RU202850U1 - Protection device for a gas turbine engine of an aircraft from the ingress of foreign objects and birds - Google Patents

Abstract

The proposed utility model relates to the field of aviation, in particular, to the means of protecting aircraft gas turbine engines from the ingress of foreign objects and birds, and can be used in the production of such devices. The technical result is to protect the engine and ensure the air flow of the required value passing through the protection device into the air intake. The technical result is achieved due to the fact that the device for protecting the gas turbine engine of the aircraft from the ingress of foreign objects and birds, containing a protective element that blocks the inlet of the air intake, while the protective element is a slotted conical fairing, consisting of separate elastic rods of circular cross-section, while convex outside the rods are fastened together in the upper part of the fairing by a conical metal shell, and in the lower part at equal distances from each other they are fixed to the side of the cylindrical shell and have two undulating bends in the lower part of the fairing. 3 ill.

Description

TECHNICAL FIELD OF USEFUL MODEL

The proposed utility model relates to the field of aviation, in particular, to the means of protecting gas turbine and turbofan aircraft engines from the ingress of foreign objects and birds and can be used in the production of these devices.

LEVEL OF TECHNOLOGY

The ingress of foreign objects from the surface of the airfield into the air intake by sucking them in is possible during engine tests at parking, taxiing, takeoff and landing, while it is possible for birds to get into the air intake.

On the occasion of the emergency landing of an aircraft with a seagull in its engine on a corn field near the Sheremetyevo airport, RBK TV channel with invited experts carried out a dismantling of the “flights”, from which the following became known:

1. Tens of millions of rubles are spent on fighting birds near airfields in the Russian Federation. At the same time, feathered predators and their voices from "chants" are used, removal of garbage dumps from runways, and more.

2. On some runways, when illuminated at night, migratory birds made a halt, that is, they rested.

3. They also talked about a trial test of a protective device against the ingress of birds into the aircraft engine, which did not meet the requirements due to a decrease in engine power due to a lack of air flow held back by this device.

This is the situation in aviation not only in the Russian Federation, but in almost all countries. There are inventions of devices for protecting engines, but airplanes fly without them. And the number of accidents due to birds entering the aircraft engine is only increasing. The reason for this situation is most likely the lack of adequate protective devices.

Statistics on the frequency, nature of engine damage and serious consequences as a result of foreign objects and birds falling into them are hidden from free access. No traces of protection equipment for aircraft engines are visible at air shows.

Perhaps, on the one hand, the engines are produced "self-protected", on the other hand, the consequences of the ingress of foreign objects and birds into the engine are considered a natural phenomenon, and not a consequence of the lack of protective equipment.

Not only birds, but also people are drawn into the aircraft engine.

Source: http: //www.ntv.ru/novosti/1736542/

In 2012, pulled into the engine of a mechanical engineer at Texas El Paso International Airport.

Source: http: //fishki.net/anti/1278652-chelovekpi-zasosalo-v-turbinu-samoleta.html

At the Sheremetyevo airport, I. Efimov was sucked into a Boeing-737 turbine.

This tragedy also happened in some other cities.

It makes little sense to list where and when the plane crashed with a bird in the engine, but it is enough to cite the data of the International Civil Aviation Organization in Montreal, which every year registers about 5400 aircraft collisions with birds. Even when these accidents do not threaten the safety of people, they cause colossal financial losses.

Of the considered a large number of patents for engine protection devices, the known protection devices are somewhat similar in shape (analogs) to the claimed ones using frames with conical, spherical, cigar-shaped grids, stationary fixed in front of the air intake, described in US patents US 3871844, 03/18/1975 and Germany DE 19545806, 08.08.1996. In basic flight modes, such devices prevent the necessary air flow from entering the engine.

The closest in technical essence (rebound and sliding of the device) to the claimed protection device (prototype) is the "protective block of the aircraft engine from the ingress of foreign objects and birds" patent No. 2666081C1. The invention presents several design options and drawings.

In the 5th embodiment, FIG. 1 a protective block of an aircraft engine from the ingress of foreign objects and birds, containing a protective element that blocks the inlet of the air intake, characterized in that a protective screen of free rotation rollers is installed in front of the air intake, fixed to the aircraft engine body, while the plane of the air intake can be made traditionally vertical, and the plane of the protective shield is made inclined or arrow-shaped, while the angle of inclination of the protective shield is 45 ° ± 15 ° relative to the longitudinal line of the fuselage.

The central roller 11 of free rotation, located in front of the "arrow-shaped protective block", is made stronger and larger in diameter.

The frame of the protective screen is attached to the aircraft engine block by means of bolts and nuts. The air intake can be rectangular or round or oval. Rollers of free rotation 3 on a "protective screen", arrow-shaped are installed vertically or horizontally relative to the horizon. The block is structurally adapted to the specific aircraft of FIG. one.

The work of the protective block of the aircraft engine from the ingress of foreign objects and birds is carried out as follows:

Aircraft 1, both passenger and military, operate normally. Birds 5 fly to the frontal plane of the air intake and fall on the protective screen from the rollers of free rotation. Each bird 5, leaning on at least two rollers at the same time, rolls over the protective screen and unharmed 6, slightly deviating from its course, flies further.

The disadvantages of this block of protection are:

1. A very complex and expensive design and has a large windage, which does not allow the oncoming air flow.

2. Screens change the trajectory not only of birds, but also of the oncoming air flow, which, due to ejection (drawing in, sucking air from under the screen), additionally reduces the air flow.

3. Maintenance required (inspection, periodic lubrication, etc.)

The technical problem solved by the utility model is the reliable protection of the engine and the passage of the necessary air flow through the protective device.

