#72 The invention of the jet engine
Hello, hope all of you are having a fantastic day so far 🙂
Here it is cooking hot with +35 and up the last 2,5 weeks 🙂 A little bit too hot for my Scandinavian body to take 🙂
Anyhow lets not complain in my home country they have had 3 big floods and rain almost for the last couple of months. So I guess never complain since someone always has it worse than you 🙂
Today I wanted to give my thanks to a great invention of the last century. It really propelled anything in transportation to a easy to travel and very accessible world to most of us.
The jet engine is probably one of the Top 20 inventions of the last century since it has had such a huge impact on distance we can travel and how fast to get there 🙂
Personally I love the invention. It has taken me places and given me memories for life. If it wasn’t for a jet engine I wouldn’t be married to my wife and live here in Canada. We seem to forget how important they are and how they keep us safe by keeping the airplane up in the air 🙂
So why should we be grateful for the Jet engine?
- They keep us safe and alive.
- They help us receive goods, gifts and other things fast.
- They transport us.
- They take us to places we have never been before.
- They let us meet people on the travels in the air.
- They help connect loved ones.
- They have made the world a smaller place.
- They help us do business face to face.
- They help us explore the skies.
- They help doing scientific research by driving planes into storms.
- They can make humans go faster than the speed of sound.
- They help keeping husbands and wife’s safe in a war.
- They take you on a honeymoon with your new wife or husband.
- They take you hiking in the Andees.
- They help you travel over big seas comfortably.
- They have saved life’s.
- They named our local NHL Ice hockey Team Jets 🙂
There is so much more great things to be grateful for a jet engine for, but I only came up with a few.
How about you fill in the blanks?? Comment under with why we should be grateful for the Jet engine.
Here is a little background on what a jet engine is and a little history 🙂
A jet engine is a reaction engine that discharges a fast moving jetwhich generates thrust by jet propulsion in accordance withNewton’s laws of motion. This broad definition of jet engines includesturbojets, turbofans, rockets, ramjets, and pulse jets. In general, most jet engines are internal combustion engines but non-combusting forms also exist.
In common parlance, the term jet engine loosely refers to an internal combustion airbreathing jet engine (a duct engine). These typically consist of an engine with a rotary (rotating) air compressor powered by a turbine (“Brayton cycle“), with the leftover power providing thrust via a propelling nozzle. These types of jet engines are primarily used by jet aircraft for long distance travel. Early jet aircraft used turbojetengines which were relatively inefficient for subsonic flight. Modern subsonic jet aircraft usually use high-bypass turbofan engines which offer high speed with fuel efficiency comparable (over long distances) to piston and propeller aeroengines.
How about a little history?
Jet engines can be dated back to the invention of the aeolipile before the first century AD. This device used steam power directed through two nozzles to cause a sphere to spin rapidly on its axis. So far as is known, it was not used for supplying mechanical power, and the potential practical applications of this invention were not recognized. It was simply considered a curiosity.
Jet propulsion only took off, literally and figuratively, with the invention of the gunpowder-powered rocket by the Chinese in the 13th century as a type of fireworks, and gradually progressed to propel formidable weaponry. However, although very powerful, at reasonable flight speeds rockets are very inefficient and so jet propulsion technology stalled for hundreds of years.
The earliest attempts at airbreathing jet engines were hybrid designs in which an external power source first compressed air, which was then mixed with fuel and burned for jet thrust. In one such system, called a thermojetby Secondo Campini but more commonly, motorjet, the air was compressed by a fan driven by a conventional piston engine. Examples of this type of design were the Caproni Campini N.1, and the Japanese Tsu-11 engine intended to power Ohka kamikaze planes towards the end of World War II. None were entirely successful and the N.1 ended up being slower than the same design with a traditional engine and propeller combination.
Even before the start of World War II, engineers were beginning to realize that the piston engine was self-limiting in terms of the maximum performance which could be attained; the limit was due to issues related to propeller efficiency, which declined as blade tips approached the speed of sound. If engine, and thus aircraft, performance were ever to increase beyond such a barrier, a way would have to be found to radically improve the design of the piston engine, or a wholly new type of powerplant would have to be developed. This was the motivation behind the development of the gas turbine engine, commonly called a “jet” engine, which would become almost as revolutionary to aviation as the Wright brothers‘ first flight.
