Glossary of Terms

Airfoil
(also Aerofoil); A body (such as an airplane wing or propeller blade) designed to provide a desired reaction force when moving relative to the surrounding air
Angle of Attack
The angle between the nose of the aircraft and its velocity vector
Camber
The convex, curved shape of an airfoil from leading edge to trailing edge
Circulation

Combustion
The processes of burning fuel in an engine
Compression
A reduction in size or volume, as if by squeezing
Compressor
Part of an aircraft engine which compresses the gas prior to burn
Drag
The aerodynamic force, which opposes thrust, that tends to slow the forward motion of an aircraft
Escape velocity
The velocity required for a spacecraft to escape the earth's gravitational pull and travel in outer space
Free-body Diagram
A schematic of an object, which identifies all forces acting on the body
Fuselage
The central or body portion of an aircraft which accommodates the passengers and crew, or cargo
Harrier Jet
A single-engine fighter-bomber, first flown on Aug. 31, 1966, designed to fly from combat areas and aircraft carriers and to support ground forces
Hybrid Aircraft
An aircraft with moveable jet nozzles, which point downward to produce vertical thrust and backward for forward thrust
Hybrid Rocket
A rocket which uses a combination of liquid and solid propellants. In general the oxidizer, in a gaseous or liquid state, is combined with a solid fuel
Hypercapnia
The presence of excessive amounts of carbon dioxide in the blood
Hypoxia
A deficiency of oxygen reaching the tissues of the body
Intake
The opening through which air enters the aircraft engine
Lift
The component of the aerodynamic force acting on an aircraft, perpendicular to the relative wind, which causes an aircraft to rise in altitude
Light-piston
An engine which uses a light-weight piston to produce thrust
Nozzle
The rear opening of an aircraft engine through which the gas is discharged in order to produce thrust
Payload
The cargo being transported by the aircraft or spacecraft
Pitch
Rotation about a lateral axis such that the forward end rises or falls relative to the aft end
Propellant
The combination of both fuel and oxidizers, in liquid or solid form,which are burned by a rocket to produce thrust
Prebreath

Propellers
Devices that consists of a central hub with radiating blades which spin to propel the aircraft
Single-spool
Engine, such as a jet engine, in which a single compressor is connected by a shaft to a sinlge turbine
Thrust
The forward-directed force developed in a jet or rocket engine as a reaction to the rearward ejection of fuel gases
Three-spool
Engine, such as a turbofan, in which multiple turbines are connected by shafts to various compressors and fans
Turbine
Part of an aircraft engine which converts the kinetic energy of moving air into rotational power
Two-spool
Engine, such as a turbofan, in which two turbines are connected by multiple shafts to a compressor and fan
Weight
The downward force on an aircraft, which opposes lift, equal to the product of the mass of the aircraft and the local gravitational acceleration


Man-Vehicle Laboratory
MIT Department of Aeronautics and Astronautics
sablan@mit.edu
17 March 1997