft, with a margin of longitudinal stability overload equal to 10% С АХ, the stabilizing moment of pitch with an accidental increase in the attack angle of the aircraft by one degree without taking into account the pressure head, braking and bevel of the flow beyond the VSP is

(C «kS _s + C ^tt ip-Sp) -0, l -ba

where: Ss, Sp are the areas of PGO and wing, respectively

L - the average aerodynamic chord of the wing. The stabilizing moment for an airplane with a weather vane, which has a load similar in size to the wing, is as follows

As you can see, it significantly exceeds the value for an ordinary duck. As a result of this excessive stabilizing moment, the aircraft does not return to its previous mode, but “skips” it, as a result of which self-oscillations arise, which the pilot is unable to extinguish.

To exclude this phenomenon, in the prototype (see RF patent JVe

2243131 C1) vane PGO in cruise flight mode has a very low load, which is about a tenth of the wing load. Essentially, in the cruise flight mode, the aerodynamic design of such an aircraft is “tailless”, and the FPGO serves to provide the possibility of balancing during the release of wing mechanization. That is, in the main mode of operation of the aircraft FPGO actually does not work, but it has a certain aerodynamic drag, and this affects the performance of the aircraft. In addition, since the FPGO in the cruise flight mode carries an insignificant load, almost all the load falls on the wing, and therefore it should have a sufficiently large area.

Thus, we can conclude that modern aircraft "vane duck" scheme have a wing of too large area, and this increases the cost and operational characteristics of the aircraft.

Disclosure of invention

The present invention is the creation of such an aircraft scheme "weathervane duck", which due to the increase in congestion FPGO at cruising flight modes would significantly reduce the wing area.

This problem is solved by the fact that in the aircraft (LA) of the aerodynamic scheme "weathervane duck" containing bearing surfaces in the form of a mechanized wing and weathervane front horizontal tail unit (FPGO) equipped with at least one servo-wheel connected to the pitch control system, at least one bearing surface is equipped with a means of changing its lifting force, functionally dependent on changes in the angle between the base planes of the servo-steering wheel and the aircraft in such a way as to increase the derivative with respect to the angle of attack of the aircraft oeffitsienta lifting force to this supporting surface, if it is located in front of the aircraft's center of mass and reduce the specified derivative, if the surface is located behind the center of mass.

This can significantly reduce the wing area of the aircraft. To change the lifting force of the FPGO, it is equipped with a means of changing its lifting force, increasing its derivative with respect to the angle of attack of the aircraft, the lifting force coefficient, in the form of a elevator, the change in the angle of deviation of which is opposite and proportional to the change in the angle of deviation of the servo wheel relative to the base plane of the aircraft.

In another embodiment, the task is solved in that the FPGO is equipped with a means of changing its lift, increasing its derivative with respect to the angle of attack of the aircraft of the lift coefficient, in the form of an aggregate that changes the angle between the base planes of the FPGO and LA by a proportional part of the change in the angle between the base planes of the servo wheel and LA

The problem can be solved due to the fact that the mechanized wing is equipped with a means of changing its lift, decreasing its derivative with respect to the angle of attack of the aircraft of the lift coefficient, in the form of a elevator, the change in the angle of deviation of which is proportional to the change in the angle of deviation of the servo wheel relative to the base plane of the aircraft.

Brief Description of the Drawings

In the future, the patented invention is illustrated by specific examples of its implementation and the accompanying drawings.

FIG. 1 is a diagram of the lifting forces acting on an airplane in a steady horizontal cruising flight;

in FIG. 2 shows a variant of the FPGO equipped with a means of changing its lifting force in the form of a elevator, the change in the angle of deviation of which is opposite and proportional to the change in the angle of deviation of the servo wheel relative to the aircraft reference plane;

in FIG. 3 shows the configuration change of the PPGO shown in FIG. 2, due to a change in the angle of attack of the aircraft;

in FIG. 4 shows a variant of the FPGO equipped with a means of changing its lifting force in the form of an aggregate that changes the angle between the base planes of the FPGO and the aircraft by a proportional part of the change in the angle between the base planes of the servo steering wheel and the aircraft. The best embodiment of the invention

The inventive aircraft is made according to the aerodynamic scheme "weathervane duck", it contains bearing surfaces in the form of a mechanized wing and a weathervane front horizontal tail unit equipped with at least one servo wheel. In FIG. Figure 2 shows a variant of the FPGO equipped with a means for changing its lifting force in the form of a elevator, the change in the deviation angle of which is opposite and proportional to the change in the angle of deviation of the servo wheel relative to the aircraft reference plane.

