Enhancing naval aviation safety: a numerical study of superstructure modifications and airwake control in NATO Generic Destroyer (NATO-GD) model

Ship airwakes, or turbulent airflows produced by the ship's superstructure, introduce significant challenges to helicopter operations on naval ships. The landing deck may experience unstable aerodynamic conditions because of these airwakes, reducing operational safety. In this study, passive flow control methods developed to reduce the impact of airwakes on landing deck. Their effectiveness was evaluated using numerical simulations. Turbulence energy, recirculation zones and reattachment length were the main subjects of the study. The aerodynamic performance of two distinct modifications at the hangar's rear edges was evaluated using a 1/50 scale model of the NATO Generic Destroyer (NATO-GD). It is found that these modifications improved flow stability, significantly reducing reattachment length and recirculation zone by up to 79%. However, the hangar volume decreased slightly, as modification B with the largest fillet radius achieved the greatest reduction in recirculation zones. Its aerodynamic effectiveness varied with wind-over-deck speed, showing the modifications exhibited enhanced aerodynamic behaviour at higher tested wind-over-deck speeds, highlighting the effectiveness of passive design changes in improving helicopter safety on naval vessels.