Predicted performance of the inverted joined wing scaled demonstrator

Abstract

The aim of this paper is to present the performance analysis for an inverted joined wing aircraft demonstrator. Its configuration is said to offer lower drag in comparison to conventional aircraft, resulting in L/D ratio improvement and better performance in general. Moreover, the solution with wings inverted, i.e. with the front wing located above the aft wing, seems to give an even better L/D ratio for a wider range of angles of attack. This paper aims at presenting an aeroplane‘s performance analysis, beginning from the determination of fundamental aircraft aerodynamic characteristics on the basis of wind tunnel tests, to the assessment of powered aircraft characteristics. Such an analysis will answer the question whether the proposed propulsion unit is suitable in this specific case, which means that it will determine if the climb ratio and maximum endurance are adequate. It is crucial to assess these factors before flight tests are initiated as they have a direct influence on the safety of the aeroplane. If the results of the analysis show that the current propulsion unit is not adequate, another one would be proposed taking into account that the maximum take-off weight cannot exceed 25 kg, as defined by civil regulations. Finally, several types of mission profiles are to be planned with great attention to maximum flight endurance and the energy required in batteries that needs to be reserved for emergency situations.

Keyword : joined wing, flight demonstrator, flight performance, mission profile, flight testing, electric propulsion