RU80431U1 - DEVICE FOR PROTECTING A GAS TURBOUS ENGINE OF AN AIRPLANE FROM AN EXTERNAL OBJECTS AND BIRDS - Google Patents

Abstract

The utility model relates to means for protecting gas turbine engines of aircraft from foreign objects and birds.

The device comprises a mesh screen composed of two parts with overlapping contour of the air channel in front of the air intake and two diametrically arranged and mounted on the air intake bracket. The inner contour of the rim of the first part of the mesh screen coincides with the outer contour of the rim of the second part. Both parts of the mesh screen are planted in the place of their separation on a common axis with the brackets with the possibility of synchronous rotation of both parts of the mesh screen in front of the air intake in a horizontal position. Simultaneously with the rotation, the second part of the mesh screen is laid inside the first. The mesh in the mesh screen is formed of threads with a tensile strength of at least 230-270 cN / tex.

The technical result of the invention is to increase the reliability of the protection device and simplify its operation. 1 s.p. f-ly, 9 ill.

Description

The inventive utility model relates to a means of protecting gas-turbine, including turbofan, aircraft engines from foreign objects and birds.

The ingress of foreign objects from the surface of the airfield into the air intake by their suction is possible during engine tests in the parking lots, taxiing, take-off and landing, while it is possible that birds can enter the air intake. 80 percent of flight accidents occur on take-off and landing / 1, p. 7 /.

Statistics on the frequency, nature of engine damage and serious consequences resulting from the ingress of foreign objects and birds are hidden from public access. At air shows no traces of the means of protection of aircraft engines are visible.

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

For example, if a bird weighing 5 ... 8 kg gets into a “self-protected” airbus engine at an airplane speed of 300 km / h, it will cause a blow to the rotating fan impeller, comparable to a hammer blow.

There are designs in which the aircraft’s engines are protected from the absorption of foreign objects from the surface of the airfield during take-off and landing by blowing off the vortex formed in front of the engine / 2, p. 67 /.

The known device described in the application of Japan / 3 /, contains a set of fixedly mounted in front of the engine air intake

numerous tubes of spherical or conical shape and a connecting cylinder for tubes mounted coaxially with the air intake. Hot air is supplied to the tubes from the manifold, which is then exhausted out of the connecting cylinder.

Known protective devices using frames with nets of conical, spherical, cigar-shaped, stationary mounted in front of the air intake. These devices are described in US patents and Germany / 4, 5 /. Such devices in basic flight modes prevent the necessary air flow from entering the engine.

The known protection device is described in the copyright certificate of the USSR / 6 /. It contains a rotary panel in the form of a frame carrying a protective grill, which is located in the channel of the air intake. After takeoff, the protective rotary panel is insulated in the air intake channel, while landing, the protective rotary panel again closes the air channel. The design of such a protection device has the following disadvantages:

- it is intended for use in an air intake with a rectangular contour of the air channel;

- when a large bird gets in, its fragments will fall onto the protective rotary panel completely, without any possibility of throwing part of the fragments out of the air intake, which can cause a sharp reduction in the air flow into the engine and its surge;

- it cannot be used to protect a turbofan engine, in which the fan is located at the entrance to the air channel of the air intake / 2, p.10 /.

Closest to the claimed utility model is the protective device of the air intake described in the patent of the Russian Federation / 7 /. The protective device contains two sections in the form of a frame with a grid, rotated in the channel of the air intake.

Before starting the engine, the sections move to the released position and form an overlap of the air intake channel. After taxiing and take-off, the sections are retracted, are released again upon landing. This device has the following disadvantages:

- the air intake is filled with two frames with grids, which reduce the intake of air into the engine during take-off mode when it is operating at full power;

- the device mechanism contains many interconnected elements, which makes its operation and maintenance unreliable;

- when a large bird enters, its fragments will fall onto the frames with a grid of sections completely, without any possibility to discard part of the fragments outside the air intake, which can cause a sharp reduction in the air flow into the engine and its surge;

- this device cannot be used to protect a turbofan engine, in which the fan is located at the entrance to the air channel of the air intake / 2, p.10 /.

The objective of the claimed utility model is to increase the reliability of the protection device and simplify its operation and maintenance, in particular, to eliminate the disadvantages associated with the placement of the known protection device in the channel of the air intake.

