21.2 Internal Combustion Engines

fuel cell

A device that converts the chemical energy of a fuel, such as hydrogen, into electrical energy

ethanol

A liquid fuel made from corn

piston

A plug that slides inside a cylinder of an engine

jet engine

A type of gas turbine engine that pushes a vehicle forward as hot air and exhaust are shot out the back of the engine

external combustion engine

An engine that burns fuel to create energy; its power source is outside the engine

rotary motion

Circular motion

emissions

Gases released into the air as a result of combustion

turbine

(TUR-bin) A disk or wheel that changes the energy of moving gases or liquids into rotary motion

reciprocating motion

(ree-SIP-roh-kay-ting) In an engine, up-and-down or back-and forth motion that occurs in a straight line

propellant

In transportation, a fuel mixture that causes an explosive thrust

internal combustion engine

In transportation, an engine in which the fuel is burned inside

ignition system

In transportation, an engine system that starts the fuel burning

thrust

The high pressure that pushes a jet engine forward

crankshaft

The part of an engine that changes the reciprocating motion of the pistons to the rotary motion that turns the wheels

maintenance

The process of inspecting and servicing a system on a regular basis to enable it to continue functioning properly, to extend its life, or to upgrade its capability