Investigating the Performance of Longitudinal Groove on Noise Reduction in a NACA0015 Hydrofoil Using Computational Fluid Dynamics

Nowadays, hydrodynamic noise reduction in hydrofoils is of great importance due to their wide applications in marine industries, submarines and water systems. One of the modern methods for reducing this noise is the use of longitudinal grooves on the surface of the hydrofoil. In this study, the effect of longitudinal grooves on the reduction in noise generated around a NACA0015 hydrofoil was investigated. For this purpose, numerical methods based on computational fluid dynamics (CFD) and acoustic analysis using ANSYS Fluent 2024 R1 software were used. The Fuchs–Williams and Hawkings (FW-H) acoustic model was used for acoustic analysis. The results obtained from the hydrofoil without grooves and the hydrofoil equipped with longitudinal grooves were compared. In total, 11 numerical noise reading stations were installed around the hydrofoil to calculate the noise in two modes with and without grooves. The results show that the use of longitudinal grooves reduces the flow turbulence in the area near the hydrofoil surface and, as a result, prevents the formation of large and unstable vortices. This leads to a significant reduction in hydrodynamic noise, especially at low and medium frequencies. This study shows that the appropriate design of longitudinal grooves on the NACA0015 hydrofoil can be used as an effective solution to reduce hydrodynamic noise. The findings of this research can be the basis for the development of quieter hydrofoils in industrial and military applications. The results show that at low frequencies (up to approximately 10 Hz), the noise intensity of the ungrooved hydrofoil is higher than that of the grooved hydrofoil, but in the frequency range of 10 to 20 Hz, the noise intensity of the grooved hydrofoil increases significantly and exceeds that of the ungrooved hydrofoil.