The problem is solved in that the device for protecting the gas turbine engine of the aircraft from foreign objects and birds contains

a two-part mesh screen with overlapping air channel in front of the air intake, and two diametrically arranged and fixed on the air intake brackets designed to hold two parts of the mesh screen, while the inner contour of the rim of the first part of the mesh screen coincides with the outer contour of the rim of the second part with a gap and both parts of the mesh screen are planted in the place of their separation on a common axis with the brackets with the possibility of simultaneous rotation of both parts of the mesh screen in front of the air the fence in a horizontal position, and at the same time with the rotation, the second part of the mesh screen is laid inside the first. The mesh parts of the mesh screen are formed of threads with a tensile strength of at least 230-270 cN / tex.

The inventive utility model allows you to:

- withdraw the elements of the protection device from the air intake channel and thereby increase the air flow into the engine during take-off mode;

- to simplify the removal of the nets of the two parts of the mesh screen from the direct air flow by rotating the named parts in a horizontal position, while laying one part of the mesh screen inside the other part, while the resistance of the combined parts of the mesh screen to the air flow will be minimal;

- eliminate the risk of blocking the air channel by fragments of a large bird in a collision with it due to the location of two parts of the mesh screen in front of the air intake;

- apply a protection device for a turbofan engine, in which the fan is located at the entrance to the air duct of the air intake;

- apply for the manufacture of a mesh screen mesh threads with a tensile strength of at least 230-270 cN / tex / 8 /, which provides the mesh with the lowest resistance to air flow, high

strength and lack of hoods during impacts from a collision with a large bird, corrosion resistance (see. Calculations). Without such a mesh, the protection device is not complete.

Figure 1 shows a General view of the protection device in its original position.

Figure 2 shows a view And figure 1 is a front view of the protection device.

Figure 3 shows a view of B in figure 2.

Figure 4 shows a section GG in figure 1.

Figure 5 shows a section bb in figure 3.

Figure 6 shows a General view of the protection device with two aligned parts of the mesh screen in a horizontal position.

Fig.7 shows a top view of Fig.6.

On Fig shows a section DD in Fig.7 and fixing the ends of the threads of the nets.

Figure 9 shows a fragment of the grid for two parts of the mesh screen.

The device for protecting a gas turbine engine of an aircraft from foreign objects and birds comprises a mesh screen composed of two parts 1 and 2 (Fig. 2). Two brackets 3 are diametrically located and fixed on the air inlet (FIG. 1). the first part of the mesh screen 1 contains a rim 4 (figure 2) and a tie 5 (figure 3, 8), on which the mesh is stretched. The lever 6 is fixed on the rim 4 (Fig. 1), the holes are machined at the two ends of the rim 4, where the antifriction sleeves are inserted 7. On the screed 5 there is a depression K (Figs. 3, 5) to create the possibility of laying the rim of the second part 2 on it mesh screen. On the rim 4 is fixed a plate 8 for laying on it the rim of the second part 2 of the mesh screen (Fig. 8). The second part of the mesh screen 2 contains a rim 9 (figure 2), the outer contour of which corresponds to the inner contour of the rim 4, and a tie 10, (figure 3, 8), which are stretched

grid. The lever 11 is fixed on the rim 9 (Fig. 1), the holes are machined at the two ends of the rim 9, where the identification bushings 7 are inserted (Fig. 3). Rims 4 and 9 are made in cross section in the form of an oval to reduce resistance to air flow (Fig. 8). On the rims 4, 9, screeds 5, 10, holes were machined for the formation of mesh cells, for example, 25 mm in the light (Fig. 8). At the end of the holes on the rims 4, 9 and the ties 5, 10, holes 12, 13 are processed on one side (Fig. 8). The grids of the two parts of the mesh screen 1 and 2 are made by cross-weaving the threads 14 (Fig.9). The thread 14 is passed into the hole and tensioned, after exiting the hole, the thread 14 is wound twice with transmission into the hole, and at the outlet of the hole, the holes 12, 13 are filled with a hardening sealant (Fig. 8). After the sealant has hardened, the threads are cut, the holes are cleaned.

Parts 1 and 2 of the mesh screen are assembled by combining the holes at the ends of the rims 4, 10 with the holes in the brackets 3 and fastened by the axles 15, washers 16 and cotter pins 17, while the spacer ring 18 is installed (Fig. 3). After assembly, the brackets 3 are fixed to the power elements inside the air intake by fasteners 19.

At the end of the lever 6, the axis 20 is fixed to the lever 20, and at the end of the lever 11, the axis 21 is fixed to the lever 21 (Fig. 1), the free ends of the levers 20, 21 are brought together and connected by an axis to the cylinder head 22 of the hydraulic cylinder 23 (Figs. 1, 6).

