Informative

Jet Engines: How They Work and Power Modern Aviation?

Published

5 months ago

21/04/2023

via Aviation Business Middle East

Jet engines revolutionized air travel over half a century ago, propelling humanity to new heights of speed, efficiency, and accessibility. Understanding the intricate workings of these powerful engines can be a daunting task, but with the right guidance, it becomes an intriguing exploration of modern aviation technology. In this article, we will demystify jet engines and delve into their inner workings, from gas turbines to their incredible material science.

The Gas Turbine: The Heart of Jet Engines

The gas turbine serves as the driving force behind jet engines, using the Brayton cycle process to create pressurized gas for generating electricity or supplying kinetic energy to aircraft. In all modern gas turbines, combustion of fuels like natural gas, kerosene, propane, or jet fuel generates heat that expands air, propelling the turbine into action.

Key Components of Gas Turbines Although gas turbines may seem simple in theory, they consist of three primary components:

Compressor: Captures air from outside the turbine and amplifies its pressure.

Combustor: Burns fuel, producing high-pressure and high-velocity gas.
Turbine: Harvests energy from the gas flowing out of the combustor, as illustrated in the diagram below:

Jet Engines — This diagram shows the primary components of gas turbines, via ***Energy Education***

a. Compressor Functionality:

As shown in the diagram above, the compressor pulls in air from the left, and numerous fan blades compress the gas. Some turbines can achieve air pressure up to 30 times greater than the initial input pressure.

b. Combustor Operations:

High-pressure air enters the combustor, where a constant fuel injection maintains a steady flow of energy throughout the turbine.

c. Turbine Performance:

The turbine, linked to the compressor blades by a shaft, rotates independently. The hot gas passing through the turbine allows it to reach remarkable speeds. The turbine connects to an output shaft, generating an impressive amount of horsepower—large airplane turbines, for example, can generate nearly 110,000 hp, which is double the power output of the Titanic.

Turbofan engines, which power most modern commercial aircraft, belong to a family of engines called gas turbines. This family also includes engines used in helicopters, small power plants, and even certain types of tanks. The term “turbine” provides insight into how these engines function. Like wind or steam turbines, gas turbines rely on spinning to generate power, with pressurized air driving the rotation.

Fuel and Pressurized Air

Gas turbines need to produce highly pressurized air to maintain a continuous flow of power to the engine. To accomplish this, they burn energy-dense fuels like jet fuel, kerosene, or natural gas. Combusting these fuels expands the air, creating a rush of hot gas that spins the turbine.

The Four-Step Process: Suck, Squeeze, Bang, Blow

Before delving into the detailed workings of gas turbines, it’s essential to understand the basic four-step process that drives these engines: suck, squeeze, bang, and blow. This simple process helps explain how gas turbines harness the power of pressurized air and fuel combustion to generate energy for aircraft propulsion.

Sucking Air In
- Air is sucked into the engine from the front using a large fan, typically visible when looking at a plane head-on.
Compressing the Air
- The air is then compressed in the next stage of the engine, referred to as the “squeeze” phase. A second fan increases air pressure by approximately eight times, significantly raising its temperature in the process.
Igniting the Fuel-Air Mixture
- Fuel mixes with the compressed air and ignites, producing the “bang” and generating power. The hot, high-pressure air rushes past a set of turbine blades, causing them to spin. The turbine connects to the compressor and fan via an axle, so as the gases turn the turbine, the inlet fan and compressor fan also spin.

Creating Thrust
- The rapidly moving air propels the aircraft forward. Military jets and select passenger planes may use afterburners, which inject fuel directly into the exhaust jet for additional thrust. However, for most passenger planes, the force generated by the moving air is sufficient to provide adequate forward motion for the wings to create lift.

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Designing Jet Engines: Challenges and Innovations

High Pressures and Temperatures

Though the basic principles behind jet engines may seem simple, designing them involves overcoming numerous challenges, particularly the extreme pressures and temperatures involved. Combustion chambers, where compressed air mixes with fuel, can reach temperatures exceeding 900°C (1,650°F).

The Quest for Suitable Materials

Traditional materials like steel proved unsuitable for withstanding the intense heat and pressures within jet engines, leading manufacturers to search for alternatives. Nickel-chromium alloys emerged as an ideal solution, offering lightness, affordability, strength, corrosion resistance, and the ability to retain integrity at up to 85% of their melting point (1,455°C or 2,651°F).

Cooling Strategies and Ceramic Coatings

To maintain the integrity of turbine components operating in temperatures exceeding their melting points, engine manufacturers employ ceramic coatings and cooling mechanisms. The coatings reduce heat penetration, while cool air is channeled to the blade surfaces from further up the engine and distributed through tiny holes. Neil Glover, Rolls-Royce chief of materials, explained in an interview with The Engineer that these measures keep the metal from melting, despite the extreme temperatures in the surrounding environment.

