General Electric 90 engine

General Electric 90 engine

Abstract

The GE90 with an ultimate engine is the current record holder being the most powerful of all engines in the aviation industry for the production of thrust. This paper will analyze the specified fuel consumption posing rival aspect with the typical diesel engine that is large. The General Electric 90 engine as the advanced turbofan ultra high engine developed with specifications for the airliner Boeing 777 with a twin engine is a significant factor in the aviation industry as proven in the paper. The engine has specification of assembly form through an outsize cargo with the presentation of unique problems following the situations of emergency diversions. The paper also covers the General Electric 90 engine as a subject to many emergencies, which may lead to the breakdown in the operation of the Boeing 777.
Introduction

The General Electric 90 engine is the advanced turbofan ultra high engine developed with specifications for the airliner Boeing 777 with a twin engine. The GE90 with an ultimate engine is the current record holder being the most powerful of all engines in the aviation industry for the production of thrust. It currently rated at 115,000lbs of a considerable thrust for the demonstration of incredible reliability/performance margin with potentiality in future growth. The engine has been holding the record with an advanced highest-pressure ratio in comparison to any engine in aviation globally at 45:1. This has the meaning of the engine’s compressors having a compression atmospheric air with an approximation of 45 bars to 661 psi (Rao, 2011).

This happens prior to feeding the higher-pressure air into the specified burner. It has a tremendous power with efficiency when up in the sky. The engine has a specified fuel consumption posing rival aspect with the typical diesel engine that is large. The engine higher efficiency is due to the considerable ratio of compression that is high. Ratio of bypass that is high with the turbine high inlet temperature, which enables the conversion of higher energy gas for combustion into the horsepower shaft. This meant for driving the ducted fun that is massive at a lower rpm for the provision of the significant substantial functional portion of the total thrust (Rao, 2011).

 

 

 

 

Task 3

Historical account of the engine

Design and development

GE90 airflow simulation

 

The General Electric 90 engine launched in the year 1990 by the GE Aviation in association with the Snecma based in France, IHI based in Japan and the Avio based in Italy. It had later development in the late 1970s with a 10-stage higher-pressure compressor that is capable of developing the pressure ratio of 23:1 considered the industry record. The 2-stage Hp turbine that is air-cooled drives the engine. In October, the year 2003, the Boeing 777-300ER managed to break the ETOPS record with the engine installed. It managed to fly 330 minutes with one of its engines shut down. It flew from Seattle to Taiwan following the certification program of ETOPS. The engine is the largest engines of all time physically in the history of aviation. It has a fan diameter of up to 325 cm. The engines have specification of assembly form through an outsize cargo with the presentation of unique problems following the situations of emergency diversions (Rao, 2011).

The Airways of Britain as built by General Electric in conjunction with the specified companies first commissioned the first version of the engine. It is the considerable the most powerful of all engines. It had certification to take-off thrust at the 85,000lb. This was in consideration of the sufficed to the huge aircraft with the specification of the Boeing 777 having a sitting capacity of 230 tones. The engine is silent, fuel efficient and environmental friendly. The engine provides the specified airlines with an approximation of 5-6% improvisation in fuel burn with a lower noise pollution. The engine also produces an emission of 33% NOX lower compared to the bypass ratio engines (Rao, 2011).

Operational history

The GE90 engine mounted on the Boeing 777-200LR Air Canada in-flight over the nation of Siberia. The first flight with the engine delivered on 12^th of November 1995 with GE90-77Bs, which assumed services five days later successfully. There was an engine upgrade in the year 1998 following the temporary withdrawal earlier in 1997. This was due to the malfunction of the gearbox following an initial service bearing issues (Rao, 2011).

Records

The engine installed at 127,900 (lbf) holds the best record in consideration of the highest thrust. The record for the thrust was accomplishable following an hour engine test of stress with triple-red-line. For the proper accommodation of the increased torsion stress, a branded steel alloy of GE1014 had to undergo development to march the extreme tolerances (Rao, 2011). The engine set a new record on November 10, 2005. This was after powering a 777-200LR to mark the longest flight ever in a commercial airliner. The flight only had invited journalists and guests. The flight covered 13,422 miles in a mark of 1362 minutes from Hong Kong over the pacific to London, over the US continental then to London over the Atlantic. This is the longest flight ever in the history of a commercial airliner having passengers in 18.5 hours (Rao, 2011).

