HAWT: FWH Acoustic Model

Acoustic (FWH) Investigation on a HAWT, ANSYS Fluent CFD Simulation Tutorial

Description

This project investigates the acoustic performance of a horizontal axis wind turbine (HAWT), examining the noise it generates at multiple points throughout its surrounding domain. The simulation runs in a transient state using ANSYS Fluent, with the turbine rotating at 7 rad/s about its horizontal axis while an incoming air stream approaches at 15 m/s. Several monitoring points positioned both upstream and downstream of the turbine were selected for detailed noise investigation.

The acoustic results from this project are directly comparable to the companion study, "Acoustic (Broadband) Investigation on a HAWT, ANSYS Fluent CFD Simulation Tutorial", which solves the same underlying model using the Broadband Noise Source method instead — giving learners a direct side-by-side comparison of two distinct aeroacoustics prediction approaches applied to identical turbine conditions. In this FWH-based setup, monitoring points are defined through the Acoustic Model–Define Receivers tab, while the noise source itself — the turbine's blade surface — is selected through the Acoustic Model–Define Sources tab.

The geometry was designed in Design Modeler and meshed in ANSYS Meshing using tetrahedral elements, totaling approximately 2,500,000 elements.

Methodology

Acoustic behavior was modeled using the Ffowcs Williams-Hawkings (FWH) acoustic model, while turbine rotation was captured using the Moving Reference Frame (MRF) method applied within the Cell Zone Conditions. Turbulence was resolved using the k-ω SST model.

Conclusion

The acoustic results extracted at each defined receiver point include Surface dpdt RMS, static pressure, and sound pressure level (dBA), among other parameters. Results show the Surface dpdt RMS parameter increasing toward the blade edges farther from the hub, consistent with the higher local velocity magnitude and stronger interaction with the incoming wind flow in those regions.

These results can be directly compared against the companion Broadband-based study referenced above, since both solve the identical turbine model using different acoustic prediction methods. The full set of resulting contours, plots, pathlines, and FFT spectra are provided as accompanying figures, offering a comprehensive view of the turbine's acoustic signature across the surrounding domain.