FPGO 1 is pivotally connected to the fuselage not shown in the drawing along the geometric axis of rotation of OO ¹ , perpendicular to the plane of symmetry of the aircraft. A rod 2 with a servo wheel 3 is rigidly mounted on the same axis. The FPGO 1 and servo wheel 3 are able to freely rotate around the axis of OO ¹ , but they are interconnected in such a way that the pilot can set one or another angle between their base planes . The elevator 4 is pivotally connected to the FPGO 1 along the OO ² axis. On the elevator 4, the lever 5 is rigidly fixed, pivotally connected to the rod 6, it, in turn, is also pivotally connected to the lever 7. The lever 7 is pivotally placed along the geometric axis of OO ¹ . The position of the lever 7 is fixed pivotally connected to it by a rod 8, which is part of the pitch control system.

Arrow 9 indicate the direction of the oncoming air flow.

Regardless of the pitch angle of the aircraft as a result of the combined action of aerodynamic forces on the FPGO 1 and on the servo wheel 3, the FPGO 1 spontaneously sets at a certain angle of attack to the direction of the oncoming flow, indicated by arrow 9. At the same time, a lift force arises on the FPGO 1. It compensates for the diving moment of a wing not shown in the drawing. Due to the lifting force arising at FPGO 1, the aircraft can be balanced with increased wing lift due to mechanization.

If FPGO 1 did not change its lifting force with a change in the angle of attack, then its derivative would be equal to zero and a stable flight with its significant cruising load would be impossible. The value of the derivative of the PGO should be selected depending on the parameters of the wing and the desired position of the center of mass of a particular aircraft. An analysis of the calculations of the classic “duck” aircraft shows that in order to achieve the optimal load of the PGO, that is, approximately equal to the load on the wing, it is necessary to reduce the derivative of the classical, namely, the rigidly connected with the fuselage of the PGO, to a level of 40–70 percent. Ho, if this is not possible for the classical PGO, then it is possible to increase the derivative of the PPGO from zero to this value. For this, the FPGO is equipped with 1 elevator 4 steering wheel, which makes it possible to change the lift force of the FPGO with a change in the angle of attack of the aircraft, as a result of which its derivative increases and reaches the required value. In this case, the FPGO is involved in the formation of the stabilizing moment of the aircraft, namely, it compensates for the moment of pitch of the wing and thereby reduces the stabilizing moment to the required value. And even with the cruising congestion of the FPGO, equal to the congestion of the wing, conditions are provided for the aircraft's normal stability along the longitudinal channel.

Let us consider how a change in the level of lift occurs when the angle of attack of the oncoming air flow changes.

Let the angle of attack of the aircraft increase, then Servo 3 together with FPGO

1 are deflected relative to the aircraft counterclockwise. Given that the lever 7 is fixed by the pilot and remains stationary relative to the fuselage not shown in the drawing, and the length of the thrust 6 is unchanged, the elevator 4 is deflected clockwise, that is, down. The position of the FPGO after changing the angle of attack of the aircraft is shown in FIG. 3.

Since the actual angle of attack of the FPGO 1 with respect to the oncoming flow remained unchanged, and the elevator 4 deflected downward, the lifting force of the FPGO 1 increased. With a decrease in the angle of attack of the aircraft, the elevator 4 will deviate upward, and the lifting force of the FPGO will decrease.

By changing the length of the lever 5, it is possible to change the angle of the steering wheel

4 heights depending on the change in the angle of attack of the aircraft and thereby set the derivative of the FPGO with respect to the angle of attack of the aircraft. In addition, it can be influenced by the choice of steering wheel parameters 4 heights.

