A Correlation Study Between Aerodynamic Structural Changes and Aerodynamic Noise Characteristics of Archimedes Spiral Wind Turbines

This paper investigates the impact of aerodynamic structural changes on the aerodynamic noise of Archimedes spiral wind turbines (ASWTs) using experimental and numerical research methods. Both parts of the experimental work are validated based on the prototype ASWT, with the working conditions consistent with the numerical calculation conditions. The aerodynamic noise of the ASWT before and after modification is numerically simulated by combining Large Eddy Simulation (LES) with the Ffowcs Williams-Hawkings (FW-H) method, which converts internal flow field information into acoustic field information. The results demonstrate that the improved ASWT exhibits reduced high-frequency discrete noise in the 400 to 1000 Hz range at $TSR=2$. Specifically, the Sound Pressure Levels (SPLs) of the quadrupole noise source near 471 Hz and 671 Hz for the prototype ASWT are 100.15 dB and 112.90 dB, respectively, while the corresponding SPLs near 471 Hz and 679 Hz for the retrofitted ASWT are 57.68 dB and 63.29 dB, respectively. These represent reductions of 42.47 dB and 49.61 dB, respectively. Additionally, the predicted Overall Sound Pressure Levels (OASPLs) of the ASWT at locations 8 and 9 are 16.82 dB and 38.22 dB lower before and after modification, respectively. These findings not only improve the aerodynamic efficiency of ASWTs but also lay a solid foundation for the subsequent study of their acoustic propagation characteristics. This is of significant importance for future research on wind turbine miniaturization.