Task 4

The materials required for a complete construction of the General Electric 90 engine are six components. They are the materials that determine the efficiency of the engine. The engine has a composite fan that has twenty two complex wide cabled blades with a platform. Still part of the composite fan is a huge fan that allows greater air mass run with a fan gear that limits the noise that the engine produces. The fan has a design that entails a low angle speed with a pressure ratio that also allows minimal sound by the engine. On the fan there is a hybrid spinner that limits the core debris that is present in the ingestion process by the composite fan. The fan pressure has to be regulated in order to ensure that it is stable at all times maintaining an FPR of approximately 1.60 – 1.65.

On the general electric 90 engine there is another material that is important for the engines construction, which is the compressor. The compressor has a solid engine construction with a structure that is similar to the CFM56. On the compressor there is an uneven stumpy aspect ratio airfoil with a booster on three different stages of the engine. There is the combustor that is another additional key material for the engine construction that comprises of a dual dome which is an annular combustor out sourced from a military series that proved to be successful. The combustor ensures that the engine releases minimal Nitrogen Oxide emission.

The combustor also enhances negligible exhaustion of hydrocarbons that not yet burnt, minimal carbon monoxide. The combustor is one of the materials that ensuring enhanced functioning by the engine. If the combustor fails, then the general electric 90 engine is most likely not going to perform to its required levels. On the combustor, there is an alignment that facilitates prolonged existence of the engine. There is a turbine on the engine construction material that also serves several purposes on the functionality of the general electric 90 engine. It is built in such a way that it gives way to incorporation augmented pressure.

The engines dynamic stability is on the existence of the turbines depending on the way that they are built to enhance the efficiency of the engine. The turbines contain films that are in coil form to enhance a maximized the functioning experience of the turbine. There are multi turbines on the engine that enhance the cooling system of the engine. There are other separate materials that are required for the manufacturing process of the engine. The combustors are always in two pairs to emphasize in the efficiency of the engine making it a basic apparatus of the engine. The dual dome is made of material that conducts very minimal heat when the engine is running.

The turbines on the engine are in different stages that enhance the pressure that the composite fans take in as the engine is running. There is always a turbine that runs under maximized pressure while an alternative that is running on minimal pressure at the same time. This is necessary since they guarantee the gradual functioning of the engine. The pressure of the engine requires stabilization to ensure that it does not fail at any given instance. The engine assembling is necessarily on construction by professionals since they have the responsibility of ensuring that nothing is fixed where it is not supposed to be.

 

Task 5

Description of the ancillary components of the engine such as magnetos, fuel systems, turbochargers, high-tension ignition, igniters, thrust reversers, propeller hub design, turbine design, etc Note: Use the TCDS as a guide

Each ancillary component of the General Electric 90 engine is designed to perform specific functions. GE 90 is an ultra high bypass turbofan engine developed particularly for the twin engine Boeing 777. According to the Guinness World Record, it is the most powerful engine in the aviation for thrust production. The engine has specific fuel consumption that that rivals typical the large diesel engines. The high compression ratio, along with high turbine inlet temperature, and high bypass ratio converts most of the high-energy combustion gas into shaft horsepower. The process of converting the high-energy combustion gas into shaft horsepower leads to the high frequency of the engine. The conversion of high-energy combustion gas into shaft horsepower facilitates the process of driving away the massive ducted fan at low rpm. This would help provide the major portion of the engine’s total thrust.

The fuel systems is designed in such a way that it allows for complete combustion of the large capacity of fuel in the engine. A compressed air fed through the double annular burner with duplex nozzles and high temperatures compliments its exotic construction and in the end facilitates complete combustion. The double annular combustor (DAC), though a new concept in the aviation industry, is applicable in the GE 90 engines. The intention is to improve fuel burn and to minimize harmful emissions. At lower power settings, the outer ring is used with fuel only. However, as power increases, the inner ring is introduced which triggers the process of burning fuel in stages to enhance complete combustion. The magnetos are used to give power to the spark plug, which consequently initiates the mixture and cause. GE 90 engine is considered by aviation pundits as the most efficient, environment friendly and silent engine owing to its capacity to support complete combustion. The advancement sin the technology of GE engines make the fuel system more sophisticated compared to other engine models.

