Aerodynamics noise control of elbow in Cruise ship ventilation systems

Ventilation noise is a key indicator for assessing the acoustic comfort of cruise ship cabins. The complex flow configuration and concentrated noise sources within the elbows make them the primary contributors to aerodynamic noise in cruise ship ventilation systems. The study focuses on optimizing cabin acoustics by analyzing rectangular elbows in cruise ship ventilation systems. A low noise elbow optimization methodology is adopted, which accounts for spatial constraints and noise reduction requirements. The research confirms that rounded elbows enhance both flow and acoustic performance. Meanwhile, the noise reduction effects plateauing at a curvature ratio of approximately 2.67. The adjoint optimization method is applied to redesign a conventional curvature ratio elbow, reducing aerodynamic noise by 4.83 dB while maintaining the original installation space. This research clarifies the impact of elbow geometry and optimized structures on flow-acoustic characteristics, providing theoretical and practical insights for low-noise design in cruise ship ventilation systems.