FPGO 1 output at large angles of attack by setting the servo wheel 3 in a certain position in a known manner in accordance with the release of the mechanization of the wing.

To control the pitch, the pilot deflects lever 7 clockwise or counterclockwise, for which purpose the draft 8, which is an element of the control system, serves. Thus, the pilot increases or decreases the lift force of the FPGO in order to change the pitch angle of the aircraft.

As a result, it can be concluded that the FPGO is equipped with a means for changing its lifting force in the form of a rudder 4, functionally dependent on a change in the angle between the base planes of the servo steering 3 and the aircraft in such a way as to increase the derivative of the lift coefficient for the bearing surface for the angle of attack of the aircraft.

Part of the FPGO 1 not occupied by the steering wheel 4 heights can be equipped with modern means of mechanization. In FIG. Figure 4 shows the FPGO equipped with a means for changing its lifting force in the form of an aggregate that changes the angle between the base planes of the FPGO and the aircraft by a proportional part of the change in the angle between the base planes of the servo steering and the aircraft.

FPGO 10 is pivotally connected to a fuselage not shown in the drawing along the geometric axis of rotation 00 perpendicular to the plane of symmetry of the aircraft. A rod 2 with a servo wheel 3 rigidly fixed on it is pivotally placed on the same axis

Rod 11 is articulated at some distance from the axis of OO ¹ with FPGO 10. In a diametrically located region relative to the axis of OO ¹ , rod 12 is pivotally connected. Other ends of rods 11 and 12 are pivotally connected to the ends of the shoulders of the two-arm rocker 13. The rocking chair 13 is pivotally placed on the fuselage (not shown in the drawing) along the axis OO ³ perpendicular to its plane of symmetry. The axis of OO ³ has the ability to move to the axis of OO ¹ or from it, while its position is fixed by rod 14, which is an element of the pitch control system. Arrow 9 marks the direction of the oncoming air flow.

Regardless of the pitch angle of the aircraft as a result of the combined action of aerodynamic forces on the FPGO 10 and on the servo wheel 3, the FPGO 10 is spontaneously set at a certain angle of attack to the direction of the oncoming flow indicated by arrow 9. At the same time, a lifting force arises on the FPGO 10. It compensates for the diving moment of a wing not shown in the drawing. Due to the lifting force arising at FPGO 10, the aircraft can be balanced with increased wing lift due to mechanization.

To increase from zero to the required value of the FPGO derivative, an aggregate is used, which in this case is represented by a mechanism consisting of elements 11, 12, and 13. Using this mechanism, the FPGO 10 is rotated not by the entire angle of the servo steering 3 relative to the aircraft when the direction of the oncoming flow changes , but only on its proportional part. If the proportion is half, then under the action of the upward flow, which leads to an increase in the angle of attack of the aircraft by 2 degrees, the actual angle of attack of the FPGO will increase by only 1 degree. The dashed lines indicate the position of FPGO 10 and servo-wheel 3 after changing the attack angle of the aircraft.

The change in the proportion and, thus, the determination of the value of the derivative, is easily carried out by selecting the corresponding distances of the hinged ends of the rods 11 and 12 to the axes OO ¹ and OO ³ .

To output the FPGO 10 to large angles of attack and to control the pitch, thrust 14 is used, with which the pilot changes the distance between the axes of OO ¹ and OO ³ . Thus, the pilot changes the angle between the FPGO 10 and the servo wheel 3, thereby increasing or decreasing the lifting force of the FPGO.

The invention allows you to change the derivative of PPGO, and hence the position of the focus of the aircraft during its flight, which is very easily achieved by performing the described mechanism in such a way that allows for the change in flight of at least one of the distances to the axis OO ¹ or OO ³ hinged the ends of the rods 11 and 12. For example, if you execute the rocking chair 13 with the possibility of its displacement relative to the axis of OO ³ , then you can change the ratio of its shoulders and thereby change the derivative of PPGO.

As a result, we can conclude that the PPGO is equipped with a means of changing its lifting force in the form of an aggregate represented by a mechanism of elements 11, 12 and 13, functionally dependent on a change in the angle between the base planes of the servo steering 3 and the aircraft in such a way as to increase the derivative with respect to the angle of attack of the aircraft lift for this bearing surface.

