CFD Investigation of High-Lift Propeller Positions for a Distributed Propulsion System
Mário Firnhaber Beckers, Michael Schollenberger, Thorsten Lutz, Dustin Bongen, Rolf Radespiel, J.-L. Florenciano, David Ernesto Funes-Sebastian
Abstract
View Video Presentation: https://doi.org/10.2514/6.2022-3217.vid Aerodynamic propeller-wing interactions of a distributed propulsion system in a high-lift scenario were investigated as part of the Clean Sky 2 project DISPROP. A 2.5D CFD parameter study with steady-state RANS simulations of a wing segment and an Actuator Disk was conducted to determine sensitivities and correlations of design parameters at high angles of attack. The parameter study reveals a significant lift augmentation (about +60% at α=6°), but a decrease in propulsive efficiency (about −19% at α=6°). With increasing angle of attack, the lift augmentation effect decreases (down to about +50% at α=14°) while the propulsive efficiency decreases further (to about −31% at α=14°). The design parameter presenting the largest sensitivity towards system performance is the vertical propeller position. The distance between the propeller and the wing has a comparatively minor effect, as long as the vertical propeller position is adapted accordingly. Propulsive performance can be significantly improved by tilting the propeller downwards towards the inflow (by about +30% for θ=20° compared to a non-tilted propeller). A spanwise clustering of propellers (tip-to-tip distance ΔY_tip ≤25%D) appears to be beneficial when considering a predetermined amount of distributed propellers. Based on the parameter study, three propeller positions were selected for more detailed numerical analysis and wind tunnel experiments at Technical University of Berlin’s "GroWiKa".