In this article, we will learn the basics of jet engines along with working, parts, diagrams, applications, etc. Also, we will explore how does a jet engine work. Let’s explore the jet engine and it’s working!
What are Jet Engines? Definition
Jet Engines Basics
Let’s start with the basics of Jet Engines! There are some of the box inventions that have defined the course of time. These inventions established humankind at the top of the hierarchy. One of the most valuable and extravagant inventions is the Jet engine.
- Jet propulsion mechanism was in pipeline way before any of the jet planes was manufactures.
- The first idea for anything related to jet engines came in 150BC when n Egyptian philosopher names Hero has a mere concept of a cauldron-shaped machine that converts steam pressure into a jet force.
- It was called Aerophile.
After that, 300 years ago, the law of motion helped humankind to develop the concept of jet propulsion. It runs on one of the most popular physics laws, which says that “for every action, there is an equal and opposite reaction.”
When was the Jet Engine Invented?
This was first used in a horseless vehicle which was known as the Newton Steam engine. This vehicle uses jet propulsion to move from one space to another.
The history of the development of the jet engine attained its core position in 1928 when the first practical idea was generated, which entails that these engines can be used in aircraft. After that, these ideas came into the practical world and made it quite real. The idea of the jet engine flourished after 1930. Here, we will discuss one of the most critical inventions that has evolved humanity to move with great pace and air.
- These are the achievements that make humankind explore new heights.
- Whether it is the battlefield or a way to reach one place to another, the jet engine has been quite an important discovery.
- We will provide all the information right from the historical importance to the applications and different jet engines.
- This will not only help us to get a broader perspective but will also help us in changing perspective.
Let’s start with the general introduction of the Jet Engines.
Concept of Jet Engines Working & Schematic Diagram
Jet engines are the machine that helps the airplane to move forward with excessive force. A massive thrust generates this force. This thrust helps the plane to fly at a maximum pace. Jet engines are also known as gas turbines that work on the principle as same as the turbines.
- In this, the engine sucks air in at the front end of the fan.
- In this, the compressor helps to increase the pressure of the air. The compressor is manufactured with numerous blades that are connected to a shaft.
- In this, the blades are capable of spinning at maximum speed, which squeezes the air. Gradually the squeezed or compressed air is being ignited with the effect of fuel and electric spark.
- The engine and the aircraft move forward with the excessive thrust generated due to the gas shooting backward.
- The hot air passes through the nozzle, which also gets through a set of blades known as a turbine.
- The turbine is connected with the same shaft as same as the compressor.
While understanding jet engines, it is quite important to get an idea about the phenomenon that makes the core engine efficient. It is known as thrust.
Let’s get an understanding about the same.
Thrust is nothing but the excessive forward force that helps push the engine, which ultimately helps the aircraft move forward. As per Newton’s third law of motion, every action has an equal and opposite reaction. A jet engine uses this principle.
- In this, a massive amount of air is taken inside.
- The air gets heated and compressed and also being slowed down for the motion.
- This air helps in the spinning of the blades of the fan. Gradually the mixture of fuel and compressed air is being ignited by an electric spark.
- The temperature can rise to 3000 degrees Celsius.
- The power generated is then used for turning the turbine.
- After this, when the air leaves, it provides a backward push out of the engine. Ultimately, the plane moves forward with the help of the thrust generated.
Parts of Jet Engines & Diagram
The jet engine is equipped with some of the essential parts that define the whole working of the same. These are quite important and lead the actual working of the same.
However, some of the subsidiary parts are also present in the jet engines, which we will describe briefly in the further write-up. It starts with the main parts, which are quite important.
This is the first part of the turbofan. These are quite large and suck a massive quantity of air.
- The blades of these fans are manufactured of Titanium. These fans’ core working is associated with speeding the thin air up and splitting them into two parts.
- These parts work as one of the parts flows through the engine’s core, where it affects the other engine components, while the other part bypasses the engine’s core.
- It moves through a duct which is surrounding the core to the back of the engine.
This is one of the parts that are quite important in the engine core. It is made up of fans with numerous blades.
- These are attached with a shaft.
- The compressor is responsible for squeezing the air that enters tiny areas that ultimately increase the air pressure.
- It helps increase the potential energy of the air.
- The compressed air is forced into the combustion chamber, which makes it quite effective.
This is one of the essential parts of a jet engine in which air is mixed with fuel, and then ignition gets into the vicinity.
- In this, there are numerous nozzles available for spraying the fuel into the airstream.
- The fire then gets ignited with a mixture of fuel and air. Due to this, it acquires high temperature and optimal energy airflow.
- The fuel then burns gradually with the oxygen present in the compressed air.
- The inner core of the combustor is generally made up of ceramics that help it acquire the property of heat resistant chamber.
