Beginning of the Jet Age
The heralding of the jet age which began with the invention of the jet engine in the 20th Century was a giant leap for science. Before the jet engine was developed, aircraft were run with conventional piston engines. In fact, way back in 1903, Wilbur and Orville Wright – known as the famous Wright Brothers put in a piston-based engine made from aluminum in their maiden airplane, the Wright Flyer. This process continued till the 1930s when aeronautical designers were of the opinion that aircraft speed could not perhaps be increased anymore because a piston engine was powerful enough to spin an aircraft’s propeller any faster.
It was also during this period that two men were thinking differently. They had dedicated their research to the development of an engine that would have increased speed and power. Frank Whittle and Dr. Hans von Ohain are officially recognized and accepted as the joint fathers and inventors of the jet engine, also called a turbojet engine.
27th August 1939 is a historical day in the field of aeronautics as Dr. von Ohain successfully piloted the first aircraft to be powered by the turbojet engine. It was called the Heinkel HeS 3B Turbojet.
A New Chapter Begins:
Towards the end of the Second World War, the Heinkel HeS 3B Turbojet found use in the much dreaded Messerschmidtt ME 262 A aircraft used by the German Luftwaffe or air force during the Blitzkreig on Allied territory. The Messerschmidtt incidentally was the first jet aircraft to be used in combat.
New Developments in Jet Engines:
Over the last few decades, advances in aeronautical technology has led to the creation of three jet engine types: the turbojet, turbofan engine and turboprop engine. These are somewhat similar to the erstwhile piston engines, but definitely more complex in structure. In piston engines, the aero fuel burned to mobilize the pistons by way of a four-stroke cycle. In a jet, the power is generated by turbine blades that are constantly spinning. In order to spin these turbine blades, a constant supply of air and burning fuel are required.
Workings of a Jet Engine:
The turbojet engine comes with a combustion chamber, compressor and one turbine, which produced a thrust from the engine’s rear. The thrust required to power the aircraft requires air to pass through the compressor and burn along with the fuel present in the engine’s combustion chamber to operate the turbine. However, the turbojet engine is relatively simpler and somewhat inefficient as compared to the turboprop engine.
The Turbofan engine on the other hand, has a powerful fan fixed to the engine’s front. The engine also has a compressor, combustion chamber or combustor as also a turbine that is found in the turbojet engine. The state-of-the-art turbofan engine has 2 compressors at the engine front. The first compressor is called the booster while the second is a high-pressure compressor. This engine is also equipped with 2 turbines at the engine’s rear, with the first turbine being a high-pressure one while the second is of the low-pressure type.
The turbofan engine’s fan forces air circulation around the engine’s main part which provides an additional thrust. It cools the engine also while reducing its noise as well. Today, these have found extensive use in modern commercial aircraft and save fuel while also reducing flight costs.
The Turboprop comes with an external propeller. The air and fuel burn in its combustor, the turbine rotates, which in turn drives propeller rotation. An additional component is the reduction gear which translates the turbine rotation to the propeller’s required rotation speed. A turboprop aircraft flies most efficiently between the altitudes of 20,000 — 30,000 feet.
The jet engine has revolutionized global transportation by reducing time spans to the bare minimum. The Concorde for example, with its supersonic speed reduced flight time between New York and London by almost 75%, an unthinkable feat in the pre-War era. Even though the jet age began 78 years ago, it’s here to stay. And it will surely conquer the world more and more in the years ahead.