The NOVAIR project studies how hybrid/electric aircraft configurations can be designed more efficiently. The use of several small, electrically powered propellers can increase efficiency, but this leads to interaction effects that must first be studied, before we are able to say anything about the aircraft.
The set-up was created to study the aerodynamic interaction between multiple propellers and a wing with flap. This interaction is important for the efficiency of the system, and is being studied as part of a European research project aimed at hybrid electric aircraft with distributed propulsion.
The model has been tested in the 2.25 m x 3 m low-velocity wind tunnel at DNW in the Noordoostpolder. The tests were carried out at a wind velocity of 108 – 144 km/h, and the propellers were rotated between 6,500 and 11,000 rpm. The model was installed on an external balance to measure the forces on the wing, and the propeller forces were measured with an internal force sensor. The pressure holes have been used to record the effect of the propellers on the pressure distribution on the wing. In addition, a microphone array was used to measure the sound of the system.
