Hyökäyskulma

Hyökäyskulma, also known as angle of attack, is a fundamental concept in aerodynamics. It refers to the angle between the chord line of an airfoil and the direction of the oncoming relative wind. The chord line is an imaginary straight line connecting the leading edge and the trailing edge of the airfoil. The relative wind is the direction of the airflow as experienced by the airfoil.

The hyökäyskulma is a critical factor in determining the lift and drag forces generated by an airfoil. As the hyökäyskulma increases, the lift force generally increases, up to a certain point. However, beyond a specific angle, known as the critical angle of attack, the airflow over the upper surface of the airfoil separates, causing a dramatic loss of lift and a significant increase in drag. This phenomenon is called a stall.

For most airfoils, a small positive hyökäyskulma is necessary to generate lift. Even airfoils designed to produce zero lift at zero angle of attack will generate some lift at a slight positive angle. Conversely, a negative hyökäyskulma can result in a downward force, or negative lift. Pilots use changes in hyökäyskulma to control altitude and speed. Aircraft designers carefully select airfoil shapes and operating ranges to manage hyökäyskulma for optimal performance and safety. Understanding and controlling the hyökäyskulma is essential for the safe and efficient operation of any aircraft.