A Physics-Based Multidisciplinary Approach for the Preliminary Design and Performance Analysis of a Medium Range Aircraft with Box-Wing Architecture

Abstract

The introduction of disruptive innovations in the transport aviation sector is becoming increasingly necessary. This is because there are many very demanding challenges that the transport aviation system will have to face in the years ahead. In particular, the reduction in pollutant emissions from air transport, and its impact on climate change, clearly must be addressed; moreover, sustainable solutions must be found to meet the constantly increasing demand for air traffic, and to reduce the problem of airport saturation at the same time. These three objectives seem to be in strong contrast with each other; in this paper, the introduction of a disruptive airframe configuration, called PrandtlPlane and based on a box-wing lifting system, is proposed as a solution to face these three challenges. This configuration is a more aerodynamically efficient alternative candidate to conventional aircraft, introducing benefits in terms of fuel consumption and providing the possibility to increase the payload without enlarging the overall aircraft wingspan. The development and analysis of this configuration, applied to a short-to-medium range transport aircraft, is carried out through a multi-fidelity physics-based approach. In particular, following an extensive design activity, the aerodynamic performance in different operating conditions is investigated in detail, the structural behaviour of the lifting system is assessed, and the operating missions of the aircraft are simulated. The same analysis methodologies are used to evaluate the performance of a benchmark aircraft with conventional architecture, with the aim of making direct comparisons with the box-wing aircraft and quantifying the performance differences between the two configurations. Namely, the CeRAS CSR-01, an open-access virtual representation of an A320-like aircraft, is selected as the conventional benchmark. Following such a comparative approach, the paper provides an assessment of the potential benefits of box-wing aircraft in terms of fuel consumption reduction and increase in payload capability. In particular, an increase in payload capability of 66% and a reduction in block fuel per pax km up to 22% is achieved for the PrandtlPlane with respect to the conventional benchmark, while maintaining the same maximum wingspan.

A Conceptual Design Methodology for e-VTOL Aircraft for Urban Air Mobility

“…To compute structural and system weight, the tool FLOPS developed by NASA has been used [60]: According to [60], structural weight includes wings, tails, fuselage, nacelle and paint; system weight considers control surfaces actuators, instruments, avionics, anti-icing and furnishing. It is worth noting that the classical model for cantilever wings overestimates the structural mass of the box-wing architecture [75][76][77][78], so the results reported in this paper (e.g., estimation of MTOW) are conservative. This tool is versatile since it can be used for aircraft ranging from general aviation to transport aircraft categories; in this paper, the general aviation category has been selected, since the weight formulation, adopted in this paper and described in FLOPS, have been specifically derived for general aviation aircraft category.…”

“…• the possibility to exploit the advantages of the box-wing, i.e., the minimization of induced drag for given wingspan and lift, in several ways depending on the given priorities and needs: o to reduce the energy consumption for assigned payload-range and wingspan; o to enhance transport capabilities (payload and/or range) for assigned wingspan, as highlighted by the results of the PARSIFAL project [76]; o to reduce the wingspan for assigned payload-range [77].…”

A Parametric Approach for Conceptual Integration and Performance Studies of Liquid Hydrogen Short–Medium Range Aircraft

“…where all quantities are relative to the gaseous phase, Nu is the Nusselt number for the natural convection inside the gaseous H 2 , h g is the heat transfer coefficient of the phenomenon, H g is the level of the gas inside the tank, expressed as distance from the top of the tank, and K is the thermal conductivity of the gaseous phase. As for assumptions (a), (b), and (c), the total internal thermal resistance is computed as in Equation (45), where S l and S g are the tank surfaces in contact with the liquid and gaseous phase, respectively.…”

A Parametric Approach for Conceptual Integration and Performance Studies of Liquid Hydrogen Short-Medium Range Aircraft

“…Airbus 320 or Boeing 737 family craft, while complying with the same airport constraints and, above all, reducing the fuel consumption per passenger-kilometre ( [43]). The designed aircraft has a box-wing architectures with the following main features: a number of passengers equal to 308, 66% more than the conventional competitor; a wingspan equal to 36 metres, and compatible with ICAO category 'C' airport aprons ([44]); a maximum reduction in block fuel per passenger-kilometre equal to 22% compared to the conventional competitor ( [45]). Figure 1 presents the final configuration of the PAR-SIFAL box-wing aircraft, whereas its main characteristics are reported in Table 6; for further details on the study and design of the box-wing aircraft developed within the PARSI-FAL project, please refer to [12], [43] and [45].…”

“…The designed aircraft has a box-wing architectures with the following main features: a number of passengers equal to 308, 66% more than the conventional competitor; a wingspan equal to 36 metres, and compatible with ICAO category 'C' airport aprons ([44]); a maximum reduction in block fuel per passenger-kilometre equal to 22% compared to the conventional competitor ( [45]). Figure 1 presents the final configuration of the PAR-SIFAL box-wing aircraft, whereas its main characteristics are reported in Table 6; for further details on the study and design of the box-wing aircraft developed within the PARSI-FAL project, please refer to [12], [43] and [45]. Table 6, in addition to reporting the main characteristics of the box-wing aircraft used as a baseline for this LH 2 propulsion integration study, also reports how this integration was achieved by modifying the reference aircraft.…”