Presentation on theme: "Www.flyhigher.eu The Fly Higher Tutorial II Aircraft in the air: What Jet Engines Do Image Source: Rolls Royce Plc. 2013."— Presentation transcript:
www.flyhigher.eu The Fly Higher Tutorial II Aircraft in the air: What Jet Engines Do Image Source: Rolls Royce Plc. 2013
www.flyhigher.eu Birds are able to fly because of a variety of specialised adaptations. They need extreme level of energy to fly in the air which comes from their high metabolisms. Because of their very light bodies, birds are able to produce both the required lift and propulsion using their ‘flight feathers’. Introduction: How can birds fly in the air? Image source http://gimnasio- altair.com/webquest/flight/
www.flyhigher.eu A short video to demonstrate how birds can fly in the air : Introduction: How can birds fly in the air? Video source – Youtube Acknowledgement: www.pendulumswingmedia.com Please watch video 1 How do birds fly? Source Youtube Acknowledgement : www.pendulumswingmedia.com Edition Fly Higher
www.flyhigher.eu Like birds, for aircraft to stay in the air we need thrust and lift. Where do these come from? Why can we not just copy the birds? And what is Thrust ? Let us look at the basic concept. Introduction: Thrust Image source http://www.kids.ct.gov/kids/cwp/view.asp?q=330926
www.flyhigher.eu Based on Newton’s Third Law: Every action has an equal and opposite reaction Demo: Fill the balloon with air and let it go in free space - What happens ? So what happens to an aircraft fitted with a jet engine? Introduction: The physics behind thrust Source http://www.bloodhoundssc.com/shop/balloon-car-kit
www.flyhigher.eu Hot exhaust gases from the aircraft’s jet engines push on the air which in return produces opposite reaction on the engines. As the engines are securely fitted to the aircraft body, the aircraft moves in the forward direction. Who came up with this brilliant idea? Introduction: Aircraft in forward motion
www.flyhigher.eu In the 18 th Century – Sir Isaac Newton, an English physicist and mathematician proposed a theory of ‘rearward-channelled explosion’ which could propel a machine forward at a great speed. He foresaw a use of his third law of motion which we now take for granted. History How did it begin? Newton’s Steam Wagon Source http://www.globalsecurity.org/military/libr ary/policy/army/fm/1-506/Ch2.htm
www.flyhigher.eu In 1903, the year of the Wright Brothers’ first flight, their wooden and canvas bi-plane was fitted with a 12 horse power petrol engine. Their engine was a basic mechanical design, remarkably similar to a modern, four-cylinder car engine. Image courtesy: http://wright.nasa.gov/airplane/Images/eng2.gif History How did it begin?
www.flyhigher.eu Their aeroplane, Kitty Hawk, depended upon the propeller to give her thrust; the engine simply turned the propeller. Most modern, small light aircraft still use propellers… Can you suggest why? History How did it begin? In the next 30 or 40 years, aircraft became single- winged, metallic tubes; their engines were more powerful and fuel- efficient…but this principle did not change.
www.flyhigher.eu In 1930 Sir Frank Whittle from England patented the Turbo jet engine. By April 1941 (early in World War II), the new engine was ready for flight testing. The first flight of a Turbojet, the Gloster E28/39, was made on 15 th May 1941 at Cranwell in Lincolnshire, England. The engine’s exhaust would propel the aircraft NO PROPELLER!! History How did it begin? Source: www.frankwhittle.co.uk/content.php?act=vie wDoc&docId=15&level=top
www.flyhigher.eu In the basic “internal combustion engine” the “combustion” is, in truth, an explosion. This explosive energy is used to drive a set of pistons, and the exhaust is regarded as waste. The pistons can then turn the wheels of a car, the blades of a pump…. or the propeller of an aircraft. Fundamentals Engine function
www.flyhigher.eu In the Jet Engine, the exhaust is not simply waste, but the source of the thrust that moves the aeroplane forward. Fundamentals Engine function Please watch video 2 Inside a Jet Engine Source Youtube Acknowledgement : www.wydea.com Edition Fly Higher
www.flyhigher.eu There are even different kinds of jet engines. The Airbus A380 – with 525 Passenger the largest long range civil aircraft in the world – uses turbofan engines, refined versions of Whittle’s original that include a massive fan to accelerate the air entering the jet engine as well as contribute to the thrust exactly as a propeller does. Turbofan Types of Engine Why are different engines used?
www.flyhigher.eu Different aircraft need different types of engine… Can you guess what these are and why they are used? Ramjet Turbojet Rocket Types of Engine Turbofans are not the only choice h ttps://encrypted- tbn2.gstatic.com/images?q=tbn:ANd9GcQ1V5eCFRb PSkLKrz68Ab_AGlud0UDUDQ0vR7dmp_OhHr1Xqu8 NDg http://img.bhs4.com/64/e/64e5d996fcdce9 5195acd4621cb79fb4f8ec776a_large.jpg https://upload.wikimedia.org/wikipedia/co mmons/d/d3/Atlantis_taking_off_on_STS- 27.jpg
www.flyhigher.eu Different aircraft need different types of engine… Can you guess what these are and why they are used? Turbo-prop Piston-prop Types of Engine Turbofans are not the only choice http://www.instablogs.com/wp- content/uploads/2012/07/hb350i_vM1uz_25013.jpg http://air-and-space.com/20050812%20Hawthorne/DSC_3008%20An- 2%20N2AN%20cn43798%20left%20front%20landing%20l.jpg
www.flyhigher.eu The choice of engine is based on : Thrust Required Performance Efficiency Cost Maintenance Civil aircraft require fuel efficient engines. Military Aircraft require high performance engines. Types of Engine Engyne section
www.flyhigher.eu Engine Components (Turbojet) Whittle’s original was a Turbojet engine like this Types of Engine Turbojet source: http://commons.wikimedia.org/wiki/File:Turbojet_operation-axial_flow-en.svg
www.flyhigher.eu The airlines’ choice. Turbofans are like Turbojets but also have a large fan accelerating the air’s entry into the engine and adding to the thrust as an internal propeller. Types of Engine Turbofan source : http://upload.wikimedia.org/wikipedia/commons/c/c0/Turbofan_operation.png
www.flyhigher.eu Turbo-Props have external propellers but use the jet engine idea to drive them Unlike Piston-Prop engines, Turbo-Props do not have pistons Types of Engine Turbo-prop Source http://upload.wikimedia.org/wikipedia/commons/4/4e/Turboprop_operation.png
www.flyhigher.eu Ramjet do not have compressors, fans and turbines like other jet engines. Technically, ramjets are the simplest form of jet engine. But they cannot produce thrust at zero speed, so Ramjet aircraft need other mechanisms to start their flight. Types of Engine Ramjet source - http://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Ramjet_operation.svg/300px-Ramjet_operation.svg.png
www.flyhigher.eu Unlike an aircraft engine, rocket engines carry both fuel and oxygen to energise the gas in the combustion chamber, before it exits through nozzle. Why do you think this is? Types of Engine Rocket engine source: http://www.grc.nasa.gov/WWW/k-12/VirtualAero/BottleRocket/airplane/Images/rockth.gif