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 [Formula: see text] 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 [Formula: see text] at [Formula: see text]) but a decrease in propulsive efficiency (about [Formula: see text] at [Formula: see text]). With increasing angle of attack, the lift augmentation effect decreased (down to about [Formula: see text] at [Formula: see text]), whereas the propulsive efficiency decreased further (to about [Formula: see text] at [Formula: see text]). 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 [Formula: see text] for [Formula: see text] as compared to a nontilted propeller). A spanwise clustering of propellers (tip-to-tip distance of [Formula: see text]) appears to be beneficial when considering a predetermined amount of distributed propellers.