The turbine design enhances complete combustion of air and fuel when the jet engine is on flight. In addition, the propeller design hub facilitates movement of the aircraft on air making it one of the fastest GE 90 series. The Boeing 777 is a typical example of aircraft with such engine.

Task 6

The GE90 represents the investments of the GE that has a wide-body aircraft. Over the past couple of years, the engines chosen to power more than 50 percent of the recent aircrafts with the capacity of a minimum of 100 passengers. The engines have been chosen to be the best existing technology from the programs, was used by the NASA and the military programs due to the advanced technologies that provide a highly reliable, fuel efficient power plants that contribute to the generation of the wide-body aircraft. The originally certified machines of the year 1995, formed at the 84,700 lbs of the thrust. Currently, the machine have been advanced to the Boeing777 aircraft that is capable of flying to a further, faster and a more effective aspects of their predecessors. The powerful derivative of the GE90 is the sole power point of the Boeing longer range 777-300ER. The GE90-115B certified to the thrust and a couple of a broken number of the initial ground testing equipments. The GE90 has 110,000 lbs that enables it to have the twin-engine system freighter. In the Guinness Book of Records that the engine of the World most powerful Jet Engine was marked in the year 2001 whereby it recorded a score of 230,000 lbs. on the steady state while encountering the certification tests. Since the introduction of the Boeing, longer range 777, in the early 2000, noted as the best marketable engine of the aircraft in the entire aircraft groups.

Taxiing

This is the movement of the aircraft when it is on the ground under its own power. When the aircraft moves on tits wheels structure it is termed as one that is using the tax ways from one point of the airport to the other, for example when it is moving from a terminal to a runway. The aircraft is identified as the ground on which the yellow lines to prevent the collisions with the surrounding buildings. The taxiing motion identified to have a speed governor as it enables the pilot to minimize the speed used through prevention of skids. When an aircraft is landing, they have a higher chance of continuing to tax. The thrust propels from the propellers and the engine jets. This is the main reason why a vehicle before the engine pushes the aircrafts at the back of the building is prepared to tax.

Takeoff

This is the position whereby the flight undergoes the transition while moving along the ground through flying in the air, usually beginning at the runway. The engines run at a full power during the takeoff, whereby they tend to stop at the beginning line of the runway. The engines, for example the piston engines require frequent check up for the determination of any engine related problems. This makes the pilot to minimize the level of speed. The aircraft has the ability to climb the cruise in a safe and a more economical manner. The climbing is carried out through the lifting the force that exceeds the weight of the aircrafts. Once the act occurs, the aircraft appreciates through the altitude of the lifting forces and the weight is balanced. This increases the angle of attack enabling the pressure of thrust in the engines leading to an increase in the level of speed. The surface area compared to the shape of the wing produces a great lift, leading to the combination of the appliances. In majority of the machines, the engine thrust and the angle of the attacks is increased simultaneously producing a high climb.

Task 7

Describe emergency procedures this engine may require. Describe preliminary signs that failure might be imminent. Describe the actions a pilot could take to ameliorate the failure.

The General Electric 90 engine is a subject to many emergencies, which may lead to the breakdown in the operation of the Boeing 777. Consequently, the manufacturers have provided some of the emergency procedures, which may help in reducing the effect of the emergency. Some of the emergency includes engine fire, engine failure shutdown in midflight, and single engine out landing and total power loss (Lütjering & Williams, 2007). In case of engine fire, there should be a closing on the thrust levers followed by controlling the switch to the fuel. This would help in cutting off the fuel flow. Regarding the engine fire handle, there should be a pull on the engine to ensure. Regarding the APU, there should be an initiation on the APU to provide a chance for an alternative generator source.

