Low-speed longitudinal stability-increasing control surface of plane-tail-free aircraft and aircraft with sameTechnical Field
The application belongs to the field of design of control surfaces of aircraft, and particularly relates to a low-speed longitudinal stability augmentation control surface of a plane tail-free aircraft and an aircraft with the same.
Background
The aircraft without the horizontal tails has the characteristic of relatively common low-speed longitudinal moment characteristic, namely, before the aircraft reaches a stall attack angle (namely, a lift coefficient inflection point) corresponding to the maximum lift coefficient, the derivative of the longitudinal moment coefficient on the attack angle gradually becomes larger, the longitudinal moment coefficient is converted from a negative value to a positive value, namely, the longitudinal moment coefficient firstly presents the inflection point, then the lift coefficient continues to rise to present the inflection point, the longitudinal stability of the aircraft gradually becomes smaller, the aircraft becomes neutral stable and unstable from the static stability, if an active flight control system is not adopted, the aircraft cannot normally and safely fly after the longitudinal moment coefficient inflection point and before the lift coefficient inflection point, and a quite large part of lift coefficient and attack angle of the aircraft cannot be used, so that the flight performance of the aircraft is difficult to reach the expectations.
At present, the low-speed longitudinal stability augmentation of the plane without the horizontal tail mainly adopts the soft stability augmentation of an active flight control system, and the soft stability augmentation of the active flight control system changes the dynamics characteristic of the plane body by utilizing closed-loop state feedback, thereby realizing the adjustment of the modal characteristic of the plane. The soft stability augmentation design of the active control system improves the stability characteristics of the plane without the horizontal tail to a certain extent, so that the relative safe and reliable flight of the plane without the horizontal tail is possible, but the active control stability augmentation design often depends on a sensor, flight control software, an actuating system, a control surface aliquoting system, the complexity of the system is greatly increased as a whole, and the reliability is reduced. Meanwhile, the active control stability augmentation design is often constrained by the conditions of control surface deflection speed, rudder effectiveness, deflection authority and the like, generally speaking, only the pneumatic characteristics of the whole aircraft are repaired, the stability characteristics of the aircraft are not allowed to be changed in a large range, and the excessive reduction of the operation characteristics is prevented.
Compared with the soft stability augmentation adopting an active flight control system, the stability augmentation method only depends on the reliability and the safety of the hard stability augmentation of the control surface of the airplane body, and when the hard stability augmentation cannot realize the required stability, a method of combining the hard stability augmentation and the soft stability augmentation or a method of completely soft stability augmentation is adopted. Since the existence of the plane tail free aircraft, research has been conducted on how to solve the stability problem. Related research and research on "hard" stability augmentation of a plane without a horizontal tail are always carried out, but no implementation way and method of the "hard" stability augmentation are found yet, and the main reasons are that the "hard" stability augmentation has a plurality of constraints and great difficulty.
Because the stranding-free aircraft has no stranding, longitudinal trimming mainly depends on control surfaces such as simple flaps, ailerons, simple flap ailerons and the like on the trailing edge of wings, compared with the aircraft with conventional layout, the control surfaces are very close to the center of gravity of the aircraft, so that the longitudinal trimming capability is smaller, the lift loss caused by trimming is larger, and in order to realize the comprehensive performances of stealth, weight control, simple mechanism and the like of the stranding-free aircraft, the hard stability augmentation measures are required to be adopted, and the hard stability augmentation measures are required to have small low head moment increment, proper longitudinal stability increment, small lift loss, the number of mechanisms is not increased or increased as much as possible, the mechanism control is simple, the stealth influence is small, the weight increment is small and the like.
Disclosure of Invention
In order to solve at least one of the technical problems, the application designs a low-speed longitudinal stability augmentation control surface of a plane without a horizontal tail, and the low-speed longitudinal static stability of the plane is improved through a hard stability augmentation measure.
The first aspect of the application provides a low-speed longitudinal stability augmentation control surface of a plane without a horizontal tail, which mainly comprises the following components:
The main wing is provided with an upper wing surface and a lower wing surface which are supported by a rear wing spar of the main wing, and the rear end of the main wing is provided with an arc-shaped groove for connecting the upper wing surface and the lower wing surface;
the front end of the flap is provided with an arc-shaped surface, and the arc-shaped surface rotates in the arc-shaped groove when the flap is controlled to deflect relative to the main wing;
the rear end of the upper cover plate is lapped on the upper side of the front end arc surface of the flap aileron, and the front end of the upper cover plate is hinged on the upper wing surface of the main wing;
The lower cover plate comprises a front lower cover plate hinged with the lower wing surface of the main wing and a rear lower cover plate fixed with the lower side of the front end arc-shaped surface of the flap aileron, and the front lower cover plate is mutually overlapped with the other end of the rear lower cover plate;
And the actuating device is used for driving the upper cover plate to rotate upwards around the hinge point of the upper cover plate and the main wing so as to form a first channel between the upper cover plate and the flap aileron, and simultaneously driving the front lower cover plate to rotate upwards around the hinge point of the front lower cover plate and the main wing so as to form a second channel between the front lower cover plate and the flap aileron, wherein the first channel and the second channel form an air flow guiding the lower surface of the main wing to flow to the upper surface of the flap aileron.
