Aerodynamics in Aircraft Design

The force that propels an aircraft forward. It is generated by the engines.

The force that pulls an aircraft downwards due to gravity.

The combined force of lift and drag acting on an aircraft.

The upward force that opposes weight and allows aircraft to fly. It is generated by the wings.

The force that opposes motion through the air. It acts opposite to the direction of travel.

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

A measure of how efficiently an airfoil generates lift. It is a ratio of lift to dynamic pressure.

A measure of how much drag an airfoil produces. It is a ratio of drag to dynamic pressure.

The point on an airfoil's chord line where all aerodynamic forces are concentrated. Expressed as a percentage of the airfoil's chord.

For an asymmetric airfoil, when the angle of attack increases, the CP moves forward, often to about 1/4 of the chord length from the leading edge.

For an asymmetric airfoil, when the angle of attack decreases, the CP moves backward.

The lift produced by an airfoil depends on the shape and angle of attack, air density, air velocity, and the wing area. It's represented by the formula L = ½ρV²SCL

The coefficient of lift (CL) measures the efficiency of an airfoil's shape in producing lift.

The dynamic pressure (q) is a measure of the kinetic energy of the air. It is calculated as ½ρV². This value is used in many calculations, including those related to pitot-static instruments and drag calculations.

The difference in air pressure between the upper and lower surfaces of an airfoil, caused by the faster air flow over the curved upper surface and slower air flow under the flatter lower surface.

The downward deflection of air caused by the airfoil's shape, creating an equal and opposite upward force on the airfoil.

Newton's third law states that for every action, there is an equal and opposite reaction. In the case of an airfoil, pushing air downwards (downwash) results in an equal and opposite upward force.

The distribution of pressure forces across the airfoil surface, indicating the magnitudes and directions of force at different points.

The area where the airflow separates at the leading edge of the airfoil, splitting into upper and lower flows.

The faster airflow over the top surface of an airfoil creating a lower pressure zone which contributes to the lift force.

The slower airflow under the lower surface of an airfoil creating a higher pressure zone, which also contributes to the lift force.

For a non-viscous, incompressible fluid in steady flow, the sum of pressure, potential and kinetic energy per unit volume is constant at any point.

In a streamline flow of an ideal fluid, the sum of potential, kinetic, and pressure energy is constant.

According to Bernoulli's Principle, air traveling over the top of an airfoil or wing must travel further and hence faster than air traveling the shorter distance under the wing in the same period. This produces a pressure difference, creating lift.

A short circular tube with large openings at both the front and rear ends, with a restrictor between the openings.

The Venturi effect is the reduction in static pressure of a fluid resulting from an increase in speed as the fluid passes through a constricted section of a duct (Venturi tube).

When a fluid flows through a Venturi tube, the streamlines gather where the speed is greater and the pressure is lowest.

Air velocity increases when the pressure decreases, and vice versa.

A numerical model used to simulate the flow of fluids. For a fluid, this could include the velocity, density, and pressure.

The coefficient of lift (Cl) is a dimensionless constant that reflects how efficiently a wing generates lift relative to its size, shape, and speed. It is typically determined through wind tunnel testing.

The lift force generated by an object is directly proportional to the density of the air it's moving through. Denser air provides more lift, while less dense air results in less lift.

Lift is directly proportional to the square of the speed at which an object moves through the air. Faster speeds lead to significantly increased lift.

The amount of lift generated by an object depends on its size. A larger wing area results in more lift. Doubling the area doubles the lift.

The curvature or shape of an airfoil, referred to as camber, influences the flow of air around it and the amount of lift generated. More camber typically generates more lift.

The angle of attack (AoA) is the angle between the wing's chord line and the direction of airflow. For small angles, lift is directly proportional to AoA. At higher angles, the relationship becomes more complex.

The lift generated by an airfoil at very low angles of attack may be significantly less than the lift generated by a symmetric airfoil. The curve in the airfoil itself helps generate lift even at zero angle of attack.

Factors like slats, flaps, and spoilers, which are movable control surfaces on aircraft wings, can significantly affect lift and drag. They allow for greater lift during takeoff and landing.

The point at which an airfoil's angle of attack is so high that airflow becomes turbulent, causing a sharp decrease in lift and a significant increase in drag.

When the airflow over an airfoil becomes chaotic and disorganized, reducing lift and increasing drag. This happens when the angle of attack surpasses the stalling angle.

Methods used to increase lift, especially during takeoff and landing. Includes leading-edge slats and trailing-edge flaps.

Flaps and slats are among the leading and trailing edge devices used for lift augmentation.

A wing without any lift-enhancing devices deployed.

The curved shape of an airfoil, determining the amount of lift produced. It can be adjusted by using flaps and slats.

Lowering flaps increases the camber of the wing, resulting in a significant lift increase – around 60%.