The emergency involving failure shutdown mid flight will call for a closing on the thrust lever while also cutting off on the fuel flow. There should be setting of the fuel cross feed using the tank found on the failed engine. Then there should be a reduction on the altitude to allow for the acceptable power setting. The engine will also require the reduction in the cruise speed in order to reach at most 0.65. There should be a continuation on the flight to the destination, only if possible since attempts to go back to origin will make the ATC figure intentions and situations. For the emergencies involving Single Engine out landing, the engine will require application of flaps 20⁰C to allow for efficient landing. This will also allow the plane to approach without problems (Lütjering & Williams, 2007). The engine will also need the usage of rubber in order to balance the inadequacy of power. Further, there should be action to maintain the stay on the glide slope during the emergency. This should occur at all times of emergency. There should be translating the auto-brakes into MAX AUTO, in addition to avoiding the Thrust reversers associated to the rollouts. The engine will also require the involved individual to proceed with the normal landing after carrying out the procedures (Donachie, 2003).

The General Electric 90 engine will always exhibit preliminary signs, which indicate that there are potential failures. Some of the signs may be visible when there is the presence of cracked block that heads towards the intermix, failure of the cylinder lining and failure of the adjacent shaft. The cracked block always occurs when there the contamination of the coolant with oil. The creamy deposit occurring below the filler cap of oil may also contaminate the coolant leading to the cracked block (Donachie, 2003). The signs to this include steam originating from the exhausts found on the cold starts. The steam may stay for at least 5 seconds. Another sign is seeing coolant loss over some time. For the failure of the cylinder lining, the signs include coolant forcing its way out of coolant tank. This always occurs at higher pressure. The coolant may also tend to move from the exhaust system. The failure of the intermediate shaft will involve mechanical noise with subsequent stall.

The pilots have always established various solution that they can apply whenever the ameliorate failure occurs. The pilots would have to study the specific part exhibiting the failure signs followed by applying the appropriate solutions. For the cracked block associated with the way leading to the intermix, the pilots would need to replace the head as immediate as possible to stop the contamination with oil. The pilots may also need to seek for engine replacement (Donachie, 2003). The solution to the failure of the cylinder lining would involve the pilots applying hydraulic engine locks or relining the cylinder. For the failure of the intermediate shaft, the pilots would need to go for new engine.

Task 8

Make a list of maintenance requirements such as TBD times, Airworthiness Directives, Service Bulletins, instructions, and letters issued by the manufacturer. Pick three from the list and describe the process in detail.

Service bulleting

• Service bulleting is issued from the aircraft manufactures and they are automatically issued to the owner of an aircraft through the component manufacturer. Owners should be cautious as the service bulletins are sent automatically to see the maintenance of the providers.
• A service bulleting constitutes of the recommendation from the manufacturer to have the belief that the aircraft owner that complies with the reflection of the safety of a light in the issuing of the period. This results to the improvement of the development of the machine by the manufactures. This addresses the defects of the products of the published documentation.
• The manufactures responds in time to the situations that use different service bulletins that recommend for various type of inspections leading to the replacement of the components of maintenance in a specific manner and this limits its operations.
• The service bulleting is labeled and characterized by the manufacturer as a mandatory so that it compliances of the service bulletins that is required by the Federal Aviation Regulation (FARs).

 

 

• The airworthiness directive provided by the FAA states that the users of General Electric 90 Engines should put the engine through inspection associated with the FMS before putting the engine for any flight.
• Another Airworthiness directive was that the used FMS should always be subjected to recurring inspections within 90 days amidst the inspections.
• The TBD times provided for the General Electric 90 Engines includes FAA warnings on prevention of the expected additional ruptures on the shaft of the engine. This aided in preventing any threat of damage to the engines.
• The TBD times also provided that GE90 should undergo reverting to some of the internal coatings used on the engines. All the future engines will be using this type of lubricants.

 

References

Rao, J. S. (2011). History of rotating machinery dynamics. Dordrecht: Springer.

Garvin, R. V. (1998). Starting something big: The commercial emergence of GE aircraft    engines. Reston, VA: American Institute of Aeronautics and Astronautics.

Donachie, M. J., & Donachie, S. J. (2003). Superalloys: A technical guide. Materials Park, Ohio:      ASM.

Lütjering, G., & Williams, J. C. (2007). Titanium. Berlin: Springer.