Analysis of influencing factors and prediction of aeroacoustic noise induced by cruise chimney exhaust pipelinene

Objectives This study analyzes the influencing factors of the aeroacoustic noise of cruise ship chimney exhaust pipelines, and predicts the noise level in the open area of a domestic cruise ship.

Methods A hybrid approach combining Large Eddy Simulation and Lighthill Analogy is used to conduct a numerical simulation of the pipeline’s aeroacoustic noise under the actual working conditions of a cruise ship. The impacts of the inlet flow rate, outlet pressure, cross-section shape and bending angle on the aerodynamic noise are studied. A real-size cruise ship chimney exhaust pipeline model is then established to analyze the main noise sources and predict the noise level in the open areaa.

Results The results show that the larger the inlet velocity and bending angle, the greater the aeroacoustic noise. Furthermore, the aeroacoustic noise of a pipeline with a zero pressure-outlet is greater than that with a non-zero pressure-outlet. It is also found that the aeroacoustic noise of a rectangular cross-sectional pipeline is marginally smaller than that of a circular one. In addition, the narrowband peak frequency decreases as the bending angle increases. Except for the chimney outlet, the noise level in the open area is low.

Conclusions This study has significant reference value for controlling the aeroacoustic noise of cruise ship chimney exhaust pipelines and improving passenger comfort in open areas.