نوع مقاله : مقاله پژوهشی
موضوعات
عنوان مقاله English
نویسندگان English
Underwater acoustic pollution generated by ship propellers is a significant environmental concern, making accurate prediction during the design phase crucial for mitigating negative impacts. This study investigates the hydroacoustic performance of the four-bladed INSEAN E779A marine propeller under non-cavitating conditions using a hybrid computational fluid dynamics (CFD) model. This approach combines unsteady Reynolds-averaged Navier-Stokes (URANS) equations with the Ffowcs Williams–Hawkings (FW-H) acoustic analogy to simulate turbulent flow and subsequently predict the far-field noise propagation. The propeller operates at a constant rotational speed of n=720 RPM and an advance speed of V=1.3 m/s, resulting in an advance coefficient of J=0.49. To accurately map the sound pressure level (SPL), a hydrophone array comprising 144 receivers was strategically positioned within the computational domain. Results indicate that the near-field hydrophones record a higher SPL due to severe turbulence, while these values decrease in the far-field due to increased distance and turbulent dissipation. Spectral analysis based on 12 different angles revealed that discrepancies at the second blade-passing frequency harmonic (k=2) are relatively minor. However, at the third and fourth harmonics, angular divergence increases, with some angles showing maximum deviations of up to 6 decibels above or below the mean value. This research establishes a robust foundation for noise model validation and the development of technologies for optimizing marine propulsion systems to reduce underwater acoustic pollution by providing rich data on the spatial distribution of acoustic propagation
کلیدواژهها English