Advanced Materials Technology

Materials technology has progressed even further, manipulating the metal’s atomic structure to enhance its integrity. The tiny crystals comprising metals are engineered to grow in the same direction, eliminating weaknesses typically found at crystal boundaries. As a result, turbine blades are essentially gemstones, featuring a single atomic lattice throughout their structure.

Refining Nickel Alloys

Over time, manufacturers have refined nickel alloys by creating new mixes and adding different elements. This innovation allows turbine designers to tailor the perfect blend for each engine component, significantly enhancing overall performance.

The Balancing Act: Engine Size, Bypass Ratio, and Materials

The Bypass Ratio:
- Turbofan engines have generally increased in size as designs have evolved and improved. A significant portion of the thrust generated is due to incoming air being diverted around the compressor and turbine. The difference in the volume of air delivered to the turbine compared to the air bypassed is known as the “bypass ratio.” Engine efficiencies improve by increasing the bypass ratio, which typically involves creating a larger diameter engine.
The Weight Conundrum
- However, enlarging the engine also increases the weight of the fan sections, leading to heavier engines. For every additional kilogram of weight in the fan section, an extra 2.25 kg of support structure is required in the engine and wing.
Composite Materials: The Solution
- To counteract the increased weight from larger, more fuel-efficient engines, manufacturers have turned to composite materials as substitutes for metals. Ceramic matrix composites (CMCs) are as durable as metals but weigh only a third as much as nickel alloys.

The GE9X: A Modern Marvel
- The GE9X, currently the world’s largest engine for the Boeing 777X, utilizes composite materials in its fan blades and casing, as well as CMCs in the turbine and combustor. This powerful, lightweight, and resilient engine boasts a 10% improvement in fuel efficiency compared to its predecessor, the GE90, and is also the quietest engine ever produced by General Electric.

Read also: The Purpose Of Jet Engine Spirals

The Bottom Line

Jet engines have come a long way since their inception, with constant innovations and improvements in design, materials, and efficiency. This fascinating exploration of jet engines reveals the incredible engineering feats and cutting-edge materials science that enable us to travel the world in record time. As aviation technology continues to advance, we can only imagine what the future holds for jet engines and air travel.

What other innovations do you think the future holds for jet engine technology? Share your thoughts in the comments below!

Sources

Simple Flying

Energy Education

Related Topics:Aerospace engineering engines Jet Engines

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Informative

Are you dreaming of becoming a pilot? Aer Lingus & British Airways Cadet Program Paves the Way to a Flying Career

Published

1 month ago

14/08/2023

Giuliano

Embarking on an aviation career has always been a dream for countless individuals who are passionate about flying. The Aer Lingus Cadet and British Airways Cadet Program are remarkable opportunity that transforms these dreams into reality, offering aspiring pilots a structured and comprehensive pathway to becoming esteemed aviation professionals.

This article dives into the details of the Aer Lingus and BA Cadet Programs, highlighting its distinctive features, benefits, and the exciting journey it offers those who aspire to navigate the vast expanse of the sky.

Aer Lingus Cadet Program

The first and most important thing: Hurry up! The deadline approaches: you can send your application till the 16/08/2023 by 17:00 GMT.

The cadet program offers intense and structured training (around 14 months) that covers all aspects of piloting. From theoretical classroom instruction to hands-on flight experience, cadets undergo a thorough training regimen that prepares them for the challenges of the aviation industry. The training is held at the famous FTE Jerez, in southern Spain. Successful candidates will be offered a Type Rating (which lasts about 12 weeks) on the most used plane in Europe: Airbus A320, and the base will be obviously Dublin.

The minimum and educational criteria are listed in the offer. There is also a comprehensive Q&A that answers the most asked question and a friendly welcome video about the airline’s new livery. According to the cadet website, the ideal cadet “will need to possess excellent communication, problem-solving and teamwork skills, as well as an appreciation of the service our customers expect.” The course is totally bonded from the airline, which means there will be a bond to cover the cost of the training and other associated costs, and for a period after the cadet commences as a First Officer.

BA Cadet Program: The Speedbird Pilot Academy

Unlikely the Aer Lingus one, for this cadet program, you do not need to be in a rush since the applications are currently still closed and will open in September 2023. It’s anyway worth having a look at the conditions and requirements; as September approaches, British is setting the maximum number of cadets: 60. If you wanna be part of the lucky (and skilled) “60”, have a look at the minimum requirements and don’t miss the deadline application. The strictest requirement of British Airways is the language: the airline is asking the candidate to obtain an ICAO 6 in the English language.

The ICAO Aviation Language certificate can be obtained directly with the CAA or through a recognized and authorized language school. The ICAO 6 certificate is particularly useful since it has no expiration date (unlikely ICAO4 and 5, which last respectively 4 and 5 years).

The training with BA will last about 18 months, and exactly as for the Aer Lingus Cadet Program, it’s fully funded by the airline. For more questions, on the 22nd of August, BA will be running a live Q&A session between 12 and 13 (UK Time). More info and the link to join the call are here: Come and Meet us (ba.com)

Are you dreaming of becoming a pilot, but you never had a chance due to economic problems or lack of motivation? Well, this is your chance! Apply and give your best to realize your dream!

