Numerical Investigation of UAV Propeller Aeroacoustics in Low-Reynolds Number Hovering Flows

Afshari, Abbas; Jafari Nia, Reza; Ragani Lamouki, Jaber

Numerical Investigation of UAV Propeller Aeroacoustics in Low-Reynolds Number Hovering Flows

Document Type : Original Article

Authors

Abbas Afshari ¹

Reza Jafari Nia ²

Jaber Ragani Lamouki ³

¹ Department of Aerospace Engineering, Shahid Sattari Aeronautical University of Science and Technology, Tehran, Iran

² M.Sc. in Aerospace Engineering, Department of Aerospace Engineering, Shahid Sattari Aeronautical University of Science and Technology, Tehran, Iran

³ P h.D student/Department of Mechanical Engineering, Ferdowsi University of Mashhad

Abstract

This study presents a numerical analysis of a UAV propeller's aeroacoustic behavior under hovering conditions. The Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations for incompressible flow were solved using ANSYS Fluent, with turbulence modeled using the k-ω SST approach. Far-field noise prediction was performed employing the Ffowcs Williams-Hawkings (FW-H) acoustic equation. Static pressure contours revealed extensive low-pressure regions on the blade's upper surface, particularly near the leading edge at the tip, significantly contributing to both thrust generation and loading noise. Surface pressure fluctuations were most pronounced along the leading edge, diminishing toward the trailing edge, suggesting the leading edge as the primary broadband noise source due to turbulent interaction with preceding blades. Far-field analysis showed dominant tonal noise at 100 Hz and its harmonics, with higher-order blade passing frequencies exhibiting near-linear attenuation. Directivity patterns indicated negligible tonal noise at 0° and 15° (suction side) and 165° and 180° (wake side) polar angles, while broadband noise decreased and tonal noise intensified at 90°.

Keywords

Aerodynamic Noise

Aeroacoustics

Computational Fluid Dynamics (CFD)

UAV propeller