RU2144885C1 - Maneuverable trainer multi-mission aircraft "yak- 130" - Google Patents

Abstract

FIELD: aeronautical engineering; aerodynamic configuration of aircraft. SUBSTANCE: aircraft includes fuselage with deceleration flap in upper portion, landing gear, two-jet engines, swept wing with front root ogival extension and vertical and horizontal tails. Root extension 9 is made with span of 0.15 to 0.18 of span of wing outer panel 8 and with chord of 0.4 to 0.5 of magnitude of local chord. Leading-edge step 12 is made at distance of 0.55 to 0.65 of magnitude of semispan and with chord of on less than 0.074 of magnitude of local chord of wing 8. Step 16 is made distance of 0.25 to 0.35 of span of outer panel of horizontal tail 15 magnitude of its chord is no less than 0.2 of magnitude of local chord with step 16 taken into account. EFFECT: improved maneuvering characteristics of aircraft at increased angles of attack and at high load ratio. 3 cl, 16 dwg

Description

The invention relates to aircraft, in particular to the aerodynamic layout of the aircraft, increasing its maneuverability, and can be used to create multi-purpose aircraft, which are subject to increased requirements for maneuverability at large angles of attack of at least 40 ^o , including the creation of training training aircraft.

 Improving the maneuverability of modern aircraft is achieved by an appropriate choice of geometric parameters while ensuring the lowest possible weight of the aircraft.

 The Hawk training aircraft of the British company British Aerospace (see Jane s "All the World's aircraft", 1994-1995, p. 435-438) is known from the state of the art. It contains a fuselage with a cockpit in the bow parts and side air intakes, chassis, power plant in the form of a turbojet engine, single-keel vertical and horizontal tail units.

The disadvantage of the design of the known aircraft is the possibility of its operation at angles of attack of not more than 25 ^o and as a result of this limitation of its maneuverability at elevated angles of attack.

 The closest technical solution, both in design and in tasks performed, selected as a prototype, is the manoeuvrable training aircraft Boeing F / A - 18 F of the American company Boeing / Northrop Crumman (see Flight International, January 20-26 1999, p. 38-49), comprising a fuselage with a cockpit in the bow and side air intakes, a chassis, a power plant in the form of two turbojet engines located in the fuselage, a swept wing with a front root influx of a lively shape, mechanization and deflectable socks with ledges front cro ki, dvuhkilevoe vertical and horizontal tail.

The main disadvantage of the known aircraft, selected as a prototype, is the relatively low weight perfection of its design, namely:
- the presence of two-keel vertical plumage increases its relative area, which increases the drag and the relative mass of the vertical plumage;
- the use of a root influx of increased scope and area to ensure the directional and lateral stability of the aircraft with a two-keel vertical tail at elevated angles of attack, which increases the relative mass of the wing;
- the removal of engine nozzles beyond the horizontal tail to prevent the jet stream from entering the aircraft structure increases the relative mass of the fuselage, in addition, due to the relatively small elongation of the wing, the prototype has a low aerodynamic quality.

 The low weight return of the structure and the low level of aerodynamic quality negatively affect the flight performance of a well-known aircraft.

The objective of the invention is the creation of a maneuverable aircraft with high aerodynamic characteristics in all flight modes and providing due to its aerodynamic layout high maneuverability at elevated angles of attack of at least 40 ^o at the highest possible weight perfection.

The technical results obtained from the use of this invention include the provision of longitudinal, directional and lateral stability of the aircraft in the entire operational range of angles of attack of at least 40 ^o with an increased level of aerodynamic quality while reducing its weight.

 The problem is solved, and the technical result is achieved by the fact that in a maneuverable aircraft containing the fuselage with the cockpit in the bow, a brake flap in its upper part and side air intakes, a landing gear, a power plant in the form of two turbojet engines located in the fuselage, a swept wing with a front root influx of a lively shape, mechanization and deflectable socks with ledges of the leading edge, vertical and horizontal plumage, according to the invention, the root influx of the wing is made with size at least 0.15 and no more than 0.18 wingspan span from the base of the influx and with a chord of at least 0.4 and no more than 0.5 of the local wing chord, and the ledge of the leading edge of the deflected wing tip is made at a distance of 0.55 - 0.65 magnitude of the wing console span from the base of the influx and with a chord of at least 0.075 of the local wing chord excluding the ledge, in addition, the vertical tail is single-tail, and the horizontal tail is equipped with a ledge along the leading edge at a distance of 0.25 - 0.35 console of horizontal plumage.

 The engines are located in the middle part of the fuselage so that their nozzles are in front of the horizontal tail, and the chord of the ledge of the leading edge of the horizontal tail is at least 0.2 of the local chord, taking into account the ledge.

The wing is provided with end aerodynamic surfaces made of at least 0.03 of the area of the base trapezoid of the wing and set at an angle of no more than 20 ^o to the vertical plane, and the chords of their bases are turned outward relative to the end chords of the wing by 2-5 ^o , and the aerodynamic twist also is 2-5 ^o .

