Käyntikulma

Käyntikulma is a Finnish term that translates to "angle of attack" in English. It refers to the angle between the chord line of an airfoil (such as a wing or propeller blade) and the direction of the oncoming relative wind. This angle is crucial in determining the amount of lift and drag generated by the airfoil.

When the angle of attack is increased, the lift produced by an airfoil generally increases, up to a certain point. However, beyond a critical angle, the airflow over the upper surface of the airfoil separates, leading to a dramatic loss of lift and a significant increase in drag. This phenomenon is known as a stall.

The käyntikulma is a fundamental concept in aerodynamics and is vital for the design and operation of aircraft, wind turbines, and other systems that rely on the interaction of air with surfaces. Pilots actively manage the angle of attack to control their aircraft's altitude and airspeed, especially during takeoff, landing, and maneuvering. Propeller blades also have an angle of attack that is adjusted by the propeller governor to optimize engine performance under varying conditions. Understanding and controlling the käyntikulma is essential for efficient and safe operation in many engineering applications.