Aircraft Preliminary Design: the Windowless Concept
1. Introduction Based on market forecasts, air traffic is expected to double by next 20 years and the whole airliners fleets will be increase with about 35000 new aircraft. According to this perspective, production and management costs will play a key role, as well as green design perspective. In this context the objective of this paper is to perform a preliminary design of a short-medium range windowless aircraft, with the aim to reduce fuselage weight. A feasibility study will bring to the assessment of weight and cost reduction in consideration to the introduction of innovative screens, to give passengers the possibility to see through the fuselage itself. An analysis of pros and cons has been performed to evaluate the possibility of such introduction in next generation aircraft. 2. Methodology The proposed methodology consists in the preliminary design of a short – medium range aircraft, considering some defined design parameters and constraints. The activity will finally lead to weight reduction evaluation, in case the same aircraft will be designed windowless. The neutral hole theory is considered as reference for weight reduction estimation: in a fuselage, window holes have to be reinforced by stiffening panels, in order to reproduce a neutral hole condition, without any strain effect. They are not required in case of windowless configuration, so that all stiffening and transparent panel weights are computed and compared with the external metal sheet and added display weights. The resulting weight reduction results from that comparison multiply by a sensitivity factor. The main challenge is providing passengers with the same comforting aspect of a traditional window, avoiding any claustrophobia feeling. Since it is a psychological reaction to an uncomfortable condition, one of the most challenging solutions is to recreate a condition similar to fuselage windows, by the introduction of technologically advance displays. OLED (Organic Light Emitting Diode) screens are considered for that purpose, and the employment of auto-stereoscopy and gaze-tracking techniques are evaluated, in order to create the same window perspective. 3. Case study and results The design approach consists in the preliminary design of a short medium range aircraft, in accordance to some defined requirements (see table 1). Some existing configurations have been considered as reference, in relation to a proper market survey (e.g. AirbusA319, Boeing 737 and Sukhoi Superjet 100). The defined design parameters are considered as input for a novel study of a windowless configuration. 4. Conclusions In this paper a preliminary design of an innovative windowless aircraft has been performed, in which the introduction of advanced display will take the place of the window itself. Some key advantages have been proved, such as: fuselage weight reduction. This will lead to both fuel consumption and operating cost reduction; aircraft higher reliability; maintenance cost reduction; design commonalities between passenger and cargo configurations. The total weight reduction between a traditional and windowless configurations is evaluated about 16.5%.