The leverage system allows you to synchronously rotate parts 1 and 2 of the mesh screen in a horizontal position, and at the same time lay the second part inside the first.

The hydraulic cylinder 23 is located in the niche of the air intake, which is closed on its outer side with a removable streamlined cover 24 (Fig.7). The cover 24 according to the conditions of the actual layout may protrude from the bypass of the air intake.

A device for protecting a gas turbine engine of an aircraft from foreign objects and birds works as follows.

Before starting the engine, the parts of the mesh screen 1 and 2 by means of rigidly fixed levers 6, 11 and levers 20, 21 connected by an axis to the cylinder head 22 of the hydraulic cylinder 23, when the rod moves backwards, they rotate synchronously around the axes 15 in the brackets 3 until the rims 4 and 9 come in contact air intake. In this case, parts of the mesh screen 1 and 2 overlap the contour of the air channel. In this (initial) position, parts 1 and 2 of the mesh screen remain during taxiing, take-off engine operation and take-off. Foreign objects from the surface of the airfield are reflected by the mesh screen of the protection device. When colliding with birds, the parts of the mesh screen 1 and 2 take an impact, and the impact force can be significant. Upon impact, the bird breaks up into fragments, some of which are discarded upon impact, some are disrupted by the air stream. Small pieces of the bird will inevitably be drawn into the air intake and engine through the nets, but they will not be able to cause damage, while the engine manufacturers also took protective measures.

The use in the protection device of grids with smaller than 25 mm in the light cells can be confirmed by aerodynamic tests. After the take-off of the aircraft and the transition to the main flight modes through the forward stroke of the hydraulic cylinder 23 and the associated leverage system, the parts of the mesh screen 1 and 2 are synchronously moved to a horizontal position while laying the second part of the mesh screen inside the first part. The translation of the parts of the mesh screen from the initial position to horizontal should be performed when climbing, for example, 3 km, where the probability of collision with birds is much less. At this moment, the flight speed should not exceed 500 km / h due to the dynamic pressure of the air flow.

The resistance of the combined parts 1 and 2 of the mesh screen to the air flow will be minimal, this is also facilitated by the oval profile in the section of the rims 4 and 9. With a decrease in landing, the translation of parts 1 and 2 of the mesh screen to its original position (overlap) is performed as previously described. After landing and taxiing into the parking, parts 1 and 2 of the mesh screen are moved to a horizontal position for inspection of the front of the engine through the air channel. When servicing parts of the mesh screen 1 and 2 together with two brackets 3 can be disconnected from the air intake and removed. Maintenance of the hydraulic cylinder 23 and the lever system is performed when the cover 24 is removed from the outside of the air intake.

Based on the claimed utility model, aviation specialists can create the perfect gas turbine engine protection device for each type of aircraft.

INFORMATION SOURCES

1. Shumilov I.S. Aviation accidents: causes and possibilities of prevention. M., MSTU, 2006.

2. Soloviev B.A. The device and operation of the power plants of aircraft IL-96-300; TU-204; IL-114. M., Transport, 1993.

3. Japanese application JP2000128090, 09/05/2000.

4. Patent US 3871844, 03/18/1975.

5. German patent DE 19545806, 08.08.1996.

6. Copyright certificate of the USSR No. 717868, 01/27/1996.

7. RF patent No. 2271964, 10.28.2004.

8. Internet site http // www.advtech.ru // lirsot / produktarmos.htm. 07/04/2008.

9. GOST 2715-75 Metal wire mesh.

10. GOST 18143-72 Wire from highly alloyed corrosion-resistant and heat-resistant steel. Technical conditions

Claims (2)

1. A device for protecting a gas turbine engine of an aircraft from foreign objects and birds, comprising a mesh screen composed of two parts with overlapping air channel in front of the air intake, and two diametrically arranged and fixed on the air intake bracket, characterized in that the inner contour of the rim of the first part of the mesh screen matches with the outer contour of the rim of the second part and both parts of the mesh screen are planted in the place of their separation into a common axis with the brackets with the possibility of synchronous rotation about parts of the mesh screen in front of the air intake in a horizontal position and laying the second part of the mesh screen inside the first. 2. The protection device according to claim 1, characterized in that the mesh of the parts of the mesh screen is formed of threads with a tensile strength of at least 230-270 cN / tex.