Near-field pressure and wake dynamics in aerodynamic noise control of a forced rotating cylinder

This study investigates the aerodynamic noise control mechanisms of a forced rotating circular cylinder at a subcritical Reynolds number ( upper R e equals 4.7 times 10 Superscript 4 R e = 4.7 × 10 4 Re = 4.7 × 10⁴ ) using large-eddy simulation coupled with the Ffowcs Williams–Hawkings acoustic analogy, validated by wind tunnel experiments. Five representative rotation ratios, alpha equals 0 α = 0 α =0 , 0.5 0.5 $0.5$ , 1 1 $1$ , 2 2 $2$ and 4 4 $4$ , are analysed to relate wall-pressure fluctuations and wake organisation to the radiated noise. At alpha equals 0.5 α = 0.5 α =0.5 , the natural shedding tone separates into two components, upper S t 01 almost equals 0.18 S t 01 ≈ 0.18 St₀₁≈ 0.18 and upper S t 02 almost equals 0.23