- Inside the combustor, the heat can easily reach up to 2500 degrees Celsius.
This is the part that is attached to the combustor. The high energy inflow goes into the turbine from the combustor, which ultimately helps rotate the turbine blades.
- The turbines are attached by a shaft that helps in turning the blade in the compressor. It also helps in spinning the intake fan.
- The gases that accumulate in the combustion chamber move through the turbine and helps the blades to rotate.
- The redundancy in spinning is numerous for the turbine; it is attached with numerous sets of the ball bearing to cater to this.
The nozzle acts as an exhaust duct of the engine. This is among the most efficient part of the engine that produces the thrust for the plane.
- In this, the energy which doesn’t come into play passes through the turbine.
- Following that, the colder sir that bypassed the engine core generates a force while exiting the nozzle that helps in propelling the engine.
- With this mechanism, the airplane moves forward.
The above are some of the core parts of the jet engine that play an important role in functioning. Apart from these, numerous subsidiary parts are equally important for the proper functionality. The following are that subsidiary yet important parts of the jet engine:
This is the part of a jet engine that doubles the power of a jet engine. The fuel is sprayed in the exhaust duct and mixed with the hot air due to the engine’s blowback features. After all of this, it is ignited, which provides a powerful blow.
This is the part used on a piston engine that helps mix the fuel and air appropriately. After this only, it drives to the engine for further ignition.
It is the section of the jet engine that is equipped with high pressure. It is also equipped with a high-pressure compressor, turbine, and combustion chamber.
This is more of housing that surrounds the engine.
This is the part of the jet engine responsible for holding the rotating blades of the jet engine.
This is the exhaust which has a tube-like structure joint at the rear end of the engine that is mainly responsible for the discharging of hot air of the jet.
The main function of the generator is to produce electrical power for the airplane.
The igniter is the jet engine component used to ignite the mixture of compressed air and fuel when they enter the combustion chamber. This is among the vital parts of the jet engine, which makes it quite efficient.
Pylon is a jointer that is of metal structure which helps in connecting the engine to the wing.
This is one of the compressor components used to attach the turbine blade to the disc.
How Does a Jet Engine Work?
Understanding the core working of a jet engine is quite complicated, but it can be simplified with some of the basic terminologies. Certain functionalities can easily describe the same.
A basic jet engine air specifically enters the front intake and gets compressed to the optimal extent. After this, the air is forced to enter the combustion chamber where fuel is being sprayed, and the ignition process is started.
- The gases formed are expanded rapidly, and the exhaust process comes into play through the rear of the combustion chambers.
- With the exertion of these gases, an equal amount of force is dislodged in every direction, which ultimately provides forward thrust while attaining exertion.
- When the gases leave the engine, they pass through a turbine setup which helps in rotating the shaft.
- It rotates the compressor, which brings a fresh supply of air.
The process of working can be described with four phenomena, which are quite easy to understand. The process of working is equipped with four steps that create the thrust for a jet engine. The four processes are as follows:
These processes while listening seem so unusual, but the whole process of working depends on these. Let’s delve into the brief explanation of the following:
Jet Engine Working Step#1: Suck
This is when the engine sucks a massive air volume through the compressor stages and fan.
- A normal commercial jet engine generally takes 1.2 tons of air per second during takeoff, which generated ample thrust.
- The whole mechanism through which the jet engine sucks the air is massively a part of the compression stage.
In most engines, the compressor is responsible for both sucking and compressing the air. This mechanism is the first one among the four, which is quite essential and effectively helps start the whole mechanism of the jet engine.
Jet Engine Working Step#2: Squeeze
Just after drawing air into the engine, there is one process that provides the massive force.
- In this, the compressor pressurizes the air that helps it to get toward the combustion chamber.
- The compression fans function from the turbine through a shaft. In this, the compressor is capable of achieving compression ratios of 40:1.
- With the help of this, a typical jet compressor rotates at 1000mph and can easily take 1200kg of air per second.
This is one of the mechanisms that define the core working.
Jet Engine Working Step#3: Bang
The bang is the name given to this mechanism as there is the ignition in the combustion chamber in which air and fuel mixture gets ignited.
- This bang is specifically the cause for the expansion that forces the air inside the turbine.
- In the combustion chamber, the fuel burns at temperatures more than 2000 degrees Celsius.
- This is the temperature where metals also get on at the melting.
- In this section, advanced cooling techniques are used, which makes it withstand the temperature.
In this mechanism, the combustion chambers play a vital role in which the burning of large quantities of fuel occurs. The fuel is supplied through the fuel spray nozzles, which are equipped with a massive air volume.
- This air is supplied by the compressor and released the resulting heat, which ultimately produces thrust.