Informative

Flag Carriers as a Symbol of Honor: Between Past and Present

Published

1 month ago

11/08/2023

Mai Adel

Most of the world’s countries have their flag carriers for financial and national duties. A flag carrier is considered an international representative of a country as it stands as a symbol of pride. Therefore, some passengers are keen to ride the flag carrier of their countries as it reflects their identity. However, what is the history of flag carriers?

History of Flag Carriers:

The term “flag carrier” emerged when countries established state-owned airline companies. However, because of the high cost of running such companies, the governments took the initiative to support these companies financially. At this time, there were many airline companies entirely owned by governments. However, a flag carrier can be subsidized or owned by the country, and it has preferential rights or privileges by the government for international operations. In the innovation industry, flag carriers have both financial and symbolic importance. Thus, most countries of the world have their flag carriers.

Countries have Flag Carriers:

Most countries have their flag carriers representing their identity and nationalism worldwide. Examples of these flag carriers are:

Air France

Egyptair
Oman Air

Qatar Airways

However, nowadays, it is not conditionally an airline owned or subsidized by a country. The literal meaning of a flag carrier is an airline carrying its country’s flag worldwide. Now, it can be an airline the country supports to be its flag carrier. For example, the British Kingdom does not own British Airways, but it carries the British flag all over the world. The people recognize it as the British flag carrier. However, some countries do not have a flag carrier but have two, like the United Arab Emirates, but why?

The UAE Has Two Flag Carriers:

If a flag carrier is a symbol of identity and pride, does having two change the equation? The answer to this question is that it does not change the equation this much, but it is more like meeting the country’s needs. Having a two-flag carrier is normal for a country, such as the UAE, in this geopolitical situation. The two Flag carriers are Emirates, the first flag carrier based in Dubai, and Etihad Airways, the second flag carrier based in Abu Dhabi. The royal family established both airlines. Though the UAE has two flag carriers, some of the countries do not have any, such as the US, but why?

The US has no Flag Carrier:

It is true that now the United States of America has no flag carrier, but this has not been the case in the past. In the past, the US had Pan Am, the unofficial US flag carrier in the 20th century. However, running an airline costs a lot. Pan Am could not stand the market and went bankrupt in 1991. Since then, the US has not had a flag carrier, though it has major international airlines, such as American Airlines. Regardless of the current situation of the flag carriers, what are the expectations for their future?

The Future of Flag Carriers:

As we live in the era of technology, predicting the future of something is not a wise move. However, the competition in the aviation market is so fierce, and running an airline company is not a joke. Seeking honor and pride in running an airline is great. However, the competition in the market knows nothing about honor and pride. Maybe, some of the flag carriers will prosper, and some of them will vanish. This thing only time can tell.

Informative

Flying Cars: The Future of Transportation?

Published

2 months ago

08/08/2023

Ahmed Adel

Flying cars have been a dream of science fiction writers for decades, but they are now becoming a reality. Many companies are working on developing these cars, and some of them are already making significant progress.

What are flying cars?

Flying cars are vehicles that can take off and land vertically, like a helicopter. They are also capable of flying horizontally, like an airplane. This makes them a versatile form of transportation that can be used for both personal and commercial purposes.

There are two main types of these cars: eVTOLs (electric vertical takeoff and landing vehicles) and tilt rotors. eVTOLs use electric motors to power their rotors, while tilt rotors use a combination of electric motors and propellers.

The different types of flying cars

There are many different types of flying cars being developed, each with its own unique features and capabilities. Here are a few examples:

PAL-V Liberty: The PAL-V Liberty is a tilt-rotor that is currently in development. It has a top speed of 160 mph and a range of 100 miles.

AeroMobil 3.0: AeroMobil 3.0 is another tilt rotor that is currently in development. It has a top speed of 200 mph and a range of 435 miles.

eVTOL Volocopter: The eVTOL Volocopter is an electric vertical takeoff and landing (eVTOL) that is currently in development. It has a top speed of 62 mph and a range of 22 miles.

SkyDrive SD-03: The SkyDrive SD-03 is an eVTOL that is currently in development. It has a top speed of 50 mph and a range of 62 miles.

The challenges of the developing

There are a number of challenges that need to be overcome before these cars become mainstream. One challenge is safety. Flying cars need to be extremely safe in order to be approved for public use. Another challenge is regulation. Governments must develop new regulations for flying cars before they can be flown in our airspace.

The Potential Impact

If successful, flying cars could revolutionize commuting, travel, and logistics by making those activities faster, easier, and more flexible. Their future impact depends on overcoming hurdles related to safety, cost, and regulations. With progress in those areas, flying cars could become commonplace in the next few decades, fundamentally changing transportation.

The Future of Flying Cars

The transition to flying vehicles holds great potential for improving mobility. While still a developing technology, continued progress by companies working on these cars indicates they may ultimately transform how we move about and deliver goods.

“Flying cars are the future of transportation. They’re faster, more convenient, and more environmentally friendly than cars or airplanes.” – Elon Musk