IDINTOS: the first prototype of an amphibious PrandtlPlane-shaped aircraft

This paper summarizes the main activities conducted to design, optimize and build a prototype of an innovative light amphibian. This aircraft is a “PrandtlPlane”, a particular box-wing configuration which introduces relevant advantages as increased aerodynamic efficiency and safety of flight; the research project, called IDINTOS, has been co-funded by the Regional Government of Tuscany (Italy), coordinated by the University of Pisa and carried out in 30 months by a consortium of public bodies and small private firms, starting from 2011. In this contribution an overview is given also on several aspects concerning the design, as the aerodynamic optimization, the construction and tests of three scaled models for towing tank wind tunnel and, flight tests, respectively

Aerodynamic design of a light amphibious PrandtlPlane: wind tunnel tests and CFD validation

As part of the activities carried out during the "IDINTOS" project, wind tunnel tests have been performed on a ¼ scaled model of a two seats amphibious PrandtlPlane. The present paper deals with the CFD analyses performed after such experimental activities, with the main goal of solving lateral-directional stability problems observed during wind tunnel tests. In the first part of the paper, an overview of the wind tunnel test performed is provided and some of the achieved results are discussed, underlining the aforementioned directional stability problems. The second part of the paper concerns the CFD model validation activities, consisting in the search of the models whichbest represent the wind tunnel conditions. The results of several simulations are discussed, taking the influence of the scale factor, the turbulence models and the presence of wind tunnel structures, such as the walls and the strut, into account. A detailed description of the implementation procedure adopted of the κ-ω turbulence model with fixed transition is provided. Finally, in the third part of the paper, the chosen CFD model is used to find a solution for the improvement of the directional stability. The achieved result are presented and some information about the adoption of the selected solution on a scaled radio-controlled flying model are reported

A new ultralight amphibious PrandtlPlane: preliminary CFD design of the hull

This paper describes the preliminary CFD analyses of a ultralight amphibious PrandtlPlane, performed in order to the define the hull configurations to be studied in a subsequent towing tank test campaign. By taking the Italian regulations on ultralight aircraft into account, the effects of the main design parameters on take-off manoeuvre are studied and two hull configurations are defined. Finally, the achieved results are discussed in order to define the scale factor of towing tank test models

Tiltrotor with double mobile wing

A convertiplane structure (100), having a longitudinal axis x and a plane n orthogonal to it, comprises a main wing (120) arranged to rotate about at least one transversal rotation axis y, an auxiliary wing (130), which is located back with respect to main wing (120), and arranged to rotate about at least one transversal rotation axis y', at least two main propellers (220) located on the main wing (120), and at least two auxiliary propellers (230) located on the auxiliary wing (130). The auxiliary wing (130) is located at a vertical height higher than main wing (120). Two vertical wings (140) are also provided located in such a way that the projections on the plane n of the main wing (120), of the auxiliary wing (130) and of the vertical wings (140) shape a closed polygon, thus reducing the induced drag and increasing the overall aerodynamic efficiency

Conceptual design of PrandtlPlane civil transport aircraft

According to aircraft manufacturers and several air transportation players, the main challenge the civil aviation will have to deal with in the future is to provide a sustainable growth strategy, in order to face the growing demand of air traffic all over the world. The sustainability requirements are related to air pollution, noise impact, airport congestion, competitiveness of the air transportation systems in terms of travel time and passengers’ comfort. Among the possible ways to allow a sustainable growth of the air transportation systems, disruptive aircraft configurations have been object of study for several years, in order to demonstrate that the improvement of aircraft performance can enable the envisaged growth. This paper presents the study of a possible novel configuration called ‘‘PrandtlPlane,’’ having a box-wing layout derived from Prandtl’s ‘‘Best Wing System’’ concept. The paper deals with the definition of top level requirements and faces the conceptual study of the overall configuration, focusing on fuselage sizing as well as on the aerodynamic design of the box-wing system. This latter is designed through an optimization-driven strategy, carried out by means of a low fidelity aerodynamic tool, which simulates the flow condition in the subsonic range and introduces correction to take the transonic effects into account. Design procedures and tools are presented, showing preliminary results related to a PrandtlPlane compliant with ICAO Aerodrome Reference Code ‘‘C’’ standard, such as Airbus A320 and Boeing 737, whose wingspan is limited to 36 m. Activities and results here shown are part of the first phase of the research project ‘‘PARSIFAL’’ (Prandtlplane ARchitecture for the Sustainable Improvement of Future AirpLanes), funded by the European Commission under the Horizon 2020 Program, which aims to demonstrate that the PrandtlPlane configuration can improve aircraft payload capability, keeping their dimensions compatible with present airport infrastructures

Flight dynamics model for preliminary design of PrandtlPlane wing configuration with sizing of the control surfaces

The purpose of this paper is to present design procedures and tools for the aerodynamic optimization of a large freighter aircraft with a PrandtlPlane configuration. Suitable optimization tools have been developed and are shortly described in the paper; sensitivity analyses for high speed flight conditions have been performed, and, also, low speed performances are evaluated to provide a complete preliminary design of the PrandtlPlane freighter

Aerodynamic optimization of a large PrandtlPlane configuration

The purpose of this paper is to present design procedures and tools for the aerodynamic optimization of a large freighter aircraft with a PrandtlPlane configuration. Suitable optimization tools have been developed and are shortly described in the paper; sensitivity analyses for high speed flight conditions have been performed, and, also, low speed performances are evaluated to provide a complete preliminary design of the PrandtlPlane freighter

Preliminary transonic CFD analyses of a PrandtlPlane transport aircraft

In the framework of the PARSIFAL research project, funded by the European Community in the Horizon 2020 program, the PrandtlPlane (PrP) configuration has been proposed as an innovative alternative to the current commercial aircraft of conventional architecture; the PrP configuration development is presented in order to satisfy the future air traffic growing requirements with better performances than conventional one, in terms of fuel efficiency, safety, pollution and noise emissions. In this paper a preliminary aerodynamic investigation of the transonic behaviour of the PrP wing system is presented; this study has been carried out by means of CFD analyses, with the aim to collect relevant information and to detect the proper design and operative space, fundamental for the following aerodynamic design activity of the aircraft. Investigations have been made on macro parameters (like wing loading or cruise Mach number) and also on local critical issues. The results obtained allows to design some initial reference configurations with satisfactory cruise performance in this very initial stage of the design process

Future Aircraft and the Future of Aircraft Noise

In order to cope with increasing air traffic and the requirement to decrease the overall footprint of the aviation sector - making it more sustainably and acceptable for the whole society - drastic technology improvements are required beside all other measures. This includes also the development of novel aircraft configurations and associated technologies which are anticipated to bring significant improvements for fuel burn, gaseous and noise emissions compared to the current state and the current evolutionary development. Several research projects all over the world have been investigating specific technologies to address these goals individually, or novel - sometimes also called "disruptive" - aircraft concepts as a whole. The chapter provides a small glimpse on these activities - mainly from a point of view of recent European funded research activities like Horizon2020 projects ARTEM, PARSIFAL, and SENECA being by no-way complete or exhaustive. The focus of this collection is on noise implications of exemplary novel concepts as this is one of the most complicated and least addressed topics in the assessment of aircraft configurations in an early design stage. Beside the boundary layer ingestion concept, the design process for a blended wing body aircraft is described, a box-wing concept is presented and an outlook on emerging supersonic air transport is given