- Bang is one of the tasks in a jet engine that should be achieved with minimal loss of pressure and with maximum heat in a small space area.
In the Jet Engine, this is the accessory that helps to acquire most of the thrust that is needed for the forward push of aircraft. In this, there are some of the processes that make it quite efficient. The amount of fuel added to the air is dependent upon the temperature required.
It is achieved through different accessories and compressors. The combustion chamber has an important role in this as it should be capable of withstanding that kind of temperature, maintaining stability, and providing maximum efficient combustion under any engine conditions.
Jet Engine Working Step#4: Blow
This is the last mechanism through which the whole engine ultimately acquires the thrust needed.
- In the reaction of the expanded gas with the mixture of air and fuel is forcefully moved through the turbine and drives the fan.
- After this, it blows out the exhaust nozzle that helps in acquiring the much-needed thrust.
- Here we can deduce that the turbine has the core functionality of equipping the compressor and accessories with much-needed power.
- The whole process is attained by generating energy from hot gases.
These hot gases are released from the combustion system, and at a lower pressure and temperature, it gets expanded. Here for producing ample torque, the turbine needs several stages of mechanism. In this, the blades and stationary guide vanes play a prominent role. The different stages critically depend on the connection between the rotational speed and the power needed from the gas flow, and the size of the turbine, specifically its dimension.
This last but not the least mechanism of the four bits of help produces high efficiency of power. Though there are some concerns,
- The turbine blades are expected to withstand excessive temperature and redundant operation.
- Sometimes the blade of the turbine glows as red hot.
To cater to this problem, the turbine should be strong enough to withstand the critical temperature and continuous operation for a long time. For this, numerous innovations are available in which the blades are equipped with small holes that help cool the air. These turbine blades are manufactured with Nickel alloys as these materials can withstand high temperatures.
Types of Jet Engines with Diagrams
There are different kinds of Jet engines available and known by different names. Some of them are described below;
This is one of the popular jet engines that are based upon simple principles.
- The air is taken in from an opening that is present in the front of the engine.
- In this, the air gets compressed to 4 to 12 times its original pressure.
- The holistic work for compressing depends upon the compressor.
- The fuel is added, and the mixture is ignited in the combustion chamber at a high temperature.
- The turbojets are more of a reaction engine in which the expansion of gases comes into play.
- The turbojet also works on the principle of sucking and squeezing gases.
- In this, the gases flow through the turbine and spin it.
The gases bounce back and come out with great force from the exhaust nozzle, which ultimately pushed the aircraft forward.
Application: The core use of turbojets is in those aircraft that need maximum speed. It is massively used in fighting jets and other kinds of aircraft with the basic need for massive speed.
Turboprop Jet Engines
Turboprops are the jet engine that is connected to a propeller. In this, the turbine is present at the back.
- This turbine gets into motion when the hot gases come through it, ultimately driving the propeller attached to a shaft.
- Turboprops are also equipped with compressors, turbines, combustion chambers.
- In this, the gas and air pressure are used to run the turbine.
- The turboprops jet engines have comparatively more efficiency for those aircraft that need below 600miles per hour.
However, some modern turboprops are equipped with numerous advancements, such as propellers with smaller diameters. It also has numerous blades that are pretty important for providing maximum efficiency.
Application: The core application of turboprops is in airliners as well as transport aircraft.
Turboshaft Jet Engines
Turboshafts are the kind of gas turbine engine which is not for driving a propeller.
- The turboshafts are specifically designed to provide power to the rotor shaft, which remains independent of the rotating speed of the gas generator.
- This helps in keeping the speed of the rotor constant at different speeds.
- The modulation also not the effect is the power provided to the generator.
Application: The core use of turboshafts is to provide power to a helicopter rotor.
Ramjets are the most common jet engine and very simpler ones that are equipped with zero moving parts.
- In this, the air compresses into the engine with the help of the speed of the jet.
- It is specifically a turbojet in which rotational machinery has been detached.
- In this Jet engine, the application is confined to the compression ratio, which also depends upon forwarding speed.
- The ramjet is capable of developing minimal thrust.
- It is used for guided missiles and where there is a need for assisted takeoff.
Application: Ramjets are used explicitly for guided missiles as well as in space vehicles.
With the help of different mechanisms, the above analysis makes our understanding of Jet Engine quite clear. With the help of the suck-squeeze-bang-blow mechanism, it is pretty easy to understand the whole work. Not only the outer information but also the different parts and kinds make it quite compelling. However, the Jet engine is one of the topics that needs massive analysis as some different phenomena and mechanisms need specific elaboration.
This article has started with a general introduction of the Jet engine with all the historical development associated. Following that, we have also provided four simpler mechanisms that help in understanding the core working. Last but not least, the different kinds of Jet engines make this excerpt quite interesting with ample information.