Preferably, the flap is capable of rotating around a flap hinge point, the flap hinge point of the flap is located at a first set distance behind the main wing rear spar, and the first set distance is 9% -11% of the local chord length of the wing.
Preferably, the first set distance is 10% of the local chord length of the wing.
Preferably, the upper cover plate is hinged at a second set distance from the rear part of the rear wing spar of the main wing through an upper cover plate hinge point, the second set distance is 3.5% -4.5% of the local chord length of the wing, the front lower cover plate is hinged at the position, close to the rear wing spar, of the main wing through a front lower cover plate hinge point, and the length ratio of the front lower cover plate to the rear lower cover plate is 8:2.
Preferably, when the upper cover plate rotates upwards to the maximum angle around the hinging point of the upper cover plate and the main wing, the distance between the rear end of the upper cover plate and the upper end surface of the flap aileron is 0.5% -1.5% of the local chord length of the wing, and the front lower cover plate rotates upwards to the position where the rear end of the front lower cover plate contacts the upper cover plate around the hinging point of the front lower cover plate and the main wing.
The second aspect of the application provides an aircraft with a low-speed longitudinal stability augmentation control surface of a tailless aircraft, the aircraft comprises a left wing main body and a right wing main body, the rear end of the left wing main body is provided with a left outer flap and a left inner flap, the rear end of the right wing main body is provided with a right outer flap and a right inner flap, wherein at least one of the left outer flap, the left inner flap, the right outer flap and the right inner flap is provided with the low-speed longitudinal stability augmentation control surface of the tailless aircraft.
Preferably, the upper cover plate and the front lower cover plate are controlled to deflect upwards when the aircraft is in a take-off or landing state, the first passage and the second passage are opened, and the upper cover plate and the front lower cover plate are not deflected when the aircraft is in a cruising state.
The application can change the static stability of the aircraft, realize the improvement of the longitudinal static stability, effectively reduce the design complexity of the flight control system, reduce the rudder effect requirement of the aircraft, increase the capability of changing after the tail-free aircraft stalls, and integrally improve the flight reliability and safety of the aircraft.
Drawings
FIG. 1 is a schematic view of a stowable upper and lower deck of a preferred embodiment of a low speed longitudinal stability augmentation control surface of a tailless aircraft of the present application.
FIG. 2 is a schematic view of an upper and lower deck opening condition of a preferred embodiment of a low speed longitudinal stability augmentation control surface of a tailless aircraft of the present application.
Fig. 3 is a schematic view of a strapless aircraft structure according to a preferred embodiment of the present application.
The device comprises a 1-plane without a horizontal tail, a 2-air inlet, a 3-air outlet, a 41-left resistance rudder, a 42-right resistance rudder, a 51-left outer flap aileron, a 52-right outer flap aileron, a 61-left inner flap aileron and a 62-right inner flap aileron;
7-main wing, 8-main wing rear spar, 9-upper cover plate, 91-upper cover plate hinge point, 10-front lower cover plate, 101-front lower cover plate hinge point, 11-rear lower cover plate, 12-flap aileron and 121-flap aileron hinge point.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application become more apparent, the technical solutions in the embodiments of the present application will be described in more detail with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of the application. The embodiments described below by referring to the drawings are exemplary and intended to illustrate the present application and should not be construed as limiting the application. All other embodiments, based on the embodiments of the application, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the application. Embodiments of the present application will be described in detail below with reference to the accompanying drawings.
The first aspect of the present application provides a low-speed longitudinal stability augmentation control surface of a tailless aircraft, as shown in fig. 1 and 2, mainly comprising:
the main wing 7 is provided with an upper wing surface and a lower wing surface which are supported by a main wing rear spar 8, and the rear end of the main wing 7 is provided with an arc-shaped groove for connecting the upper wing surface and the lower wing surface;
A flap 12, the front end of which is provided with an arcuate surface which rotates within the arcuate slot when the flap 12 is controlled to deflect relative to the main wing 7;
an upper cover plate 9, the rear end of which is lapped on the upper side of the arc-shaped surface of the front end of the flap 12, and the front end of which is hinged on the upper wing surface of the main wing 7;
The lower cover plate comprises a front lower cover plate 10 hinged with the lower wing surface of the main wing 7 and a rear lower cover plate 11 fixed with the lower side of the front end arc surface of the flap aileron 12, wherein the front lower cover plate 10 is mutually overlapped with the other end of the rear lower cover plate 11;
And the actuating device is used for driving the upper cover plate 9 to rotate upwards around the hinge point of the upper cover plate 9 and the main wing 7 so as to form a first channel between the upper cover plate 9 and the flap 12, and simultaneously is used for driving the front lower cover plate 10 to rotate upwards around the hinge point of the front lower cover plate 10 and the main wing 7 so as to form a second channel between the front lower cover plate 10 and the flap 12, and the first channel and the second channel form a channel for guiding airflow on the lower surface of the main wing 7 to flow to the upper surface of the flap 12.
