GB2467567A

GB2467567A - Protection of jet engines from bird-strike and foreign object debris

Info

Publication number: GB2467567A
Application number: GB0901975A
Authority: GB
Inventors: Cyril Staley
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-02-06
Filing date: 2009-02-06
Publication date: 2010-08-11
Also published as: GB0901975D0

Abstract

A replaceable one-piece jet engine housing extension 2 integrally constructed in combination with a physically substantial perforated plate separator 3 that has no small or moving parts to be positioned forward of the engine's turbine blades such that it effectively prevents Birds and Foreign Object Debris from damaging them without adding excessively to the engine's 1 drag co-efficient or unacceptably increasing fuel consumption.

Description

PROTECTION OF JET ENGINES FROM BIRD-STRIKE AND

FOREIGN OBJECT DEBRIS.

Technical Field of Invention.

This invention relates to a means of preventing potential damage to jet engines due to Bird-Strikes or ingestion of Foreign Object Debris.

Background.

Presently, when Foreign Object Debris is thrown up from a runway into an aircraft's jet engines, catastrophic results are likely. On occasion such events have resulted in the total loss of aeroplanes together with the demise of many if not all of their passengers and crews as happened to Concorde at Paris. Similarly, forced landings and crashes are likely when birds penetrate jet turbines as recently occurred at New York where the craft had to be ditched in the River Hudson. Serious damage and loss of life may also extend to property and persons at crash sites in densely occupied airport localities after taking off or landing due to debris on the runway and the prevalence of birds during low level flight entering engines.

When a jet's blades, (which rotate at some 10,000 RPM), are struck by even quite small objects they may cause out-of-balance forces or even break blades loose which then systemically extends destruction throughout the engine which generally further endangers the aircraft as engine fires frequently result.

However, due to the necessity of placing ingestion protection forward of the turbine blades, measures such as lightweight mesh and barred grills have not been adopted on account of their inherent fragility and tendency to incur stress fractures and break-off damage occurring. Alternative methods of using a deflective shield have also been discounted as designs have involved radically diverting the air flow entering the engine causing an unacceptable increase in drag resistance which in turn reduces engine power and efficiency while adversely increasing fuel consumption. For these reasons jet aircraft operate without engine Foreign Object Debris or Bird-Strike ingestion protection, leaving them at risk during every flight.

Summary of the Invention.

This proposal seeks to overcome the above stated problems by providing a replaceable one-piece jet engine housing extension integrally constructed in combination with a physically substantial perforated plate separator that has no small or moving parts to be positioned forward of the engine's turbine blades such that it effectively prevents Birds and Foreign Object Debris from damaging them without adding excessively to the engine's drag co-efficient or unacceptably increasing fuel consumption.

The optimum design to ensure maximum operational criteria may be ascertained during wind tunnel tests utilising housing/separators of various dimensions. These may be shaped to suit the engine's air intake profile, i.e. circular, square, rectangular, oval etc. as various engine intakes dictate. Disabling objects may be cannon-fired into the separator, (as per standard aviation test practice), to determine engine sustainability under Foreign Object Debris and Bird-Strike simulated conditions. During routine maintenance under crack detection inspection, if necessary the complete unit may be dismounted and replaced in its entirety.

Brief Description of the drawings.

The invention will now be described by way of example and reference to the accompanying drawings in which: Figure 1 shows a typical jet engine whose casing I has an extension housing 2 within which is integrally combined a substantial perforated plate separator 3 being held in position by triangular support webs 4, the whole being one single item of sturdy stress-relieved construction. The net free area of the separator 3 needs to be well in excess of the engine's total annular air passage area. Its holes should be as large as is consistent with preventing potentially damaging material from passing through to the turbine blades. This is in order that its inherent additional drag is minimised but the holes should not be too large as to cause weakness in the structure. The drag factor may be adjusted by altering the length of the housing 2 and separator 3. To reduce weight the support webs 4 may have a series of large variable sized holes provided throughout their length.

Figure 2 shows a typical commercial aeroplane encountering a flight of geese whose engine I is protected by the housing 2 having an internal separator 3 to prevent birds and debris from damaging the jet turbine.

Claims

Claims.1/I claim ajet engine housing extension containing a perforated plate separator positioned forward of the engine's turbine blades to prevent damage from Foreign Object Debris and Bird Strikes.