CN115946843B - A method for adjusting the jamming of aircraft empennage and elevator - Google Patents

Abstract

The invention discloses an aircraft tail wing and elevator blocking adjustment method, which comprises an original horizontal tail wing, an original vertical tail wing and a standby horizontal tail wing arranged on the vertical tail wing; the standby horizontal tail fin is rotatably arranged on the original vertical tail fin through a rotating shaft; the horizontal wings of the spare part are arranged at the top end of the original vertical tail wing when being unfolded and are perpendicular to the original vertical tail wing. The invention has the advantages that under the condition of not influencing the normal operation of the original tail wing, the load of the aircraft is basically unchanged, but the probability of flight accidents caused by the fault of the tail wing can be effectively reduced, and the burden of pilots under emergency conditions is reduced.

Description

A method for adjusting the jamming of aircraft empennage and elevator

technical field

The invention relates to the field of aviation technology, in particular to an aircraft empennage and elevator jamming adjustment method.

Background technique

With the advancement of science and technology and the rapid development of transportation methods in human society, airplanes have become one of the mainstream means of transportation. As a device installed at the tail of the aircraft, the empennage can maintain the pitch stability and direction balance of the aircraft, and make the aircraft have pitch and direction stability and manoeuvrability. At present, there are many design schemes for aircraft empennage, but most of them include horizontal stabilizer, elevator, vertical stabilizer and rudder in structural composition.

The issue of flight safety, especially in the field of civil aviation, has always been paid attention to. The failure of the horizontal tail and the decrease of pitch stability lead to the loss of control of the aircraft is also one of the important research topics. The types of flight accidents are divided into controllable flight, loss of control, runway safety, ground safety, operation failure, aircraft fire, etc. The four types of flight accidents of out-of-control, runway safety, controllable flight and operation failure are high-risk accidents, and the number of deaths caused by out-of-control flight accidents is on the rise, which is higher than that of controllable flight and runway safety. It has become the type of civil aviation flight accident with the largest number of casualties. Tail failure is one of the common factors that cause aircraft out of control, and the damage caused by elevator jamming is huge. At present, when the elevator is jammed up or down, the pilot's trimming, push rod and other operations can also realize the pitching operation of the aircraft; when the elevator is completely jammed, according to the FAA "Aircraft Flight Manual", it means that the elevator is completely out of control. Then, the combined operation of throttle stick and flaps can still provide relatively limited pitch control, which depends on the design difference of each aircraft. Obviously, this situation is very challenging, there are great requirements on the pilot's driving level, and the possibility of failure is very large.

Therefore, it is urgent to start from the design of the aircraft empennage, and provide an emergency measure for the elevator jamming problem of the horizontal empennage from the source, so as to effectively reduce the possibility of aircraft out-of-control accidents caused by elevator failure.

Contents of the invention

The purpose of the present invention is to provide a method for adjusting the jamming of aircraft empennage and elevator, to solve the problems in the above-mentioned prior art, and to realize

To achieve the above object, the present invention provides the following scheme: the invention provides a kind of aircraft empennage, comprising: former horizontal empennage, former vertical empennage and the standby horizontal empennage that is installed on the described former vertical empennage; Described spare horizontal empennage passes rotating shaft Rotatingly installed on the original vertical tail; the spare horizontal wing is placed on the top of the original vertical tail when unfolded, and is vertically arranged with the original vertical tail.

The original horizontal stabilizer includes the original elevator and the original horizontal stabilizer; the upward jamming angle of the original elevator is 30°, and the downward jamming angle is 15°.

The original vertical stabilizer includes a rudder and the original vertical stabilizer; the two side walls of the original vertical stabilizer are inwardly provided with grooves for installing the spare horizontal stabilizer.

The spare horizontal stabilizer includes a spare elevator and a spare horizontal stabilizer; the spare horizontal stabilizer and the spare elevator are both provided with two pieces, and are respectively installed in the two grooves of the original vertical stabilizer through the rotation of the rotating shaft. .

The maximum upward deflection angle of the spare elevator is 30°, and the maximum downward deflection angle is 15°.

A method for adjusting elevator jamming, comprising the following steps:

When the original elevator is stuck, the spare horizontal stabilizer connected by the rotating shaft and attached to the original vertical stabilizer unfolds 90° along the rotating shaft, and the deployed spare horizontal stabilizer together with the stuck original elevator provides pitching moment for the aircraft.

