Fig. 1: Experimental setup and dataset.

a Experimental setup to study the response of the global vortex shedding mode in the wake of a D-shaped bluff body with a rectangular base, subject to spanwise-constant and time-periodic Coanda blowing at Reynolds number Re = 5.62 × 10⁴ based on the free-stream velocity U_∞ and body height H. Time-resolved pressure measurements are obtained from five sensors located along the mid-span of the rear face of the body. Signals are weighted by  ±1 and averaged to get the antisymmetric pressure average x(t) that characterizes the global mode amplitude response. b Normalized power spectral density (PSD) of x(t) in the unforced case, showing the natural frequency ω₀, and periodically forced at a frequency ω_f = 2ω₀. The axis Ω denotes the frequency content of the response. c Panels show the PSD of the time-series of x(t) as a function of excitation frequencies ω_f, for two types of actuation, symmetric and antisymmetric, and three forcing amplitudes ε.