Aerodynamic Investigation of the High-Lift Performance of a Propeller-Driven Regional Transport Aircraft with Distributed Propulsion

Abstract

Increased high-lift capabilities due to propeller slipstream, i.e. slipstream deflection, is seen to be one of the main benefits of distributed propulsion, as it may lead to a reduction in the main wing size and thus to reduced drag in cruise flight and/or reduced system weight and complexity. The presented work assesses the potential of distributed propulsion on the high-lift capabilities of a novel transport aircraft design from an aerodynamic point of view. The assessment is based on a regional propeller-driven transport aircraft designed within the European IMOTHEP project. Based on the initial aircraft design, a sensitivity study on the number of propellers and propeller positions with regards to the maximum lift coefficient under take-off conditions has been performed. Moreover, adjustments to the nacelle design and the propulsor integration have been investigated. The study indicates significant increases in the maximum effective lift coefficient in take-off of up to +42% due to slipstream deflection. The increase is thereby strongly dependent on the number of propellers and the propeller positions.

A Review of Novel and Non-Conventional Propulsion Integrations for Next-Generation Aircraft

“…In ref. [165] the effects on the maximum lift coefficient of the number of propellers and their relative position to the wing are investigated on two different aircraft. Regarding the high-lift system, a single slotted flap is considered, the propellers are distributed along the wingspan with a clearance (i.e., the distance between the tips of two consecutive propellers) equal to 18% of the propeller diameter.…”