Aerodynamic and Aeroacoustic Characterization of a Micro-Scale Shrouded Rotor in Ground Effect

An experimental investigation was conducted to examine the dynamic performance and acoustic emissions of a small-scale shrouded rotor hovering in the presence of Ground Effect (GE) in a fully anechoic chamber, where nine cases of ground plane locations were studied sequentially. Flow recirculation and its effects were also studied as part of a preliminary investigation. The results show that ground improves the aerodynamic performance of the shrouded rotor at distances below 1.5 rotor radius, with a pronounced increase in thrust and power coefficients, also influencing flight stability due to the unbalanced moment. This is in agreement with previous aerodynamic findings, but is now assessed with greater emphasis on both performance and noise. The far-field and near-field acoustic response is systematically measured across multiple rotor–ground separations and contrasted with the isolated case. Enhanced tonal peaks and variations in overall sound pressure levels were observed for the shielded and reflection zones with the introduction of the ground plane.