Impact of propeller arrangement on aerodynamic performance for a high-lift distributed propulsion system

Distributed electric propulsion is an emerging research topic, with a key advantage being its potential for enhanced lift performance through aerodynamic propeller-wing interactions. To address the lack of research on the flow mechanism of distributed propulsion systems, quasi-steady Reynolds-averaged Navier-Stokes numerical simulations were conducted on a simplified 2.5D distributed propulsion system to analyze the impact of parameters such as advance ratio, spanwise propeller distance (tip-to-tip distance), and angle of attack. The parameters study revealed that achieving optimal distributed propulsion system performance requires a trade-off with propeller efficiency. At low angles of attack, propeller efficiency increases by up to 4% with increasing spanwise propeller distance. However, this trend reversed at high angles of attack. The system lift coefficient shows a maximum increase of approximately 100% compared to the isolated system. The converging flow generated by distributed propellers on the suction side of the wing contributes to lift enhancement. At high angles of attack, the small spanwise propeller distance configuration benefits mainly from the wing on the ascending blade side (P-) within the slipstream region, while the medium configuration derives lift primarily from the wing section adjacent to the ascending blade side (P-) in the non-slipstream region. The flap exhibits an inverse low-pressure distribution compared to the wing. SST-IDDES method results indicate that the spiral vortex on the suction surface of the wing on the ascending blade side contributes to increased lift for the distributed propulsion system. The study clarifies the impact of flow field structures induced by distributed propeller-wing interactions on the aerodynamic performance of distributed propulsion systems, establishing a theoretical foundation for the aerodynamic optimization of systems.