Effects of rotating frame turbulence and dynamic stall on gust response of helicopter blades

Rotating frame turbulence, or RFT, refers to the actual turbulence experienced by the helicopter blades and requires noneulerian description and rotational sampling of measurements. In the stationary case of axial flight, as investigated earlier, its spectra has peaks centered at integer multiples of rotational speed P, as in wind turbines. In forward flight, as investigated here, its instantaneous or frequency-time spectra has split peaks centered at P/2, P, 3P/2, 2P etc. Though nonstationary, it is wide sense cyclostationary in that its autocorrelation function...