Download
slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
JET PROPULSION PowerPoint Presentation
Download Presentation
JET PROPULSION

JET PROPULSION

1457 Views Download Presentation
Download Presentation

JET PROPULSION

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. JET PROPULSION Part 3 Types of Jet Engines

  2. Engine Types Turbo Jet Avon, Viper, Olympus 593 Turbo Fan - Bypass Engines LOW BYPASS Spey, BR700 MEDIUM BYPASS Pegasus, BR715, V2500 LARGE BYPASS RB211, Trent Series Turbo Prop PROPELLER Dart, Tyne, BR715TP Turbo Shaft HELICOPTER Lycoming T55, Gem RN SHIPS Marine Spey POWER GENERATION Industrial Spey & Trent There are FOUR basic types of Jet Engines

  3. Engine Types In this lesson we shall examine Turbo Jets and Turbo Fans

  4. Questions ?

  5. Turbo Jet The turbojet is the simplest and earliest form of gas turbine. Used principally in high speed aircraft where its relatively low frontal area and high jet velocity are advantages. Examples are the Concord supersonic transport and a variety of military aircraft including the Dominie/HS125.

  6. Turbo Jet Compressor Turbine Rolls Royce Avon Single Shaft Turbo Jet In a Single Shaft layout the ratio of the turbine speed to the compressor speed is 1:1

  7. Turbo Jet Rolls Royce Avon At low rpm the rear of the compressor cannot get rid of all the air from the front of the compressor This can result in the rear end of compressor ‘choking’ So air blasts forwards Flame almost goes out - no power – no thrust. This is called: - COMPRESSOR SURGE So the surplus air needs to be ‘dumped’ overboard

  8. Turbo Jet Rolls Royce Avon Rear end of compressor ‘unchoked’ Movement of air restored Air dumped overboard Power restored BUT air dumped sideways out of the engine produces no thrust. So a more efficient system was required

  9. Turbo Jet The Olympus 593 The Two Shaft Layout Allows front end of compressor to slow down – move less air and Allows rear end of compressor to speed up – move more air High Pressure Compressor driven by High Pressure Turbine driven by Low Pressure Compressor Low Pressure Turbine Compressor surges lessened No wasted energy/thrust

  10. Questions ?

  11. Turbo Fan The main advantage of a turbofan (by-pass) engine are it reduces overall jet velocity giving, Improved Low Speed Efficiency, Lower Noise Levels and Improved Specific Fuel Consumption, features which make the turbofan ideal for both civil and military aircraft. There are three types of by-pass engines, Low, Medium and High.

  12. Turbo Fan Turbofan engines are loosely categorised by the size of the bypass compared to the core flow. By dividing the bypass mass air flow by the core engine mass airflow, the Bypass Ratio can be determined The low bypass ratio is approximately 1:1. Half the air goes through the core or hot section, the other half goes through the bypass. Medium bypass engines have a 5:1 ratio, while High bypass have a ratio of 10:1 or more.

  13. Questions ?

  14. Turbo Fan Low Bypass Engine Rolls Royce Spey Adour BR710 Series This improves propulsive efficiency at lower aircraft speeds Part of the air is compressed fully and passes into the combustion chamber, while the remainder is compressed to a lesser extent and ducted around the hot section.

  15. Turbo Fan Low Bypass Engine Rolls Royce Spey Adour BR710 Series Schematic diagram of a simplified Low Bypass Engine

  16. Turbo Fan Medium Bypass Engine Pegasus The Pegasus medium bypass engine is unique in that it can provide Vertical Thrust for VSTOL operation and forward thrust for normal flight. Vectored Thrust manipulates the direction of thrust from the engine, as used in the most successful BAe Harrier.

  17. Turbo Fan Medium Bypass Engine Pegasus Schematic diagram of a simplified Medium Bypass Engine Fan Exhaust

  18. Turbo Fan High Bypass Engine RB211 Series (Trent) In service with RAF – Wide-body Tristar Tanker/Transport Boeing 747 and later series, Airbus A330 and larger a/c

  19. Turbo Fan High Bypass Engine RB211 Series (Trent) Three shaft layout Schematic diagram of a simplified High Bypass Engine

  20. Questions ?

  21. Engine Types Avon, Viper, Olympus 593 Turbo Jet Turbo Fan LOW BYPASS MEDIUM BYPASS HIGH BYPASS Spey, BR700 Pegasus, BR715, V2500 RB211, Trent Series

  22. Questions ?

  23. Check of Understanding Which of these is a turbojet engine? The Tyne The Olympus The Spey The Pegasus

  24. Check of Understanding How is the bypass ratio of a bypass type jet engine determined? By the diameter of the fan and the length of the compressors By the difference between atmospheric pressure and bypass pressure By the diameter of the fan By dividing the bypass mass air flow by the core engine mass airflow

  25. Check of Understanding The illustration shows a layout of one type of engine.  What is this layout called? Turbojet Turbofan Turboprop Turboshaft

  26. Check of Understanding Which application or type of operation best suits the turbojet engine? In low speed aircraft operating at high altitudes In high speed aircraft where low frontal area is an advantage • In low speed aircraft • operating at low altitudes • In helicopters

  27. Check of Understanding In a single shaft jet engine, what is the ratio of the turbine speed to the compressor speed? 10:1 5:1 2:1 1:1

  28. Check of Understanding The illustration shows a layout of one type of engine.  What is this layout called? Turbojet Low By-Pass Medium By-Pass High By-Pass

  29. Check of Understanding Which of these is a turbojet engine? The Pegasus The Avon • The Spey • The Adour

  30. Check of Understanding In a bypass engine, part of the air is fully compressed and is passed into the combustion chamber, whilst the remainder is compressed to a lesser extent and is ducted around the hot section. Which type of engine normally employs this system? Tupboprop Turbofan Turbojet Turboshaft

  31. Check of Understanding The illustration shows a layout of one type of engine.  What is this layout called? Turbojet Turbofan Turboprop Turboshaft

  32. Check of Understanding What does VSTOL stand for? Very Short Take-Off and Landing Vertical Stable Take-Off and Landing Very Stable Take-Off and Landing Vertical Short Take-Off and Landing

  33. Check of Understanding In the turbofan engine, some air is not fully compressed and is made to bypass the combustion chamber thereby reducing the overall jet velocity. An important consequence is that : All the residual thrust is removed The propulsive efficiency at higher aircraft speed is improved The residual thrust is higher The propulsive efficiency at lower aircraft speeds is improved

  34. Check of Understanding The illustration shows a layout of one type of engine.  What is this layout called? Turbojet Low By-Pass Medium By-Pass High By-Pass

  35. Check of Understanding Complete the sentence: Vectored thrust (or thrust Vectoring) …? Manipulates the direction of thrust from the engine Does not control the angular velocity of the aircraft Is a method of extracting more power from the internal combustion engine Is a means of jet engine afterburner

  36. Check of Understanding A main advantage of a turbofan engine is: It can be used in helicopters It is mainly used on small light aircraft It is faster than a turbojet It has low speed efficiency

  37. Check of Understanding The illustration shows a layout of one type of engine.  What is this layout called? Turbojet Low By-Pass Medium By-Pass High By-Pass

  38. Check of Understanding Which of these is a turbojet engine? The Pegasus The Viper • The Spey • The Adour

  39. Questions ?

  40. JET PROPULSION End of Presentation