CHORD LINE OF AN AIRFOIL HOW TO

The term is also applied to compressor and turbine aerofoils in gas turbine engines such as turbojet, turboprop, or turbofan engines for aircraft propulsion. (If a wing has a rectangular planform, rather than tapered or swept, then the chord is simply the width of the wing measured in the direction of airflow.) The term chord is also applied to the width of wing flaps, ailerons and rudder on an aircraft. The chord of a wing, stabilizer and propeller is determined by measuring the distance between leading and trailing edges in the direction of the airflow. The wing, horizontal stabilizer, vertical stabilizer and propeller/rotor blades of an aircraft are all based on aerofoil sections, and the term chord or chord length is also used to describe their width. For a turbine aerofoil the chord may be defined by the line between points where the front and rear of a 2-dimensional blade section would touch a flat surface when laid convex-side up. The point on the leading edge used to define the chord may be the surface point of minimum radius. The chord length is the distance between the trailing edge and the point where the chord intersects the leading edge. The air on the upper surface has a tendency to flow in toward, and the air on the underside tends to flow towards the tip of the wing.In aeronautics, the chord is an imaginary straight line joining the leading edge and trailing edge of an aerofoil. When an airfoil is flown at a positive AOA, a pressure differential exists between the upper and lower surfaces of the airfoil. The total drag of an aircraft is composed of many drag forces, but only three will be studied: parasitic drag, profile drag and induced drag. Examine the figure opposite, noting how the LC increases until the critical angle of attack is reached, then decreases rapidly with any further increase in the angle of attack. This is the critical angle of attack at stall, called the CL-MAX critical angle of attack. When the aircraft reaches the maximum angle of attack, the lift begins to decrease rapidly. The greater the angle of attack, the greater the lift (all other factors being equal). Each time the handle or handle is moved forward or backward, the angle of attack is changed.

When lift is greater than weight, the aircraft gains altitude.

If lift becomes less than weight, the aircraft loses altitude. In stabilized level flight, when the lift force is equal to the weight force, the aircraft is in a state of equilibrium and neither gains nor loses altitude. Lift is required to counteract the aircraft’s weight (which is caused by the force of gravity acting on the mass of the aircraft). Lift is the upward force on the wing acting perpendicular to the relative wind. This relationship is simple, but important in understanding the aerodynamics of flying. Weight has a definite relationship to lift. It will be noted that CG is of major importance in an aircraft, for its position has a great bearing upon stabilite. If the aircraft were supported at its exact CG, it would balance in any attitude. The CG may be considered as a point at which all the weight of the aircraft is concentrated. Weight - Gravity is the pulling force that tends to draw all bodies to the center of the earth. In level flight, lift opposes the downward force of weight Lift - is a force that is produced by the dynamic effect of the air acting on the airfoil, and acts perpendicular to the flight path through the center of lift (CL) and perpendicular to the lateral axis. As a general rule, drag opposes thrust and acts rearward parallel to the relative wind. Drag - a rearward, retarding force caused by disruption of airflow by the wing, rotor, fuselage, and other protruding objects. As a general rule, it acts parallel to the longitudinal axis. It opposes or overcomes the force of drag. Thrust - the forward force produced by the powerplant/ propeller or rotor. The four forces acting on an aircraft in straight-and-level, unaccelerated flight are thrust, drag, lift, and weight.

CHORD LINE OF AN AIRFOIL HOW TO

Understanding how these forces work and knowing how to control them with the use of power and flight controls are essential to flight. Thrust, drag, lift, and weight are forces that act upon all aircraft in flight.

Chord line of an airfoil