Читать книгу Flight Theory and Aerodynamics - Joseph R. Badick - Страница 95

If an airfoil is subjected to a moving airflow, velocity and pressure changes take place that create pressure disturbances in the airflow surrounding it. These disturbances originate at the airfoil surface and propagate in all directions at the speed of sound. If the flight path velocity is subsonic, the pressure disturbances that are moving ahead of the airfoil affect the airflow approaching the airfoil (Figure 3.18). As the arrow indicates there are slight changes with the streamlines ahead of the leading edge of the airfoil.