When combined with these aerodynamic principles, thrust from an engine is enough to allow an airplane to take off and fly. Without them, no matter how powerful an engine is, a plane would not be able to get off the ground. The combination of the thrust, lift, and drag makes it possible for planes to soar through the sky.

By understanding these principles of aerodynamics and applying them correctly, engineers have been able to design aircraft that can fly faster, further, and higher than ever before. From the Wright Brothers’ first flight over 120 years ago to modern passenger jets and unmanned drones, these principles of aerodynamics have made it possible for aircraft to soar above the clouds.

How have airplanes changed in the last 100 years?

The last hundred years have seen an incredible transformation in the shape, size, and capabilities of airplanes. Early biplanes had open cockpits and were made almost entirely of wood, canvas, and wire. While these planes may have been primitive compared to those of today, they were still capable of flying up to speeds of about 12 mph!

Fast forward to the present day, and modern airplanes are incredibly sophisticated machines that are capable of carrying hundreds of passengers at speeds upwards of 500 mph. The use of advanced materials such as aluminum, composites, and titanium in airplane construction has allowed for significantly lighter, faster aircraft with increased durability.

Today’s planes also feature state-of-the-art navigation and safety systems, as well as improved engines that are more fuel efficient and powerful. Advances in avionics have allowed pilots to fly higher, faster, and farther than ever before, while digital flight controls provide a smooth and comfortable ride for passengers.

Modern models are designed for different types of purposes such as cargo transportation, passenger travel, military operations, surveillance, and emergency services. Over the years, airlines have adopted new technologies to make their aircraft safer and more reliable. Advances in aeronautical engineering have resulted in airplanes with greater speed, range, efficiency, and comfort for passengers. They are much lighter than before thanks to advances in materials technology such as carbon fiber composites. These materials are strong and light, reducing fuel consumption and increasing the range of the aircraft. Automation has also made flying safer with features such as autopilot and self-diagnosing systems that reduce human error.

The improvements in aircraft technology have also had a major impact on the environmental footprint of air travel. Aircraft engines are now more fuel efficient, allowing for longer distances to be traveled with fewer emissions. Additionally, modern planes are designed to make minimal noise and reduce the amount of turbulence experienced by passengers. Advances in materials technology has also enabled aircraft manufacturers to develop lighter frames that are more resistant to corrosion , allowing for more efficient and longer-lasting aircraft.

The advances in aircraft design over the last century have been nothing short of remarkable. In addition to improved speed and performance, modern airplanes are now equipped with more efficient engines and navigation systems. Automation has removed much of the manual labor required for piloting, resulting in safer and more reliable aircraft. Materials technology has enabled manufacturers to create lighter frames that are less prone to corrosion and wear-and -tear. These advancements have made air travel more efficient, cost effective, and environmentally friendly than ever before.

Overall, the last hundred years have seen a dramatic evolution of the modern airplane, from an open-cockpit biplane to a highly sophisticated and efficient machine. With these advances in technology, it is clear that the sky truly is the limit for aviation!

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Quite familiar words for many people. However, people who understand well know that in fact all these “sound” epithets often describe the work of jet engines as a whole or its parts, having very little to do with turbines, as such (except, of course, the mutual influence in their joint work in the overall cycle of turbofans).

Moreover, in a turbojet engine (just such are the object of enthusiastic reviews), as a direct reaction engine, which creates thrust by using the reaction of the gas jet, the turbine is only part of it and to the “roaring roar” has rather indirect relation.

On those engines, where it, as a unit, plays, in some way, the leading role (these are indirect reaction engines, and they are not called gas turbines for nothing), there is no such impressive sound, or it is created by completely different parts of the power plant of the aircraft, for example, the propeller.

That is, neither the hum nor the rumble, as such, are actually related to the aircraft turbine. However, despite such sound inefficiency, it is a complex and very important unit of a modern turbine, which often determines its main performance characteristics. No GTE can do without a turbine, simply by definition.

History and Theory

And even a very long time ago. Since the time when mechanisms were invented that converted the energy of the forces of nature into useful action. The simplest in this respect and therefore one of the first to appear were the so-called rotary engines.

This definition itself, of course, appeared only in our days. However, its meaning just defines the simplicity of the engine. Natural energy directly, without any intermediate devices is converted into mechanical power of rotational motion of the main power element of such an engine – the shaft.

The turbine is a typical representative of the rotary engine. Getting ahead, we can say that, for example, in a piston internal combustion engine (ICE), the main element is the piston. It performs reciprocating motion, and to obtain the rotation of the output shaft, it is necessary to have an additional crank mechanism, which, naturally, complicates and weighs down the design. The turbine is much more advantageous in this regard.

For the rotary-type ICE, as a heat engine, which, by the way, is a turbojet engine, the name “rotary” is usually used.

Some of the best known and oldest applications of the turbine are large mechanical mills, used by man since time immemorial for various economic needs (not only for grinding grain). These include both water and wind mechanisms.

For a long period of ancient history (the first mentions from about the 2nd century B.C.) and the history of the Middle Ages, these were actually the only mechanisms used by man for practical purposes. Possibility of their application with all primitiveness of technical circumstances was in simplicity of transformation of energy of used working body (water, air).

In these, as a matter of fact, real rotary engines the energy of water or air flow is converted into power at the shaft and, eventually, into useful work. This happens when the flow interacts with the working surfaces, which are blades of a water wheel or wings of a windmill. Both of them, in fact, are the prototype of blades of modern blading machines, which are turbines used nowadays (and compressors, too, by the way).

There is another type of turbine, first documented mentioned (apparently invented) by the ancient Greek scientist, mechanic, mathematician and naturalist Heron the Alexandrian (Heron ho Alexandreus, 1st century AD) in his treatise “Pneumatics”. The invention he described was called the aeolipile, which in Greek means “ball of Aeolus” (the god of wind, Αἴολος – Aeolus (Greek), pila – ball (Latin)).