The invention discloses the following technical effects: the invention does not affect the normal operation of the original empennage, and the aircraft load is basically unchanged, but can effectively reduce the probability of flight accidents caused by empennage faults, and reduce the pilot's burden in emergencies.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Figure 1 is a schematic diagram of the overall structure;

Fig. 2 is a schematic diagram of the deployment structure of the spare horizontal tail;

Among them, 1. Rotary shaft; 2. Rudder; 3. Spare elevator cabin; 4. Spare horizontal stabilizer; 5. Original horizontal stabilizer; 6. Original elevator; 7. Original vertical stabilizer.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The invention provides an aircraft tail, comprising: the original horizontal tail, the original vertical tail and a spare horizontal tail installed on the original vertical tail; the spare horizontal tail is installed on the original vertical tail through the rotation of the rotating shaft 1; The top of the empennage is perpendicular to the original vertical empennage.

The original horizontal stabilizer includes the original elevator 6 and the original horizontal stabilizer 5; the upward jamming angle of the original elevator 6 is 30°, and the downward jamming angle is 15°.

The original vertical stabilizer includes the rudder 2 and the original vertical stabilizer 7; the two side walls of the original vertical stabilizer 7 are inwardly provided with grooves for installing the spare horizontal stabilizer.

The spare horizontal stabilizer includes a spare elevator 3 and a spare horizontal stabilizer 4; the spare horizontal stabilizer 4 and the spare elevator 3 are both provided with two pieces, and are respectively installed in two grooves of the original vertical stabilizer 7 through the rotation of the rotating shaft 1.

The maximum upward deflection angle of the standby elevator 3 is 30°, and the maximum downward deflection angle is 15°.

A method for adjusting elevator jamming, comprising the following steps:

When the original elevator 6 is stuck, the spare horizontal stabilizer 4 connected by the rotating shaft 1 and attached to the original vertical stabilizer 7 is unfolded 90° along the rotating shaft 1, and the deployed spare horizontal stabilizer 4 is together with the stuck original elevator 6 Provides pitching moment to the aircraft.

Example 1:

Taking the original elevator 6 stuck upward as an example, as shown in Figures 1 and 2, the lift on the horizontal tail will decrease sharply, causing the aircraft's angle of attack to be too large. When the aircraft's angle of attack exceeds the stall critical angle of attack, the aircraft will be very A stall may occur. At this time, it is necessary to increase the lift at the horizontal tail, thereby reducing the nose-up moment to prevent the aircraft’s angle of attack from continuously increasing. The spare horizontal stabilizer 4 connected through the rotating shaft 1 and attached to the original vertical stabilizer 7 is deployed along the rotating shaft 1 by 90°, The rear spare horizontal stabilizer 4 and the stuck original horizontal stabilizer together provide the aircraft with a pitching moment, calculated by the fluid calculation software, as the spare elevator 3 deflects downward, the lift at the tail increases continuously, which greatly reduces the risk of the aircraft stalling. possible.

Example 2:

Taking the original elevator 6 stuck at the lower side as an example, the lift on the horizontal tail will increase sharply, the nose-down moment of the aircraft will increase, and the aircraft is likely to lose control and cause the aircraft to dive and descend. At this time, it is necessary to reduce the lift at the horizontal tail, thereby increasing the nose-up moment and preventing the aircraft's angle of attack from continuously decreasing.

The spare horizontal stabilizer 4 connected by the rotating shaft 1 and attached to the original vertical stabilizer 7 is deployed along the rotating shaft by 90°, and the deployed spare horizontal stabilizer 4 together with the stuck original horizontal stabilizer provides pitching moment for the aircraft. Calculated by the fluid calculation software, the spare elevator 3 is deflected upwards, and the lift force at the empennage is continuously decreasing at this time, which greatly reduces the possibility of the aircraft diving.

