CN105109669B - Aircraft recovery spin improving device - Google Patents

Abstract

The invention relates to an aircraft spin recovery improving device, belongs to the aircraft industry which comprises the aircraft controllability and the stability field, and aims at improving the use safety and reaching the necessary quality of the training aircraft. The plan of the device shows that the device comprises two horizontal tail strakes in lifting surface forms. The two lifting surfaces are symmetrically arranged on the tail part of the aircraft relative to the longitudinal symmetrical surface of the aircraft and are connected with a horizontal tail near the wing root chord of the horizontal tail. In a range of 1.1-1.5b of each lifting surface along the aircraft body length, the maximum width can be reached between each lifting surface and the connection part, and the maximum width is in the range of 0.1-0.15b, wherein b is the wing root chord of the horizontal tail. The swept-back angle from the middle of each lifting surface to the horizontal tail is 90 degrees to 115 degrees. When any of the present recovery method is operated, the device provided by the invention enables the aircraft to recover the spin even when all of the control mechanism is deflected to the middle position, so as to improve the aircraft operational safety substantially.

Description

Aircraft changes tailspin improves device

Technical field

The invention belongs to aviation field, the invention of recommendation is improved for making trainer aircraft change tailspin, and can train Aircraft is changed tailspin with different methods by pilot, and in particular to aircraft changes tailspin improves device.

Background technology

Search out the scientific and technological scheme for improving that aircraft changes characteristic from tailspin state it may first have to which aircraft is ensured uses peace Quan Xing.It is well known that according to world's aviation accident statistical data, nearly 50% aircraft accident and accident are all in these states Lower generation (《Airplane aerodynamic under High Angle of Attack. books inventory》, Russian central fluid dynamic study institute joint sci-tech publication Society, 1990；《General Aviation. to the suggestion of designer》, В. and Г. М и к e л а д з e, Russian central fluid dynamic study institute go out Version, page 2001,213).

In addition, Tail chain is changed with trainer aircraft improves that problem is relevant also includes：

On the one hand, it can be received the relatively small number of pilot's use of training；

On the other hand, on this aircraft, usually train pilot, it is necessary to can demonstrate out and aircraft is changed into tailspin All Existing methods (《General Aviation. to the suggestion of designer》, В. and Г. М и к e л а д з e, Russian central fluid power grind Study carefully institute to publish, page 2001,276；64 С of Russian Federation patent № 2297364, М П К В 5/08,2007； CN201694385, М П К B64C17/00；B64C3/00,2011；5,575,442, М П К B63H1/18 of United States Patent (USP)； B64C21/00,1996).

So-called Λ shapes wing edge strip device as you know, it with fuselage connection position be equipped with sweepforward edge (《In Russia Centre fluid dynamic research institute academic journal》, Х Х VII volumes, the № 1-2 phases, 1996, В o ж д а e в Е. С., Г o л o в к и н В. А., Г o л o в к и н М. and А., Д o л ж e н к o Н. and Н .).Installing this Λ shapes edge strip can cause afterbody The whirlpool beam formed with wing edge strip itself is separated.Therefore, occur below the leeward whirlpool beam of edge strip along the leeward outer wing extension of wing During sideslip, less negative pressure can be formed, and forms the less lift for causing stable rolling moment occur, so as to improve aircraft Stalling characteristics.

The defect of this device is that it cannot be used for not having on the aircraft of wing edge strip, and not can determine that it to changing The impact of Tail chain.

Immediate in familiar technical scheme is a kind of device with edge strip, and the profile of edge strip is two triangle lift Face, it is installed in afterbody, symmetrical relative to the longitudinally asymmetric face of aircraft, and (network address is docked with horizontal tail near wing root wing chord： http://www.airwar.ru/enc/other/stucano.html and www.embraerdefensesystems.com/ english/content/combat/tucano_three_view.asp)。

This edge strip is installed before horizontal tail, as the result of the test carried out in vertical wind tunnel, will be caused：

- extra underriding torque occurs under High Angle of Attack；

- increase damping due to rotation；

- due to above-mentioned two factors, aircraft can by 70 ° of angle of attack α ≈ when the horizontal tail rotation state that occurs enter steep tail Rotation state, the angle of attack at this moment is 50 ° of α ≈, and speed can be lower.

