POWER-TO-WEIGHT RATIO: Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Aircraft Engines In-line engine Early aircraft, including Wright Brothers’. Advantage: narrow frontal area for low drag 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

Types of Engines – Aircraft Engines Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Aircraft Engines Rotary engine i.c.e. Early WWI Cylinders around crankcase, crankshaft bolted to airframe Entire engine rotates with the propeller Advantages: Lightweight, powerful, cheap, easy to manufacture Disadvantage: Difficult to fly, spread oil over plane http://en.wikipedia.org/wiki/Aircraft_engine http://www.diracdelta.co.uk/science/source/r/o/rotary%20engine/9cyl-rotary-001.jpg

Types of Engines – Aircraft Engines Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Aircraft Engines Radial engine i.c.e. Post WWI Cylinders around crankcase, bolted to airframe Propeller rotates with crankshaft Advantages: Good P/W ratio, cools evenly, runs smoothly Disadvantage: blunt and aerodynamically inefficient profile http://en.wikipedia.org/wiki/Radial_engine http://en.wikipedia.org/wiki/Aircraft_engine

Types of Engines – Gas Turbine Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Gas Turbine Gas Turbine 1934: first “free-piston engine” http://www.its.uni-karlsruhe.de/english/ITS-Profil.php http://science.howstuffworks.com/ http://www.grc.nasa.gov/WWW/K-12/airplane/Animation/airpar/Images/aroll.gif

Types of Engines – Gas Turbine Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Gas Turbine Compressor Compresses incoming air to high pressure (up to 30 times) 2) Combustion Area Burns fuel and produces high pressure, high velocity gas 3) Turbine Extracts energy from combustion http://science.howstuffworks.com/

Types of Engines – Gas Turbine Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Gas Turbine Gas Turbine (cont.) Advantages: High power-to-weight ratio Smaller than reciprocating engines of same power Disadvantages: Expensive High speeds and temperatures – materials More fuel while “idling” http://science.howstuffworks.com/

Types of Engines – Gas Turbine Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Gas Turbine Gas Turbine (cont.) Uses: Jet Engines Electrical Generation Other Vehicles Tanks Naval Vessels Automobiles http://en.wikipedia.org/wiki/Gas_turbine#Types_of_gas_turbines

Types of Engines – Gas Turbine Power Plants – Engines Types of Engines – Gas Turbine Gas Turbine (cont.) Turbine Jet Engine THRUST http://en.wikipedia.org/wiki/Gas_turbine#Types_of_gas_turbines

Types of Engines – Gas Turbine Power Plants – Engines Types of Engines – Gas Turbine Gas Turbine (continued) Turbofan http://en.wikipedia.org/wiki/Gas_turbine#Types_of_gas_turbines THRUST

Types of Engines – Other Types Power Plants – Engines IOT POLY ENGINEERING 3-6 Types of Engines – Other Types Other types of engines Bourke Wankel Sterling Carnot Heat Engine Controlled Combustion IRIS Engine Five-stroke Six-stroke http://science.howstuffworks.com/

Non-Renewable Fuels – Petroleum IOT POLY ENGINEERING 3-2 Petroleum Distillation http://img.alibaba.com/photo/12033517/Crude_Oil_Refinery_Products_.jpg