How a Jet Engine Works: Explained with Diagrams and Real-Life Examples [2025 Guide]

From commercial airplanes cruising at 35,000 feet to fighter jets breaking the sound barrier, jet engines are the beating hearts of modern aviation. But have you ever wondered how these engineering marvels actually work?

In this guide, we’ll break down the working of a jet engine into simple parts, explain the science behind thrust, showcase real-world applications, and even peek into the future of propulsion — from hydrogen-powered to electric hybrid jet engines.

🚀 What Is a Jet Engine?

A jet engine is a type of reaction engine that generates thrust by expelling high-speed exhaust gases. Unlike piston engines, which rotate a shaft, a jet engine creates linear force (thrust) to push aircraft forward.

Used In:

• Commercial airliners (Boeing, Airbus)
• Military aircraft and drones
• Space applications (combined with rockets)

🛠️ Types of Jet Engines

Did You Know? The GE9X, used in Boeing 777X, is the world’s largest and most powerful turbofan engine.

🔍 The Basic Principle: Newton’s Third Law

Jet engines work based on Newton’s Third Law:

“For every action, there is an equal and opposite reaction.”

As the engine pushes air and exhaust gases backward, the aircraft is propelled forward with equal force — this is called thrust.

⚙️ Jet Engine Parts and Working

Main Parts of a Jet Engine:

1. Intake
2. Compressor
3. Combustion Chamber
4. Turbine
5. Nozzle

Working Process:

Air In → [Intake] → [Compressor] → [Combustion Chamber] → [Turbine] → [Nozzle] → Jet Out

Step-by-Step Breakdown:

1. Intake

Air enters the intake as the plane moves forward. It's smoothed and slowed slightly to prepare it for compression.

2. Compressor

The air is compressed using rotating blades. This increases its pressure and temperature significantly, often by 30x or more.

3. Combustion Chamber

Fuel is injected and ignited in the compressed air. The result: a continuous explosion that rapidly heats and expands the air.

4. Turbine

Some of this hot air spins the turbine blades, which are connected to the compressor — powering it in return.

5. Nozzle

The remaining hot gases are expelled through a narrowing nozzle, accelerating them and generating thrust.

📈 Physics of Thrust

Thrust Equation:

Thrust (F) = ṁ × (Vexit - Vinlet)

Where:

• ṁ = mass flow rate
• V_exit = exhaust speed
• V_inlet = intake air speed

The greater the speed difference, the more thrust is produced.

✈️ Real Jet Engines in Action

⚙️ Jet Engine Innovations in 2025

1. Hybrid-Electric Engines

These engines combine electric motors with fuel burners to improve fuel efficiency and reduce emissions.

2. Hydrogen-Powered Jets

Liquid hydrogen replaces fossil fuels. It burns clean but requires special cooling systems.

3. Scramjets

Air-breathing engines with no moving parts — used in hypersonic research and future spaceplanes.

📚 Frequently Asked Questions

What fuel do jet engines use?

Mostly Jet-A1 (aviation kerosene); military versions may use JP-8 or alternatives.

How hot does it get inside?

Temperatures can reach over 2,000°C (3,600°F) inside the combustion chamber.

Can jet engines run in space?

No — jet engines need atmospheric oxygen. Spacecraft use rockets instead.

Are jet engines loud?

Yes, due to high-speed exhaust turbulence and supersonic fan blade tips.

How are they started?

Via an APU (auxiliary power unit) or external ground systems that spin the turbine initially.

🧠 Conclusion

From intake to nozzle, every part of a jet engine plays a role in pushing humanity forward — literally. Whether it’s a quiet turbofan powering your next flight or an experimental scramjet breaking hypersonic barriers, the **jet engine remains one of the greatest inventions of all time**.

As we look ahead to cleaner skies with hydrogen and electric aircraft, it’s clear: the future of propulsion is exciting, fast, and smarter than ever.

💬 Got Questions?

Leave a comment below or check out our next article on “Future of Hydrogen Jet Propulsion in India.”