Further, calculate the lift coefficient under different working conditions, and calculate the impact on the lift coefficient after the original horizontal tail elevator is blocked and the backup tail is opened, so as to analyze and verify the feasibility of the scheme. In the calculation, the dynamic grid technology is used, the control equation uses the ALE finite volume method to describe the N-S equation of the compressible unsteady flow, and the ICEM software is used to draw the grid, and the grid is imported into the Fluent software to calculate the lift coefficient. The initial The working condition is that the angle of attack is 5°, and the incoming flow velocity is 68.9m/s. When the original horizontal tail elevator is stuck downward, calculate the change of the lift coefficient with the spare horizontal tail elevator upward deflection; when the original horizontal tail elevator is stuck upward, calculate the change of the lift coefficient with the spare horizontal tail elevator downward deflection. Based on the common elevators at present, the design with the elevator's up angle of up to 30° and down angle of up to 15° is adopted.

The empennage lift is calculated from the lift coefficient. The chord length of the original horizontal tail is 100, including the horizontal stabilizer length 71.483 and the elevator length 28.517, and the extension length is 120; the spare tail chord length is 100, including the horizontal stabilizer length 57.187 and the elevator 22.813, and the extension length is 100. The relationship between known lift coefficient and lift force is:

；

;

升力，/>

为空气密度，/>

为来流速度，/>

为机翼在/>

轴的投影面积，/>

为升力系数。由于本设计主要探究升力的变化趋势，不在于求解出精确的机翼升力大小，因此本文采用计算相对升力/>

来比较翼型升力的变化趋势:which is

lift, />

is the air density, />

is the incoming flow velocity, />

for the wing at />

the projected area of the axis, />

is the lift coefficient. Since this design mainly explores the change trend of the lift force, it is not to solve the precise wing lift force, so this paper uses the method of calculating the relative lift force

To compare the variation trend of airfoil lift:

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;

It is calculated that when the original horizontal tail is stuck upward, the lift force on the horizontal tail will decrease sharply, causing the aircraft’s angle of attack to be too large. When the aircraft’s angle of attack exceeds the stall critical angle of attack, the aircraft is likely to stall. Put down the spare horizontal tail, and deflect the elevator downward, so that the lift at the tail increases and the nose-up moment decreases, preventing the aircraft from entering a stall state; when the original elevator is stuck downward, the lift on the horizontal tail will increase sharply, causing the aircraft to If the angle of attack is too large, the aircraft may dive. If the spare horizontal tail is lowered and the elevator is deflected upward, the lift at the tail will be reduced and the nose-down moment will be increased, preventing the aircraft from falling into a dangerous dive state.

In describing the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or It should not be construed as limiting the invention by implying that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation.

The above-mentioned embodiments are only to describe the preferred mode of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (4)

1. An aircraft tail comprising: the device comprises an original horizontal tail, an original vertical tail and a standby horizontal tail arranged on the original vertical tail; the standby horizontal tail fin is rotatably arranged on the original vertical tail fin through a rotating shaft (1); the standby horizontal tail fin is arranged at the top end of the original vertical tail fin when being unfolded and is arranged vertically with the original vertical tail fin; the original vertical tail fin comprises a rudder (2) and an original vertical stabilizer (7); grooves for installing the standby horizontal tail wing are formed in the two side walls of the original vertical stabilizer (7) inwards; the standby horizontal tail comprises a standby elevator (3) and a standby horizontal stabilizer (4); the standby horizontal stabilizer (4) and the standby elevator (3) are respectively provided with two blocks and are respectively rotatably installed in the two grooves of the original vertical stabilizer (7) through the rotating shaft (1).

2. An aircraft tail according to claim 1, wherein: the original horizontal tail fin comprises an original elevator (6) and an original horizontal stabilizer (5); the upper deflection blocking angle of the original elevator (6) is 30 degrees, and the lower deflection blocking angle is 15 degrees.

3. An aircraft tail according to claim 1, wherein: the maximum upper deflection angle of the standby elevator (3) is 30 degrees, and the maximum lower deflection angle is 15 degrees.

4. A method of elevator drag adjustment comprising the aircraft tail of any of claims 1-3, comprising the steps of:

when the original elevator (6) is blocked, the standby horizontal stabilizer (4) connected through the rotating shaft (1) and attached to the original vertical stabilizer (7) is unfolded by 90 degrees along the rotating shaft (1), and the unfolded standby horizontal stabilizer (4) and the blocked original elevator (6) provide pitching moment for the aircraft together.

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