DISCLOSURE OF THE USEFUL MODEL

The specified technical problem is solved due to the fact that the device for protecting the gas turbine engine of the aircraft from the ingress of foreign objects and birds, containing a protective element that blocks the inlet of the air intake, while the protective element is a slotted conical fairing, consisting of separate outside convex elastic rods with two undulating bends in the lower part of the fairing, fastened to each other in the upper part of the fairing by a conical metal shell, and in its lower part at equal distances from each other are fixed to the side by a cylindrical shell fixed in the engine air intake.

SIGNIFICANT DIFFERENCES AND TECHNICAL RESULT

USEFUL MODELS

Significant differences of the proposed slotted fairing are its taper, the presence of a bulge on the outside of the rods and two undulating bends in its lower part. These significant differences ensure the achievement of the technical result - giving the fairing the properties of mechanical shock absorption and the ability to adjust (increase or decrease) the total throughput area of the fairing slots by reducing or increasing the length of undulating bends and rods during its design.

BRIEF DESCRIPTION OF DRAWINGS

The design of the fairing is shown in FIG. 2. Figure 1 shows the design of the prototype, which is used to illustrate the technical result achieved by the proposed utility model.

The design of the fairing contains a metal conical shell 1, fastening together in the upper part of the fairing elastic rods 2 with bulges on the outside with two wave-like bends 3 in the lower part of the fairing, fixed at equal distances from each other to the side of the cylindrical shell 4, fastening hole 5 on the shell for aircraft engine mounts 6.

IMPLEMENTATION OF THE USEFUL MODEL

From the point of view of design, the design of the fairing turned out to be openwork (openwork (fr.) - through, lattice, transparent; skillfully and delicately made) Fig. 2. (shows a vertical section of the fairing mounted on the engine). The conical shell secures the elastic rods with bulges on the outside of the circular cross-section with two wave-like bends in the lower part of the fairing and gives the taper of its structure no more than 60 °.

The elasticity created by the bulges and undulating bends of the rods softens (cushions) the blow of the bird, both from above and from the sides of the fairing. In addition, the protuberances of the rods for most of their length maintain a set distance between them in the lower part of the fairing, helping to ensure the necessary air flow entering the engine air intake. External bends, moving the rods away from the engine casing, form the fairing diameter larger than the engine diameter, so that the bird would slide past the engine casing along at least two rods.

To pass the necessary air flow for the engine, the total area of the fairing inter-rod space must be significantly larger than the area of its air intake channels.

To increase the inter-rod area of the fairing, it is necessary to increase the length of the bends and rods (to provide the required taper), to reduce the area, to reduce the length of the bends and the length of the rods (when designing the fairing).

The selection of the required ratio of the areas of different sizes of fairings and air intake is possible only by testing on a real aircraft engine. On the first fairing to be tested, its diameter should be greater than that of the engine, and the length of the rods from the outer bend to the upper cowling should be in a straight line equal to the length of the lower fairing diameter.

EXAMPLE OF DETERMINING THE RATIO OF AREA CIRCUIT AND AIR INTAKE OF THE ENGINE

Calculation of the fairing parameters.

Initial dimensions of element diameters:

1. The air intake is 60 cm.

2. The cylindrical shell is 70 cm.

3. The fairing, taking into account the bending length (5cm), is 80 cm.

4. Bars of round cross section is 10 mm.

5. If the size of the bird is more than 10 cm, then the distance between the outer bends of the fairing rods is taken (or set) equal to 10 cm.

Calculation of the length and areas of the fairing elements.

1. The length of the convex section of the rod in a straight line is equal to the length of the diameter of the fairing (80 cm).

2. The circumference of the cylindrical shell:

L _c = πD = 3.14⋅70 = 219.8 cm.

3. The circumference of the fairing.

_{4.L о} = πD = 3.14⋅80 = 251.2 cm.

5. The distance between the fastenings of the rods on the cylindrical shell is equal to: L _c / 22 = 219.8 / 22 = 9.9 cm.

6. The area of one slot is equal to the product of the length of the rod by the length of the distance between the rods in the middle part of the fairing 5.0 =80 = 400 cm ² .

7. The total area of the slots is 400⋅22 = 8800cm ² .

8. Area inlet πD ^2/4 = 3,14⋅3600 / 4 = 2826 cm ^2.

9. The coefficient of excess of the fairing slots area over the air intake area is 8800/3826 = 3.1 times.

Conclusion: the air flow entering through the fairing is much higher than through the prototype.

The work of the fairing is shown in Fig. 3, the flying aircraft 1, the fairing is installed on the engine 2, the flying birds 4, the trajectory of the birds 3 and 5 that bounced back, the birds 6 slipping off.

TECHNICAL RESULT OF THE UTILITY MODEL

The advantage of the proposed fairing in comparison with the analogue and the prototype is its conical shape, which forms a scanty windage, the flexibility of the rods, allowing the birds to easily and simply slide along the rods without touching the engine skin.

A design feature of the supplied fairing is the ability to provide the necessary air flow during its design, by setting the required area of the fairing slots, changing the length of the undulating bends and rods.

Claims (1)

A device for protecting a gas turbine engine of an aircraft from the ingress of foreign objects and birds, containing a protective element that closes the inlet of the air intake, while the protective element is a slotted fairing, consisting of separate elastic rods of circular cross section, characterized in that the slotted fairing has a conical shape, with convex outside the rods are fastened to each other in the upper part of the fairing by a conical metal shell, and in the lower part at equal distances from each other they are fixed to the side of the cylindrical shell and have two undulating bends in the lower part of the fairing.

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