The key to a practical jet engine was the gas turbine, used to extract energy from the engine itself to drive thecompressor. The gas turbine was not an idea developed in the 1930s: the patent for a stationary turbine was granted to John Barber in England in 1791. The first gas turbine to successfully run self-sustaining was built in 1903 by Norwegian engineer Ægidius Elling. Limitations in design and practical engineering and metallurgy prevented such engines reaching manufacture. The main problems were safety, reliability, weight and, especially, sustained operation.
The first patent for using a gas turbine to power an aircraft was filed in 1921 by Frenchman Maxime Guillaume.His engine was an axial-flow turbojet. Alan Arnold Griffith published An Aerodynamic Theory of Turbine Design in 1926 leading to experimental work at the RAE.
In 1928, RAF College Cranwell cadet  Frank Whittle formally submitted his ideas for a turbo-jet to his superiors. In October 1929 he developed his ideas further. On 16 January 1930 in England, Whittle submitted his first patent (granted in 1932). The patent showed a two-stage axial compressor feeding a single-sided centrifugal compressor. Practical axial compressors were made possible by ideas from A.A.Griffith in a seminal paper in 1926 (“An Aerodynamic Theory of Turbine Design”). Whittle would later concentrate on the simpler centrifugal compressor only, for a variety of practical reasons. Whittle had his first engine running in April 1937. It was liquid-fuelled, and included a self-contained fuel pump. Whittle’s team experienced near-panic when the engine would not stop, accelerating even after the fuel was switched off. It turned out that fuel had leaked into the engine and accumulated in pools, so the engine would not stop until all the leaked fuel had burned off. Whittle was unable to interest the government in his invention, and development continued at a slow pace.
In 1935 Hans von Ohain started work on a similar design inGermany, apparently unaware of Whittle’s work. His first device was strictly experimental and could only run under external power, but he was able to demonstrate the basic concept. Ohain was then introduced to Ernst Heinkel, one of the larger aircraft industrialists of the day, who immediately saw the promise of the design. Heinkel had recently purchased the Hirth engine company, and Ohain and his master machinist Max Hahn were set up there as a new division of the Hirth company. They had their first HeS 1 centrifugal engine running by September 1937. Unlike Whittle’s design, Ohain used hydrogen as fuel, supplied under external pressure. Their subsequent designs culminated in the gasoline-fuelled HeS 3 of 1,100 lbf (5 kN), which was fitted to Heinkel’s simple and compact He 178 airframe and flown by Erich Warsitz in the early morning of August 27, 1939, from Rostock-Marienehe aerodrome, an impressively short time for development. The He 178 was the world’s first jet plane.
Austrian Anselm Franz of Junkers‘ engine division (Junkers Motorenor “Jumo”) introduced the axial-flow compressor in their jet engine. Jumo was assigned the next engine number in the RLM 109-0xx numbering sequence for gas turbine aircraft powerplants, “004”, and the result was the Jumo 004 engine. After many lesser technical difficulties were solved, mass production of this engine started in 1944 as a powerplant for the world’s first jet-fighter aircraft, theMesserschmitt Me 262 (and later the world’s first jet-bomber aircraft, the Arado Ar 234). A variety of reasons conspired to delay the engine’s availability, causing the fighter to arrive too late to improve Germany’s position in World War II. Nonetheless, it will be remembered as the first use of jet engines in service.
Following the end of the war the German jet aircraft and jet engines were extensively studied by the victorious allies and contributed to work on early Soviet and US jet fighters. The legacy of the axial-flow engine is seen in the fact that practically all jet engines on fixed wing aircraft have had some inspiration from this design.
By the 1950s the jet engine was almost universal in combat aircraft, with the exception of cargo, liaison and other specialty types. By this point some of the British designs were already cleared for civilian use, and had appeared on early models like the de Havilland Comet and Avro Canada Jetliner. By the 1960s all large civilian aircraft were also jet powered, leaving the piston engine in low-cost niche roles such as cargo flights.
The efficiency of turbojet engines was still rather worse than piston engines but by the 1970s, with the advent ofhigh bypass turbofan jet engines, an innovation not foreseen by the early commentators such as Edgar Buckingham, at high speeds and high altitudes that seemed absurd to them, fuel efficiency was about the same as the best piston and propeller engines.
|“The sound of a jet, an engine warming up, even the clopping of shod hooves on pavement brings on the ancient shudder, the dry mouth and vacant eye, the hot palms and the churn of stomach high up under the rib cage.”|
|John Steinbeck quotes|
John Thore Stub Sneisen(c)