GK Question “How The Engine of Jet Works?” general knowledge book English 2021 current affairs quiz and answers for class 7, 8

How The Engine of Jet Works?

We know jet engine’s power is the newest and this powers the most powerful and latest aircraft we have today. The principle behind this was discovered about 2,000 years ago! The principle is jet propulsion and was first shown by the Greek mathematician, Hero of Alexander, in about 120 B.C. He used the force of steam escaping from a heated metal ball to spin the ball like a wheel.

We show, how jet propulsion works. Let us consider an ordinary blown-up balloon. When we close the mouth of the balloon the air inside pushed in all directions with uniform force. With the opening of the mouth, the pressure of air is lessened and air rushes out. However, at the top of the balloon, the point opposite the mouth, the air pushes with greater pressure. The balloon moves in the direction of the greatest pressure, which is forward. So it is not the exhaust but the forward push, which causes the balloon to move.

This is because there is a law of motion to every action, there is an equal and opposite reaction. In a jet engine, the “action” is the exhaust’s backward push, while the equal and opposite “reaction” is the forward thrust.

There are two types of jet engines. There are ramjets and turbojets. The ramjet is like a flying stovepipe. It does not have any moving parts. Air is forced into the front opening, called “the intake”, by its own forward motion. The air is mixed with fuel and gets burnt; increasing the gas to five times in volume. This is then exhausted at the tail end which is smaller. The fire in the ramjet creates no push when standing still, but the power is produced.

On contrary, in a turbojet, the air is sucked in by a compressor. It is then compressed and forced into the combustion chamber, where it is mixed with fuel and burnt. The hot expanded gases go through a turbine and then escape through the exhaust nozzle, producing get thrust. If the energy is delivered to the turbine, and the turbine shaft is made to turn the propeller of the airplane. We have a jet engine that is called a “turboprop”.