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POLY ENGINEERING3-6

Power Plants – EnginesTypes of Engines – Aircraft Engines

5. In-line engine a. Early aircraft, including Wright Brothers’.b. Advantage: narrow frontal area for low dragc. Disadvantage: Poor power-to-weight ratio (heavy

crankcase and crankshaft)In ALL engines, we want a high power-to-weight ratio.

POWER-TO-WEIGHT RATIO:amount of power you get out of the engine compared to the

weight of the engine itself

P Wt

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POLY ENGINEERING3-6

Power Plants – EnginesTypes of Engines – Aircraft Engines

6. Rotary engine i.c.e.a. Early WWI b. Cylinders around crankcase, crankshaft bolted to airframec. Entire engine rotates with the propellerd. Advantages: Lightweight, powerful, cheap, easy to

manufacturee. Disadvantage: Difficult to fly, spread oil over plane

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POLY ENGINEERING3-6

Power Plants – EnginesTypes of Engines – Aircraft Engines

7. Radial engine i.c.e.a. Post WWIb. Cylinders around crankcase, bolted to airframec. Propeller rotates with crankshaftd. Advantages: Good P/W ratio, cools evenly, runs smoothlye. Disadvantage: blunt and aerodynamically inefficient profile

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POLY ENGINEERING3-6

Power Plants – Engines

Types of Engines – Gas Turbine

8. Gas Turbine1934: first “free-piston engine”

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POLY ENGINEERING3-6

Power Plants – Engines

Types of Engines – Gas Turbine1) Compressor

Compresses incoming air to high pressure (up to 30 times)

2) Combustion AreaBurns fuel and produces high pressure, high velocity gas

3) TurbineExtracts energy from combustion

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POLY ENGINEERING3-6

Power Plants – EnginesTypes of Engines – Gas Turbine

8. Gas Turbine (cont.)a. Advantages:

1) High power-to-weight ratio2) Smaller than reciprocating engines of same power

b. Disadvantages:1) Expensive2) High speeds and temperatures – materials3) More fuel while “idling”

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POLY ENGINEERING3-6

Power Plants – EnginesTypes of Engines – Gas Turbine

8. Gas Turbine (cont.)c. Uses:

1) Jet Engines2) Electrical Generation3) Other Vehicles

1) Tanks2) Naval Vessels3) Automobiles

Power Plants – EnginesTypes of Engines – Gas Turbine

8. Gas Turbine (cont.)4) Turbine Jet Engine THRUST

Power Plants – EnginesTypes of Engines – Gas Turbine

8. Gas Turbine (continued)4) Turbofan

THRUST

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POLY ENGINEERING3-6

Power Plants – EnginesTypes of Engines – Other Types

8. Other types of engines1) Bourke2) Wankel3) Sterling4) Carnot Heat Engine5) Controlled Combustion6) IRIS Engine7) Five-stroke8) Six-stroke

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POLY ENGINEERING3-2

Non-Renewable Fuels – Petroleum

PetroleumDistillation