In it, the ball was equipped with two oppositely directed nozzle tubes. Steam came out of the nozzles and entered the ball through the pipes from the boiler located below and thus made the ball rotate. The action is clear from the figure above. It was a so-called inverted turbine, rotating in the opposite direction to the steam outlet. Turbines of this type have a special name – jet turbines (more details below).

It is interesting that Heron himself hardly had any idea what the working body of his machine was. At that time, steam was identified with air; even its name testifies to this, because Aeolus commands the wind, that is, the air.

The Aeolipile was, in general, a full-fledged thermal machine, which converted the energy of the burned fuel into the mechanical energy of rotation on the shaft. It was probably one of the first thermal machines in history. However, its usefulness was still “incomplete”, because the invention did not perform any useful work.

The Aeolipile, among other mechanisms known at that time, was part of the set of the so-called “automata theater”, which had great popularity in the following centuries, and was actually just an interesting toy with an unclear future.

From the moment of its creation and in general from the era when people in their first mechanisms used only “manifestly manifest” forces of nature (wind power or gravity of falling water) to the beginning of confident use of thermal energy of fuel in the newly created thermal machines passed not one hundred years.

The first such machines were steam engines. Real working examples were invented and built in England only by the end of the 17th century and were used for pumping water out of coal mines. Later, steam machines with a piston mechanism appeared.

In the future, as technical knowledge developed, piston internal combustion engines of various designs, more perfect and more efficient mechanisms, “came on the scene”. They already used gas (combustion products) as a working body and did not require cumbersome steam boilers for its heating.

Turbines, as the main units of heat machines, also passed a similar path in their development. Although there are separate mentions of some specimens in history, but noteworthy and documented, including patented, units appeared only in the second half of the 19th century.

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Each of these units has its own specific application area. It basically depends on the specific purpose of the engine, and, as a consequence, the aircraft. Modern output devices often combine different functions and can therefore be quite complex designs.

However, despite the variety, some of these functions can in a sense be called secondary (noise attenuation, for example, or visibility reduction). To the main ones for GTEs of direct reaction initially belonged the possibilities of forming the necessary parameters of the gas flow, coming out of the engine.

In this sense, the output devices can be divided into two groups. The first, by shaping the flow, makes its output pulse as large as possible and directs it in the desired direction. The second one does the opposite, i.e. turns the flow into a simple “exhaust”.

The first group are jet nozzles, the second group are diffusers and various kinds of exhaust pipes. If the name (and hence the purpose) of the engine contains the word “jet”, then the obligatory element of the output device will be a jet nozzle. In our case, these are different types of air-jet engines. Of course, in each of them, the nozzle has its own specific type and level of complexity of design.

It is worth noting separately that an important function of the nozzle is also to provide the possibility of stable joint operation of the elements of the GTE in the main modes. The size of the passage section of the nozzle affects the temperature of the flow, so it can be a factor in regulating the operation of the engine. Especially, if the nozzle is structurally able to change the area of the passage section.

A gas turbine engine, as a dynamic expansion machine, uses the disposable energy of the gas (which it has gained by heating and increasing pressure) to do work on the turbine. The gas expands in it, accelerating in the nozzles and rotating its impellers.

The resulting power is used to rotate the compressor and the so-called payload units. If actuating these units is the main function of the engine, as is the case, for example, in TvAD, then it is designed so that almost all the available energy of the gas (or most of it) is converted into mechanical work. Unless, of course, the engine is structurally perfect enough and is not engaged in “pumping” energetically charged gas into the atmosphere.

That’s why a helicopter gas turbine engine (turboshaft) usually has a diffuser gas outlet as an output device. The gas flow coming out of the turbine of such engine has already spent the vast majority of its disposable energy to rotate the main rotor, transmission and of course its own compressor.

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Classification

Aircraft engines, by the method of creating thrust are divided into three groups: propeller; jet; combined.

Propeller aircraft engines – piston aircraft engines, which create thrust by rotating the propeller, as well as combined aircraft engines, provided that the thrust created by the propeller is more than 50% of the total (equivalent) engine thrust.

Jet aircraft engines are direct-reacting thermal engines that convert the energy of the fuel into the kinetic energy of the gas jet flowing out of the engine – causing a reaction force directly used as the driving force – the thrust. Two types of jet engines are used in aviation: air-jet engines (AIR), which use atmospheric air oxygen to burn the fuel; rocket engines (RD), which use oxidizer transported by the aircraft itself to burn the fuel.

Combined (mixed) aircraft engines – creating thrust, consisting of the reaction force of the flow of combustion products, flowing out of the engine, and the thrust created by conventional or special propeller (propeller fan). The main types of combined engines are: turboprop engines (TVD); double-circuit turbojet engines (DTRD); propeller-fan aircraft engines (PAF).

Turbojet, turboprop, twin-circuit and propeller-fan aircraft engines are united by a common name – gas-turbine aircraft engines (GTEs).

Aircraft engines have special requirements for reliability, specific power or thrust-to-weight ratio, specific fuel consumption, as well as for overall dimensions and shape.

Obsolete concepts of unrealized projects:

• Steam Aviation Engine

In service or in operation in the past:

• Piston aircraft engine
• Gas turbine engine
• Pulsejet engine
• Turboprop engine
• Turbofan engine
• Air-jet engine, Jet engine
• Rocket Engine

Promising concepts:

• Nuclear aircraft engine
• Aviation electric motor – has dominated aircraft modeling since the early 2000s. It has been widely used on UAVs since the mid-2000s. Light-engine manned airplanes with electric engines are being created.

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