Cavity acoustic tones suppression

A cavity system, comprising:

• a cavity and a spoiler;
• the spoiler comprising at least one plate having a front surface and a rear surface, an undulating edge in longitudinal cross-section, and a connecting structure for coupling the undulating edge the at least one plate,
• wherein the spoiler is positioned in proximity to a leading edge of the cavity, the leading edge being relative to an actual or intended flow direction of a fluid over the cavity, and
• wherein the spoiler is arranged with its longitudinal axis perpendicular or at an oblique angle to the actual or intended flow direction such that the front surface faces towards the flow direction;
• wherein the at least one plate has a height in a direction extending from the cavity (H) and a depth between the front surface and the rear surface (D), where H is larger than D;
• wherein the connecting structure has a first end attached to the front surface of the at least one plate or the rear surface of the at least one plate and a second end comprising the undulating edge;
• and
• wherein the undulating edge is either:
• offset from the rear surface of the at least one plate in the flow direction or offset from the front surface of the at least one plate in an opposite direction.