WO2016095070A1

WO2016095070A1 - Protective apparatus for aircraft engine

Info

Publication number: WO2016095070A1
Application number: PCT/CN2014/001177
Authority: WO
Inventors: 戴明文
Original assignee: 江阴古贝叶工业技术开发有限公司
Priority date: 2014-12-19
Filing date: 2014-12-25
Publication date: 2016-06-23
Also published as: CN104608932A

Abstract

A protective apparatus for an aircraft engine, formed of three blades (5) made of carbon fibre material, a 120° angle being formed between the three blades (5), a caster being disposed at the tail end of each blade (5), said caster being mounted in a metal ring of a guide rail structure, and said metal ring being mounted on a cowl (1) of the engine of an aircraft. When the aircraft engine is in operation, the blades (5) rotate at high speed, forming a dynamic tightly protective cover for the engine cowl; approaching birds will be ejected by the rotating blades and will not be sucked into the engine, thus protecting the flight safety of the aircraft.

Description

Aircraft engine protection device

Technical field

The present invention relates to an aircraft, and more particularly to an aircraft engine guard.

Background technique

It is often reported that birds are rushing into the engine and causing damage to the aircraft. In the case of a bird crash, the engine sucking birds caused a large number of catastrophic accidents. For example, a three-issue DC-10 passenger aircraft in November 1975 When taking off in New York, an engine caught the bird and caused the plane to catch fire. 138 people on the plane fled the sea of fire, but the plane burned. On September 22, 1995, an E-3 early warning aircraft was hit by more than 30 Canadian geese. The No. 2 engine inhaled three and the No. 1 inhaled one, causing the plane to crash. None of the 24 people on board were spared. On November 10, 2008, the Irish Ryanair Boeing 737 aircraft crashed into the Italian capital Rome Ciampino airport due to the inhalation of the engine, causing five minor injuries; on November 14, 2008, the Spanish airline A319 from Tangier, Morocco The bird was struck during take-off, the No. 2 engine inhaled the bird, some of the compressor blades were damaged, and the plane returned urgently. On November 29, 2008, the Weiz Airlines passenger plane was attacked by a large group of birds after taking off in the Romanian capital, an engine. Failure, forced to land in the adjacent airport urgently; on January 15, 2009, when the US Airways Flight 1549 A320 took off in New York, both of them simultaneously inhaled the big bird while parking, and the aircraft was safely forced to land on the Hudson River; On the 24th of the United States, JetBlue's A320 took off at Orrland, and the right-handed bird was cancelled. On February 3, 2009, United Airlines' B757 was attacked by a bird when Denver took off, and the right-handed sucker broke. Air hood, flight cancellation.

Strictly speaking, it cannot be said that the bird hits the engine, but the engine should suck the bird; not only because there is a large relative speed between the aircraft and the bird, but also the working engine will have a large speed (the air flow rate at the engine inlet is about Inhaling a large amount of air for 100 to 120 m/s), and also inhaling debris such as sand, debris, birds, etc. in the air in front of the aircraft, which is so attractive that not only large birds can be inhaled, but also heavy People of dozens of kilograms can also be inhaled. For example, at around 14:00 on April 20, 2002, a Chinese international airline's crew was inhaled by a B767 engine that was being taxied to the take-off runway at the Kansai International Airport in Japan. The personnel died on the spot and the engine was broken. The aircraft had to replace the engine. In another example, on the afternoon of May 12, 2006, at the Harbin Taiping International Airport, a Boeing 737-800 passenger aircraft taxiing on the take-off runway inhaled a man on the ground into the engine, causing the man to die on the spot.

Boeing has conducted statistics on the company's B737, B747, B757 and B767 four aircraft, from January 1982 to June 1993, including bird strikes including impacts on the engine. About 3/4 of the total incident of the bird collision aircraft, the results are basically consistent with the statistics of the CAA and ICAO ICAO statistics, indicating that the majority of the bird collision incidents hit the engine, the main reason Yes: First of all, this is because the windward area of the engine and the nacelle of the engine accounts for a large proportion of the windward area of the entire aircraft. That is, when the bird hits the plane, the probability of hitting the engine is greater than hitting other parts of the aircraft.