In FIG. 1 shows a maneuverable aircraft with an explanation of geometric parameters, a combined view from above and below; in FIG. 2 - the same side view; in FIG. 3 - the same front view; in FIG. 4 shows the dependence of the coefficient of dynamic lateral stability of the aircraft at angles of attack of up to 40 ^o on the parameters of the root influx of the wing; in FIG. 5 - experimental results of visualization of the wing flow without a ledge and with a ledge; in FIG. 6 - the influence of the location of the ledge of the leading edge of the deflected nose of the wing on the longitudinal stability of the aircraft; in FIG. 7 - the influence of the size of the ledge of the leading edge of the toe on the longitudinal stability; in FIG. 8 - the influence of the location of the ledge horizontal plumage on longitudinal stability; in FIG. 9 - the influence of the parameters of the influx of the wing with the rational parameters of the steps on the degree of longitudinal stability of the overload at angles of attack up to 40 ^o ; in FIG. 10 - the results of flight tests, confirming the provision of longitudinal and transverse stability of the aircraft at angles of attack of up to 40 ^o ; in FIG. 11 - the nature of the flow of jet jets of the engines of the tail of the aircraft; in FIG. 12-15 - experimental dependences of the influence of the parameters of the terminal aerodynamic surfaces (CAP) on the relative aerodynamic quality of the aircraft; in FIG. 16 - results of flight tests on the effect of end aerodynamic surfaces on kilometer fuel consumption.

 A maneuverable aircraft contains a fuselage 1 with a cockpit 2 and side air intakes 3, a three-post landing gear with a nose wheel 4 and main bearings 5, a power plant in the form of two turbojet engines 6 located in the fuselage 1, and a brake flap 7 mounted on the fuselage 1. Airplane has a swept wing 8 with a front root influx 9 of a lively shape and mechanization made in the form of flaps 10 and deflectable socks 11 with ledges 12 of the leading edge. The aircraft contains a single-keel vertical tail 13 with a steering wheel 14 and horizontal tail 15 with a step 16 on the leading edge. Engines 6 are placed in the middle part of the fuselage 1 so that their nozzles are in front of the horizontal tail 15. The wing 8 is provided with end aerodynamic surfaces 17 (Fig. 1).

The root influx 9 is made with a span of l _n not less than 0.15 and not more than 0.18 span l _{kr of} the wing console 8 from the base of the influx 9 and with a chord b _n not less than 0.4 and not more than 0.5 of the local chord b _kr1 base trapezoid wing 8 without taking into account the ledge 12 of its leading edge.

The step 12 is made at a distance (l _mouth ) _cr = 0.55 - 0.65 of the wing span 8 from the base of the influx 9 and with the chord (b _mouth ) _{cr of} at least 0.075 magnitude of the local chord b _{cr2 of the} base trapezoid of wing 8 without taking into account step 12 its leading edge.

The step 16 of the horizontal tail 15 is made at a distance (l _mouth ) _r = 0.25-035 from the span l _{r of} the horizontal tail console 15, and the size of the chord is not less than 0.2 of the local chord b _{r of} horizontal plumage 15, taking into account ledge 16.

The end aerodynamic surfaces 17 are made with an area of at least 0.03 from the area of the base trapezoid of the wing 8 and are installed at an angle of no more than γ = 20 ^° to the vertical plane, and the chords of their bases are turned outward relative to the end chords of the wing at an angle φ _o = 2-5 ^° ,, and aerodynamic twist is also an angle φ _o = 2-5 ^° ..

 A maneuverable aircraft operates as follows.

где σ_β - коэффициент боковой динамической устойчивости самолета;
m $\genfrac{}{}{0ex}{}{\text{β}}{\text{y}}$ - производная коэффициента путевого момента по углу скольжения;
α - угол атаки;
J_y - момент инерции относительной вертикальной оси самолета;
J_x - момент инерции относительно горизонтальной оси самолета;
m $\genfrac{}{}{0ex}{}{\text{β}}{\text{x}}$ - производная коэффициента поперечного момента по углу скольжения.Takeoff and landing is similar to the prototype aircraft. In flight, with an increase in the angle of attack, due to the parameters of the root influx 9 of the wing 8, rational for the single-tail vertical tail 13, the lateral-track stability of the aircraft to attack angles of at least 40 ^{° is} ensured, which is explained by the positive interaction of the vortex structures of the root influx 9 with the vertical tail 13. Results tests (Fig. 4) models of the claimed maneuverable aircraft in a wind tunnel showed that the selected dimensions of the root influx 9 provide the required dynamic level for operation ESK lateral stability of the aircraft, namely:

where σ _β is the lateral dynamic stability coefficient of the aircraft;
m $\genfrac{}{}{0ex}{}{\text{β}}{\text{y}}$ - derivative of the coefficient of the travel moment with respect to the slip angle;
α is the angle of attack;
J _y is the moment of inertia of the relative vertical axis of the aircraft;
J _x - moment of inertia relative to the horizontal axis of the aircraft;
m $\genfrac{}{}{0ex}{}{\text{β}}{\text{x}}$ is the derivative of the transverse moment coefficient with respect to the slip angle.

