Numerical Investigation of High-Lift Propeller Positions for a Distributed Propulsion System

Abstract

The aerodynamic propeller–wing interactions of a distributed propulsion system in a high-lift scenario were investigated. A computational fluid dynamics parameter study with steady-state Reynolds-averaged Navier–Stokes simulations of a wing segment and an actuator disk was conducted to determine the sensitivities and correlations of design parameters at high angles of attack. The parameter study revealed a significant lift augmentation (about at ) but a decrease in propulsive efficiency (about at ). With increasing angle of attack, the lift augmentation effect decreased (down to about at ), whereas the propulsive efficiency decreased further (to about at ). The design parameter presenting the largest sensitivity toward system performance was the vertical propeller position. The distance between the propeller and the wing had a comparatively minor effect, as long as the vertical propeller position was adapted accordingly. Propulsive performance could be significantly improved by tilting the propeller downward toward the inflow (by about for as compared to a nontilted propeller). A spanwise clustering of propellers (tip-to-tip distance of ) appears to be beneficial when considering a predetermined amount of distributed propellers.