The study of airflow over open cavities is fundamental to the design of modern aircraft, both in civil and military aviation. Such flow is inherently unstable and leads to pressure oscillations, including broadband components and periodic tonal components, which can interfere with the aerodynamics of the aircraft. Therefore, such cavities have been investigated since the 1950s. Rossiter was the first to describe the phenomenon, identifying the cause of the tonal pressure oscillations (which will later be called Rossiter modes) and deriving an empirical formula for their frequency, which will later be refined by Heller. Subsequent studies have discovered the existence of cavities in which the periodic pressure components are reduced, if not completely absent, and identified other parameters that influence the flow behavior, such as the cavity length-to-depth, length-to-width and width-to-depth ratios, and the Reynolds and Mach numbers.