An important issue for the aeronautical industry is the reduction of aircraft noise. The rotor–stator interaction is a predominant part of the noise emission. Presented are an introduction to these interaction theories, whose applications are numerous. For example, the conception of air-conditioning ventilators requires a full understanding of this interaction. An important issue for the aeronautical industry is the reduction of aircraft noise. The rotor–stator interaction is a predominant part of the noise emission. Presented are an introduction to these interaction theories, whose applications are numerous. For example, the conception of air-conditioning ventilators requires a full understanding of this interaction.