The damage caused by the engine sucking birds is much greater than that of other parts of the aircraft. This is because the front end of the engine is a high-speed rotating fan blade. The circumferential speed of the blade tip is as high as 350-450 m/s. When the bird inhales the engine and hits it. When the fan blades are used, it causes a large damage. If the blade is broken, the fragment will flow to the rear with the airflow, and will flow to the booster compressor, high-pressure compressor, etc. after the fan, which will further cause more damage. In severe cases, the engine will stop; the fragment will be under centrifugal force. If the machine is broken, it will damage other parts of the aircraft, causing "secondary damage" that would harm the safety of the aircraft.

As the number of bird sucking events increases, the weight of birds sucking into the engine is also on the rise, and the damage caused is becoming more and more serious. People adopt different measures against birds and engines, which will cause less damage.

For birds, the main reason is to drive birds away from the airport airspace. The main way to drive them is to intimidate, destroy habitats and migrate habitats. However, these methods have limited effects. For example, the use of gas cannons to drive away birds and scare away birds with horror eyes with huge eye patterns will become a common cause for birds to withstand reflexes. Recording and repelling birds are geographically restricted and must be used. The recording of local birds will have a better driving effect. Hunting is a violation of the principle of ecological protection; raising raptors is a way of bird control, artificially domesticating and raising a certain number of raptors at the airport, regularly flying, driving away wild birds; destroying habitat and using birds to dislike, But chemicals that have no effect on the environment will cause birds to abandon the airport as a habitat.

The design of the engine has been improved. Therefore, in the revised airworthiness regulations, the requirements for the bird suction test have been greatly revised to ensure that the engine is seriously damaged after the bird is sucked. The requirement after the bird sucking test is that the sucking bird cannot have more than 25% thrust loss, and the engine is required to stop after 5 minutes of sucking the bird, and does not cause a potentially dangerous state. The big bird can't cause the engine to catch fire, rupture, generate excessive load, and lose parking capacity.

Also, a protective measure that people can easily think of is to install a protective cover on the engine to prevent birds from being inhaled. According to the conservation of momentum, the momentum is proportional to the square of the velocity, and the velocity is also large. The diameter of the air inlet of a civil aircraft jet engine is 3-4 meters, and the suction of the low pressure rotor is extremely large. This requires that the protective cover is quite strong and the hole of the protective cover is small enough, which will cause the engine to have insufficient oxygen to reduce the thrust and affect the engine. The stability of the work; and, once a bird is caught, the sucked bird blocks the covered mesh and further reduces the amount of oxygen. The intake port of the civil aircraft is round and the duct is short, which is not conducive to the installation of the retractable net cover. For civil aviation, there are almost no birds in the stratosphere. Mainly during the take-off and landing phases, as well as encountering airflow avoidance issues.

In order to reduce the damage caused by the engine sucking birds, the engine development unit should strengthen the ability to resist foreign objects against the vulnerable components such as engine fairings, fan blades and containment rings in accordance with the revised airworthiness regulations. The strength design and rigorous test assessment and complete machine test to ensure that the engine does not have serious consequences after sucking the bird.

Summary of the invention

Wind power generation uses wind power to drive the windmill blades to rotate, and then increases the speed of rotation through the speed increaser to promote the generator to generate electricity. According to the current windmill technology, stiffness is also a very important indicator for the blade. Studies have shown that the carbon fiber / carbon fiber composite blade stiffness is two to three times that of FRP composite blades. Although the performance of carbon fiber composites is much better than that of glass fiber composites, it is expensive, which affects its application in a wide range of wind power generation. Graphene is a plane composed of carbon atoms with sp2 hybrid orbital to form a hexagonal honeycomb lattice. The film is a two-dimensional material with only one carbon atom thickness. Due to the nature of the chemical bonds between the carbon atoms, graphene is very tenacious: it can bend to a large angle without breaking, and it can resist high pressure.

