Aerodynamics and Atmospheric Pressure Quiz

The amount of mass contained in a given volume of air.

Density decreases with altitude. It is also affected by temperature and humidity.

Air density increases as temperature drops.

Increased humidity makes air less dense because water molecules are lighter than air molecules.

Starts at 15°C at sea level and decreases by about 2°C per 1000 feet of altitude.

The amount of moisture in the air compared to the maximum amount it can hold at that temperature.

Relative humidity decreases with altitude.

The speed of an aircraft relative to the surrounding air.

The study of how air moves around objects, especially aircraft. This helps us understand how airplanes fly.

A shape designed to reduce air resistance. It allows air to flow smoothly around it with minimal disturbance.

A line that shows the direction of air flow around an object. Helps visualize how air moves.

The layer of air closest to the surface of an aircraft. The air particles here are slowed down by friction with the surface.

The boundary layer is divided into two regions: a smooth laminar flow, where the air moves in a smooth, straight line, and a turbulent flow, where the air moves in a chaotic, swirling fashion.

A key factor in aircraft performance. A smooth boundary layer allows for less drag, enabling the aircraft to fly more efficiently and smoothly.

The effect of the shape of an object on airflow and resistance. A streamlined shape creates less resistance, allowing for more efficient movement.

Streamlined shape creates the least resistance, while a flat plate encounters the most. Different shapes result in different levels of resistance.

The thin layer of air that clings to the surface of an object and where airflow speed changes.

A type of airflow where air particles move smoothly in parallel lines, following the shape of the object.

A type of airflow where air particles move chaotically and don't follow the shape of the object.

The point where laminar flow transitions into turbulent flow.

A reduction in drag and increased efficiency.

Increased drag and decreased efficiency.

The friction between air and a surface that causes the air to slow down.

The air closest to the surface comes to a complete stop, while layers further away slow down gradually.

The shape of a wing, blade, propeller, rotor, turbine, or sail as seen in cross-section.

An airfoil provides lift while minimizing resistance (drag) as it moves through the air.

No lift is generated at zero angle of attack.

Lift is generated even at small angles of attack.

The curvature of an airfoil (wing) above and below the chord line.

An imaginary line drawn from the center of curvature of the leading edge to the trailing edge, equidistant from the top and bottom surfaces of an airfoil.

An imaginary line connecting the leading edge to the trailing edge of the airfoil.

The curve surfaces, that gives the airfoil its shape.

The point on an airfoil where airflow comes to a complete stop, resulting in zero velocity relative to the airfoil.

The pressure at the stagnation point is equal to the total pressure, which is the sum of static pressure and dynamic pressure.

A rotating flow of air created when high-pressure air on the bottom of an airfoil pushes around to the low-pressure area on the top.

The angle between the chord line of an airfoil and the direction of the oncoming airflow.

The movement of air from high pressure to low pressure, creating a force that lifts the aircraft.

The movement of air from the tip of a wing towards the root, creating a low-pressure area above the wing.

The movement of air from the root of the wing towards the tip, creating a high-pressure area under the wing.

The area behind a large aircraft where turbulent air produced by the wings can pose a hazard to smaller aircraft.

The point on an airfoil where the average aerodynamic force acts. It's the point where the upward force (lift) and downward force (weight) balance.

The angle between the wing's chord line and the direction of the oncoming airflow.

As the angle of attack increases, the center of pressure moves forward on the airfoil, usually reaching a point about ¼ chord length from the leading edge.

The shape of an airplane's wing when viewed from above, which influences its aerodynamic characteristics.

A wing shape that is simple to build and common in older aircraft. It's known for good slow-flight characteristics and stalls beginning at the root.

The most aerodynamically efficient wing shape, but it's difficult to manufacture. It's famously used on the Supermarine Spitfire.

A wing shape that's structurally and aerodynamically efficient, easier to build than elliptical wings, and the most common type used.

Used on high-speed aircraft, allowing sleek designs. It's the most popular design for transport aircraft.