 Due to the ledge 12 at the leading edge of the deflected toe 11, the separation zone of the air flow (Fig. 5) is shifted from the end of the wing 8 to its root part, which eliminates the appearance of a cabrioque moment and increases the longitudinal stability of the claimed aircraft. A similar effect provides a ledge 16 of the leading edge of the horizontal tail 15.

 In accordance with the results of experimental studies (Fig. 6-8), the rational parameters of the steps 12 and 16 provide the greatest improvement in the longitudinal stability of the aircraft. The influence of the root influx 9 of the wing 8 on the longitudinal stability of the aircraft is explained by the interaction of the vortex structures of the root influx 9 and the wing 8. A rational choice of the parameters of the influx 9 leads to a shift in the pressure center of the wing 8, which, with the selected parameters of the steps 12 and 16, provides the level of longitudinal degree required for operation sustainability.

где σ_n - степень продольной устойчивости самолета по перегрузке;
m_z ^Су - степень статической продольной устойчивости самолета;

коэффициент продольного демпфирования самолета;
ρ - плотность воздуха;
S - площадь крыла;
b - средняя аэродинамическая хорда крыла;
m - масса самолета.The results of experimental tests (Fig. 9) showed the optimality of the selected parameters of the root influx 9, ensuring compliance with the requirements for the level of longitudinal stability overload in the entire operational range of angles of attack, namely:

where σ _n is the degree of longitudinal stability of the aircraft overload;
m _z ^Su - the degree of static longitudinal stability of the aircraft;

coefficient of longitudinal damping of the aircraft;
ρ is the air density;
S is the wing area;
b - the average aerodynamic chord of the wing;
m is the mass of the aircraft.

 Flight tests (Fig. 10) confirmed the provision of longitudinal and transverse stability of the claimed aircraft in the entire operational range of angles of attack up to an angle of attack of at least 40.

 Moreover, the surface of the horizontal tail 15 at any angle of deviation up to the maximum due to its configuration, namely the presence of a step 16 of the leading edge with rational dimensions, is outside the jet jets of engines placed to reduce weight before the horizontal tail 15 (Fig. 11).

 Installed end aerodynamic surfaces 17 reduce the bevel of the air flow on the wing 8 induced by the end vortex, and also create additional suction force on their leading edges, which leads to a decrease in the inductive resistance of the wing 8 and to an increase in the aerodynamic quality of the aircraft.

(фиг. 12-15).Experimental studies have confirmed the optimality of the selection of the parameters of the end aerodynamic surfaces 17 of the wing 8, providing the highest relative aerodynamic quality

(Fig. 12-15).

In addition, the results of flight tests (Fig. 16) confirm the positive effect of the end aerodynamic surfaces 17 on the kilometer fuel consumption q _kn , i.e. on its aerodynamic quality.

 The proposed design of a maneuverable aircraft has high aerodynamic characteristics in all flight modes, provides due to its aerodynamic layout improved maneuverability at elevated angles of attack of at least 40 and has an increased level of aerodynamic quality at the highest possible weight perfection, namely, in comparison with the known prototype aircraft the relative area of vertical plumage is reduced by 25-30% and its relative mass is not less than 20%. In addition, the area and relative mass of the root wing influx were reduced by at least 30% and the mass of the fuselage tail was reduced by at least 10% of the total mass of the fuselage.

 Technical results obtained from the use of this invention are confirmed by flight tests of the Yak-130 aircraft.

Claims (3)

 1. A maneuverable aircraft containing a fuselage with a cockpit in the bow, a brake flap in its upper part and side air intakes, a landing gear, a power plant in the form of two turbojet engines located in the fuselage, a swept wing with a front root influx of a lively shape, mechanization and deflectable socks with ledges of the leading edge, vertical and horizontal plumage, characterized in that the root influx of the wing is made with a span of not less than 0.15 and not more than 0.18 of the span of the wing console from the base of the influx and with x a radius of not less than 0.4 and not more than 0.5 of the local wing chord, and the ledge of the leading edge of the deflected wing tip is located at a distance of 0.55 - 0.65 of the magnitude of the wing console span from the base of the influx and with a chord of at least 0.075 of the local chord wings without a ledge, the vertical tail is made single-winged, and the horizontal tail is equipped with a ledge along the leading edge at a distance of 0.25 - 0.35 of the span of the horizontal tail.  2. The maneuverable aircraft according to claim 1, characterized in that the engines are installed in the middle part of the fuselage so that their nozzles are placed in front of the horizontal tail, and the chord of the ledge of the leading edge of the horizontal tail is at least 0.2 of the local chord, taking into account the ledge. 3. A maneuverable aircraft according to claims 1 and 2, characterized in that the wing is provided with end aerodynamic surfaces made with an area of at least 0.03 from the area of the base trapezoid of the wing and set at an angle of no more than 20 ^o to the vertical plane, and the chords of their bases are rotated outward relative to the terminal chords of the wing by 2 - 5 ^o , and their aerodynamic twist is also 2 - 5 ^o .

Images