Air and Aerodynamics/Flight

propeller

A mechanical device that rotates to push against air or water. It forces an aircraft or ship forward - a propeller is a twisted airfoil.

airfoil

A shape designed to provide lift when air flows around it

yaw

A side-to-side motion of the nose of the aircraft. It is when the aircraft is turning right or left.

wings (airplane)

Rigid horizontal structures that project from both sides of an aircraft and supports it in the air.

roll

Rotation of the fuselage. One wing will tilt up and the other will tilt down.

aileron

Sections of the wing, which can move up or down and control roll.

control surfaces (on a plane)

Small surfaces that can be moved to alter airflow and change an airplane's altitude.

mass

The amount of matter (atoms and/or molecules) in an object.

glider

An aircraft that flies without an engine - its pilot tries to find updrafts of air to gain height and extend the flight.

Jet engine

An engine that generates a powerful thrust in a chamber where the explosion of the burning fuel pushes on the airplane in a forward direction but escapes out the back.

four forces of flights

Lift, thrust, drag and weight.

air

Mixture of gases that makes up the Earth's atmosphere. It is mostly nitrogen (78 percent), oxygen (21 percent), water vapor (variable), argon (0.9 percent), and carbon dioxide (0.04 percent). Pure air has no scent or color. On another planet (e.g., Mars), the "air" would have a different composition. There is no air in space.

air pressure

The force exerted on the surface of objects by the weight of air particles - it acts from all directions and increases with increased concentration of air molecules.

friction

The force that resists motion of one body over or through another. Air particles create friction and cause drag on objects moving through it.

Weight

The heaviness of an object. This measure comes from gravity pulling down on objects. Objects with more mass (matter) have more weight. To fly, an aircraft needs something to push it in the opposite direction from gravity. This is one of the forces of flight.

rudder

The hinged section of the tail of the airplane, which helps the plane move right or left; that is yaw.

elevators

The horizontal part of a plane's stabilizer used to control pitch.

fuselage

The main body of the plane.

lift

The push that lets something move up. It is the force that is the opposite of weight. For an aircraft to move upward, it must have more of this force than weight. Airplane - wing design causes this. Helicopter - rotor blades create this. Hot air balloon -hot air in the balloon being less dense than the air around it causes this.

streamlining

The shaping of an object so that a gas or liquid will move easily around it.

aerodynamics

The way air moves around things. Anything that moves through air pushes air molecules out of the way. A rocket blasting off the launch pad, a kite, planes and cars are just some examples.

drag

This is a force that tries to slow something down. It makes it hard for an object to move. It is harder to walk or run through water than through air. That is because water is more dense than air. The more air that hits a surface, the stronger this force. The shape of an object also changes the amount of this force on an object. Round surfaces - most have less of this force than flat ones. Narrow surfaces - usually have less of this force than wide ones.

thrust

This is the force that is the opposite of drag. This force is a push that moves something forward. For an aircraft to keep moving forward, it must have more of this than drag. Small airplane - might get this from a propeller. Larger airplane - might get this from jet engines. Gliders - do not have this force. They can only fly until the drag causes then to slow down and land.

pitch

Up or down attitude of the nose of the plane. If the nose is pointed up, the airplane will climb into the sky. If the nose is pointed down, the airplane is moving toward the ground.

Bernoulli's principle

When the speed of a fluid is low/slower (water or air), the pressure is high. When the speed of a fluid is high/faster the pressure is low. The faster that air moves across a surface, the lower the air pressure.