General Aviation Propeller-Airframe Integration Simulations

Engineering Method to Estimate the Blade Loading of Propellers in Nonuniform Flow

“…An azimuthal variation in the advance ratio has a number of consequences. First, the propeller rotation makes the loads on the blade periodic, typically leading to additional noise [2,22,23], fatigue loads on the blades, and vibrations to the airframe [24]. Second, in-plane forces and moments are generated [25], which alter the trim condition and stability characteristics of the aircraft: in particular, for propellers at a relatively large distance to the aircraft's center of gravity [1,[26][27][28].…”

“…For example, local disturbances, such as the propeller encountering a wake or vortex, have a negligible to a small effect on the mean propeller forces; whereas they do cause significant unsteady loads and noise [29][30][31][32][33][34][35]. Asymmetric inflow, such as a propeller at a nonzero angle of attack or a propeller operating in the upwash or downwash of a wing, only changes the propeller performance slightly but still leads to significant unsteady loads and nonnegligible in-plane forces [24,[36][37][38][39][40][41][42]. Moreover, quasi-axisymmetric inflows covering a large part of the propeller disk, such as a swirling inflow to a wingtipmounted pusher-propeller or a boundary-layer inflow, have shown to alter the propeller efficiency [6,[43][44][45].…”