So, although aircraft changes Tail chain and is improved, but can only using it is so-called reinforcement drive manner it is (this In the case of be initially the completely anti-tailspin deflection of aileron and rudder, then cross 0.5 and enclose --- rudder is fully towards under) change.This Individual device and device similar therewith all it cannot be guaranteed that tailspin state is changed by aircraft for additive method, including all behaviour Vertical mechanism deflects into neutral and all operating mechanisms simultaneously, and (rudder and aileron are while deflect into neutral position in the correct order Put, cross 0.5～1 circle after --- elevator deflects into neutral position) situation.

The content of the invention

The task and technological achievement of the present invention is to improve device to develop a kind of aircraft and changing tailspin, can improve aircraft Tail chain and change Tail chain, it is ensured that the safety in utilization of aircraft can be improved, this point to trainer aircraft particular importance, Generally, pilot will go to school in such aircraft can the method that changes of all tailspins.

Aircraft changes tailspin improves device, by this aircraft change tailspin improve device be obtained task solution and Technological achievement.This device includes the edge strip that profile is two lifting surfaces, and they are arranged on afterbody, relative to aircraft longitudinal direction The plane of symmetry is symmetrical, and is connected with horizontal tail near horizontal tail wing root wing chord.The length of each lifting surface along fuselage length direction is 1.1～1.5b, and be 0.1～0.15b with the Breadth Maximum of horizontal tail junction, wherein b are horizontal tail wing root wing chord, each lifting surface Mid-length to horizontal tail angle of sweep be 90 °～115 °.

This geometric shape of device and position are the trainer aircraft dynamic similarity model tailspin shapes carried out in vertical wind tunnel On the basis of experimental study under state, and just install what is determined after impact of this device to model characteristics has carried out calculating assessment. During super high-angle-of-attack flight, the fuselage cross-section that edge strip position is installed near horizontal tail can form extra normal force, this normal force meeting Cause extra underriding torque occur.Thus, compared with initial scheme, the tailspin of model is appeared under the less angle of attack. In addition, when tailspin state drag rotates, in windward side, dock formed with fuselage by the lifting surface positioned at windward side Extra air flow resistance can be formed in dihedral angle, rotational resistance increase is thus resulted in, that is, damping increases, and model can be with Less angular velocity rotation.Lifting surface shape, size and sweepback from the composition horizontal tail edge strip unlike prototype, selected Angle, causes the vortex formed in lifting surface lateral edges windward not leave vertical fin, but directly in its vicinity and stream is washed in formation, this The extra damping that stream can promote to produce by vertical fin is washed a bit, so as to also reduce further angular velocity of rotation.

The geometric shape formed by the device of recommendation to can guarantee that and form enough normal force, and volume on edge strip near horizontal tail Outer damping due to rotation.This damping due to rotation is depended on the lifting surface positioned at windward side and is docked with fuselage in formed dihedral angle The air flow resistance of formation, but depending on the vortex formed on the lifting surface lateral edges, the formation of vortex is mutual well with vertical fin Effect.

Description of the drawings

Fig. 1,2 give various configuration schemes and get off the plane and change tailspin and improve the full view of device.

Fig. 3 gives the formation mechanism of the extra underriding torque for causing angle of attack reduction in tailspin, and damping rotation is additionally Torque formation mechanism.

Fig. 4 gives the vortex formed in lifting surface lateral edges windward and is formed, and it is interacted well with vertical fin, and shape Into damping additional moment due to rotation.

What Fig. 5 was given is that the trainer aircraft free flight dynamic similarity model with recommendation apparatus is driven by reinforcement in vertical wind tunnel The method of sailing changes the result of the test of tailspin, and wherein t is the time, and ψ is the model rotation angle of relative vertical line；α is the angle of attack；β is sideslip Angle；δ is operating mechanism deflection angle.Here additionally use following abbreviation：р. н .-rudder, р. в .-elevator, э л e р o н (п р .)-show that starboard aileron is deflected.

What Fig. 6 was given is that same model deflects into result of the test when neutral position changes tailspin in all operating mechanisms.

Fig. 7 is the model test result in initial scheme, without the device recommended, is driven by reinforcement when changing tailspin Method.

What Fig. 8 was given is the model test result with prototype plant, by strengthening drive manner when changing tailspin.

Fig. 9 gives the model test result with prototype plant, and all operating mechanisms are deflected into neutrality when changing tailspin Position.