At FPGO 10, means can be used to increase their lifting force similar to modern wing ones.

To achieve the stability of the “weathervane duck”, it is possible not to increase the derivative of PPGO, but to reduce the derivative of the wing. For this, the mechanized wing is provided with a means of changing its lifting force in the form of a elevator, the change in the deflection angle of which is proportional to the change in the angle of deviation of the servo wheel relative to the aircraft reference plane.

This is accomplished by creating a connection, for example, using a hard wiring between the FPGO and the elevator. Moreover, for pitch control, the pilot changes the length of one of the wiring rods. To reduce the effort, the connection is not output to the wing elevator itself, but to the servo wheel located on it. Or they connect the FPGO with the control valve of the hydraulic system, which deflects the rudder.

When the FPGO is deflected counterclockwise as a result of an increase in the angle of attack of the aircraft, the wing elevator also deviates counterclockwise, i.e., upward and the lift force of the wing decreases, thereby offsetting the increase in the lift force of the wing as a result of the increase in the attack angle of the aircraft. With a decrease in the angle of attack, the elevator on the wing deviates downward and the lifting force of the wing increases, leveling the decrease in the angle of attack.

As a result, we can conclude that the wing is equipped with a means of changing its lift in the form of a elevator, which is functionally dependent on a change in the angle between the base planes of the servo-steering wheel and the aircraft in such a way as to reduce the derivative of the lift coefficient for the bearing surface for the angle of attack of the aircraft. Industrial applicability

The patented aircraft of the “weathervane duck” scheme significantly improves the characteristics of an aircraft of this class.

With the FPGO area of 15% of the wing area, it is guaranteed that it is possible to use the three-link slotted flap on the wing with full efficiency.

It makes it possible to reduce the wing area and horizontal tail of statically stable "ducks" by up to 40%.

Compared to the transport planes of the “normal” scheme, the total area of the wing and horizontal tail can be reduced by 15%.

The design of the proposed aircraft not less than 5% increases cruising aerodynamic quality compared to modern aircraft of the "normal" scheme, which reduces operating costs for fuel, increases the flight range of the aircraft and reduces environmental pressure on the environment during operation of the aircraft.

The author is sure that the proposed technical solution closes the eternal problem of the “duck” scheme in the use of wing mechanization, and further progress of civil aviation will advance in this direction.

Claims

CLAIM

Aircraft (LA) of the aerofoil "vane duck" aerodynamic scheme, containing bearing surfaces in the form of a mechanized wing and vane front horizontal tail unit (FPGO) equipped with at least one servo-wheel connected to the pitch control system, characterized in that at least at least one bearing surface is equipped with a means of changing its lifting force, functionally dependent on changes in the angle between the base planes of the servo-steering wheel and the aircraft in such a way as to increase the derivative with respect to the angle of attack of the aircraft coagulant lift for this bearing surface, if it is located in front of the aircraft's center of mass and reducing said derivative, if the surface is located behind the center of mass.

Aircraft according to claim 1, characterized in that the FPGO is equipped with a means of changing its lift, increasing its derivative with respect to the angle of attack of the aircraft of the lift coefficient, in the form of a elevator, the change in the angle of deviation of which is opposite and proportional to the change in the angle of deviation of the servo wheel relative to the base plane of the aircraft.

3. The aircraft according to claim 1, characterized in that the FPGO is equipped with a means of changing its lift, increasing its derivative with respect to the angle of attack of the aircraft, the lift coefficient, in the form of an aggregate that changes the angle between the base planes of the FPGO and the aircraft by a proportional part of the change in the angle between the base planes of a servo-wheel and aircraft.

4. Aircraft according to claim 1, characterized in that the mechanized wing is equipped with a means of changing its lift, reducing its derivative with respect to the angle of attack of the aircraft of the lift coefficient, in the form of a elevator, the change in the angle of deviation of which is proportional to the change in the angle of deviation of the servo wheel relative to the base plane of the aircraft .