In view of the fact that the currently ubiquitous aircraft engine has the inevitable huge economic loss and personal injury caused by the inhalation of birds during the flight, the present invention is based on the principle of wind blades and combines the high strength and toughness characteristics of new materials carbon fiber or graphene. Designed a new type of engine cover. The engine cover is designed as a structure of three wind blades, and high-strength carbon fiber is used. Although the unit cost is high, since the diameter of the fairing of the aircraft engine is only about 4 meters, the total cost is not expensive. Due to the structure of the wind blade, the stress generated by the suction force of the engine can be used to rotate the blade at a high speed, so that the accumulated stress is prevented from breaking the blade, and the rotating blade forms a dynamic shield for the engine fairing. If a bird or other item is inhaled near the fairing, the high-speed rotating blade will eject it without entering the engine compartment, causing great damage. Save their unnecessary losses and even personal injuries.

The specific design of the present invention is to fabricate a metal ring that matches the fairing of the aircraft engine. The metal ring is a rail structure, and then the three blades are assembled into a wind turbine blade structure of 120° between each. The end legs of the blade are provided with casters, and the blade casters are embedded in the ring guide. The blade is made of a carbon fiber material. The metal ring is then placed over the fairing, and finally the bolt or rivet holds the metal ring. In order to enhance the strength of the blade, the blade is made of carbon fiber or graphene material.

Compared with the existing technology for preventing engine bird sucking, the present invention has three distinct advantages: 1) the scheme is simple and the cost is low, and the cost is higher than the design of the technology whether the airport is repelling birds or improving the engine strength; 2) sufficient Using the principle of wind power generation, the huge suction force of the engine is converted into the power of the high-speed rotation of the shield blades; 3) The dynamic shield with only three blades has little effect on the intake air volume of the engine compartment, and the protective screen formed can completely eliminate Birds or people are drawn into the tragedy of the engine, recovering huge economic losses and protecting passengers' flight safety. New materials for graphene and carbon fiber can greatly increase the strength and service life of the blade.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 is a side view of the present invention;

Figure 2 is a front cross-sectional view of the shield device;

among them:

1 engine fairing 2 shield hub 3 shield ring guide 4 bolt 5 blade 6 roller

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific examples:

Firstly, several equidistant bolt holes are arranged in the outer diameter of the fairing. According to the outer diameter of the fairing 1 of the aircraft engine, a matching protective ring is designed. The preferred material is titanium alloy. The guide rail 3 has a plurality of bolt holes evenly distributed on the ring, and its position is matched with the screw hole of the fairing. The ring can be opened so that the rollers 6 of the three blades of the shield can be placed in the guide rail 3, and then the ring is fixed so that the three rollers 6 are all embedded in the guide rail. The three blades are fixed to the shield hub with an angle of 120° therebetween, the blade 5 is a twisted wind blade structure, and graphene or carbon fiber is used as the blade material, and the hub 2 protrudes from the fairing. Finally, the protective cover of the blade is installed, the name of the outer diameter of the fairing is placed and the respective screw holes are aligned, and then the shield is fixed by the bolt 4. During the flight of the aircraft, the engine generates a huge suction force, which drives the three blades to rotate at high speed in the guide rail 3, forming a dynamic and tight protective net for the engine compartment; if there are birds or other objects being sucked into the vicinity of the engine compartment, high speed The three blades that rotate will pop it out to avoid being sucked into the engine, thus protecting the flight safety of the aircraft.

Claims

An aircraft engine guard characterized in that the engine guard consists of three blades, three blades being mounted in a metal ring mounted on a fairing of the aircraft engine.
The aircraft engine guard according to claim 1, wherein said three blades are 120° apart, and the ends of the blades are provided with casters, said blades being made of a carbon fiber material.
The aircraft engine guard of claim 1 wherein said metal ring is a rail structure.
An aircraft engine guard according to claims 1 and 3, wherein said vane casters are embedded in said annular guide rail.