According to the technical scheme, the simple flap aileron of the plane without the horizontal tail and the upper cover plate and lower cover plate combination at the front part of the plane are designed, the upper cover plate and the lower cover plate combination deflect upwards at different angles, an airflow channel is formed between the simple flap aileron and the upper cover plate under the condition that the simple flap aileron does not deflect, as shown in figure 2, the flow energy of the upper surface of the rear edge of the wing is increased, the flow separation of the upper surface of the rear edge of the wing is eliminated or slowed down before the attack angle of stall, and the low-speed longitudinal static stability of the plane is improved.
In some alternative embodiments, the flap 12 is rotatable about a flap hinge point 121, the flap hinge point 121 of the flap 12 being located a first set distance behind the main wing rear spar 8, the first set distance being 9% -11% of the local chord of the wing.
In some alternative embodiments, the first set distance is 10% of the local chord length of the wing.
In some alternative embodiments, the upper cover plate 9 is hinged at a second set distance behind the main wing rear spar 8 through an upper cover plate hinge point 91, the second set distance is 3.5% -4.5% of the local chord length of the wing, the front lower cover plate 10 is hinged at a position of the main wing 7 near the main wing rear spar 8 through a front lower cover plate hinge point 101, and the length ratio of the front lower cover plate 10 to the rear lower cover plate 11 is 8:2.
In this example, it is considered that the flap 12 is designed at a chord length of about 10% behind the wing rear spar 8, and an upper cover plate having a chord length of about 6% and a front lower cover plate having a chord length of about 8% and a rear lower cover plate having a chord length of about 2% are designed between the wing rear spar 8 and the flap 12 on the side close to the flap 12.
In some alternative embodiments, when the upper cover plate 9 rotates up to the maximum angle around the hinge point of the upper cover plate and the main wing 7, the distance between the rear end of the upper cover plate 9 and the upper end surface of the flap aileron 12 is 0.5% -1.5% of the local chord length of the wing, and the front lower cover plate 10 rotates up to the point that the rear end of the front lower cover plate 10 contacts the upper cover plate 9 around the hinge point of the front lower cover plate and the main wing 7.
The application utilizes the actuating device, the upper cover plate can deflect upwards around the hinge point at the front end of the upper cover plate, the front lower cover plate can deflect upwards around the hinge point at the front end of the coil until the front lower cover plate contacts with the upper cover plate, the front lower cover plate and the upper cover plate can form an airflow channel with the flap aileron after being deflected, and the rear lower cover plate is fixed on the rear beam of the wing through the supporting structure. Typically, the flap is not deflected, and if desired for handling and trimming, the flap may be deflected up or down as desired.
The simple flap aileron and the upper cover plate and lower cover plate combined design at the front part of the simple flap aileron can fully utilize the original simple flap aileron of an airplane and the upper cover plate and lower cover plate mechanism at the front part of the simple flap aileron to realize the synchronization of a longitudinal moment inflection point and a lift coefficient inflection point and the improvement of longitudinal static stability, and the mechanism is simple and convenient to control, does not influence the original function of the simple flap aileron, has little influence on the lift coefficient, weight and stealth performance of the airplane, has small increment of low-head moment, has proper increment of longitudinal static stability, fully utilizes the lift coefficient and attack angle of the airplane, and expands or improves the low-speed flight performance of the airplane.
Compared with the soft stability enhancement of an active flight control system, the invention has the advantages that the control surface design is adopted, the control surface active control occupied by specific authority and rudderness is not needed, the static stability of the aircraft can be changed only by carrying out preset deflection on the control surface, the improvement of the longitudinal static stability characteristic is realized, the design complexity of the flight control system is effectively reduced, the rudder efficiency requirement of the aircraft is reduced, the capability of improving the aircraft after the zero-tail aircraft stalls is increased, and the flight reliability and safety of the aircraft are integrally improved.
The second aspect of the present application provides an aircraft with a low-speed longitudinal stability augmentation control surface of a tailless aircraft, as shown in fig. 3, the aircraft is a tailless aircraft 1, the front part of the aircraft is provided with an air inlet 2, the rear part of the aircraft is provided with an air outlet 3, the aircraft further comprises a left wing main body and a right wing main body, the rear end of the left wing main body is provided with a left drag rudder 41, a left outer flap aileron 51 and a left inner flap aileron 61, and the rear end of the right wing main body is provided with a right drag rudder 42, a right outer flap aileron 52 and a right inner flap aileron 62, and the low-speed longitudinal stability augmentation control surface of the tailless aircraft is provided with at least one of the left outer flap aileron 51, the left inner flap 61, the right outer flap aileron 52 and the right inner flap aileron 62.
In some alternative embodiments, the upper cover plate 9 and the front lower cover plate 10 are controlled to deflect upwards when the aircraft is in a take-off or landing state, the first passage and the second passage are opened in the manner of fig. 2, and the upper cover plate 9 and the front lower cover plate 10 are not deflected when the aircraft is in a cruising state, and are retracted in the manner of fig. 1.
The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present application should be included in the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.