Specific embodiment

Aircraft changes tailspin improves device (Fig. 1) including the edge strip near horizontal tail, and plane graph profile is two 1 Hes of lifting surface 2, it is installed in afterbody 3, symmetrical relative to the longitudinally asymmetric face 4 of aircraft, it is connected with horizontal tail 5 near horizontal tail wing root wing chord.Edge The length of each lifting surface of fuselage length direction is 1.1～1.5b, and the Breadth Maximum with horizontal tail link position each lifting surface is 0.1～0.15b, wherein b are horizontal tail wing root wing chord, and the angle of sweep of mid-length to horizontal tail is 90 °～115 °.

Now research aircraft changes tailspin improves the working condition of device (Fig. 1,2).Its saddlebag is containing as follows.Aircraft is big When the subcritical angle of attack, tailspin state flight, the fuselage cross-section of institute recommendation apparatus, appearing above in fuselage and device itself is being installed Air flow resistance is additionally pressurized, therefore, extra normal force Δ N (Fig. 3) is formed in longitudinally asymmetric face, the normal force promotes to form volume Outer underriding torque Δ Mz simultaneously reduces the aircraft α angles of attack.Under tailspin state, i.e. when there is angular velocity of rotation ω, when, form total speed Degree vector W's streams, linear speed ω × r × sin α that the velocity is equal to speed V and is caused by the rotation of model aircraft angle Vector, wherein r is the current distance in-А sections from model center of gravity to А.In a word, in dihedral angle (lifting surface and machine windward The docking of body) extra air flow resistance is formed, and form power P1 and damping turning moment M д 1 (Fig. 3).Therefore, the motion of model There is less angular velocity.Can lead from size and angle of sweep selected by the lifting surface of horizontal tail adnexa edge strip unlike prototype, is formed Cause the vortex occurred in lifting surface lateral edges windward Γ to be formed without departing from vertical fin (Fig. 4), but directly pass through in its vicinity.It is this Vortex formation can produce induced velocity υ i, and these induced velocities can form power P2 and extra damping turning moment M д in vertical fin 2, and correspondingly reduce angular velocity of rotation ω.The physical dimension formed by the device recommended can guarantee that because installing the device and Described enough good effects above generation, therefore, mean angle of attack α of the model in free flight=f (t) (Fig. 5,6) is α 45 ° of ≈, rotational frequency ω=6.51/ second, i.e.,(Fig. 5 and Fig. 6, ψ=f (t)).This can just use reinforcement method In about 0.5 circle trainer aircraft is made to change tailspin, that is to say, that after the anti-tailspin action of all rudder faces, 180 ° of ψ (t) ≈, and In enclosing about 2.5 after all rudder face actions (Fig. 6), just can trainer aircraft even with all operating mechanisms are deflected into neutral position Change tailspin, so finally can guarantee that the substantive raising of aircraft utilization safety.In order to be compared, give does not have Fig. 7 Archetype result of the test during institute's recommendation apparatus.As can be seen that mean angle of attack of the archetype in tailspin is 71 ° of α ≈, rotation It is ω=101/ second to turn frequency, while or even in the so-called reinforcement changing ways of operating mechanism sequence of movement correspondence in about 5 circles Interior model does not change tailspin yet (angle of attack is not lowered to acceptable about 15～20 °).Fig. 8, Fig. 9 are in order to enter with Fig. 5, Fig. 6 Row compares, it is shown that the result of the test with prototype plant.As can be seen that the tailspin of model occurs in 50 ° of mean angle of attack α ≈, rotation Turn frequency for ω=6.81/ second.These parameter values are substantially less better than band institute recommendation apparatus model.Model with prototype plant Tailspin (Fig. 8) can be changed with reinforcement method, but, as seeing in Fig. 9, model is in each rudder face action to neutral position Postpone.Test of many times shows that the model with prototype plant is only adopted with reinforcement drive manner and changes tailspin, This is inadequate for the trainer aircraft for training pilot.

Have been proven that installation recommended in the test of vertical wind tunnel by mathematical modelling and dynamic similarity free flight model Device and the effect that reaches is good.

Claims (1)

1. a kind of aircraft changes tailspin improves device, it comprising two lifting surface forms edge strip, the two lifting surfaces relative to The longitudinally asymmetric face of aircraft is symmetrically mounted on afterbody and is directly docked with horizontal tail being close near horizontal tail wing root wing chord, its feature Be, each the lifting surface length along fuselage length in the range of 1.1～1.5b, and each lifting surface at which docking with horizontal tail Place reaches Breadth Maximum, the Breadth Maximum in the range of 0.1～0.15b, wherein, b is horizontal tail wing root wing chord, and each lifting surface Mid-length to horizontal tail angle of sweep be 90 °～115 °.