1,721,081 research outputs found
Preliminary Safety Assessment for a VTOL hypersonic transportation system aimed at performing parabolic flights
No full textThis paper proposes a methodology for the safety assessment suitable for the conceptual design phase, especially conceived to support the design of very innovative transportation systems. In particular, this paper provides the readers with an innovate integrated approach that allows the engineers to perform high-level safety evaluations, usually carried out exploiting incidents statistics that are clearly not currently applicable for new aerial vehicles such as spaceplanes. In particular, this article proposes the safety assessment of a single-stage hypersonic spaceplane aimed at performing parabolic suborbital flights and equipped with a dual propulsion system that can enable it to perform vertical take-off and landing in non-tail-sitting position
The advantage of a hybrid piston prop aircraft
No full textThe aim of this work is to present the design of a more environmental friendly aircraft that complies with existent and future emission regulations. Recent Market Outlooks were examined and a single engine piston prop was selected as case study. Matching Charts were used to estimate hybridization degree, meaning the ratio between the power provided by the electric motors and the total amount of power. This method allowed the over-boost advantage to be highlighted and pointed out secondary benefits of hybrid Piston Prop. Furthermore, the zero-emission taxi possibility was evaluated. Both fuel savings forecast or safety analysis were performed, showing secondary advantages of a high hybridization degree for a single engine Piston Prop configuration. Furthermore, the additional weight related to electric motors and storage system is taken into account and state of art and innovative under-development technologies are considered. Thus, the conceptual design phase will produce many possible architectures and so, the last part of the work consists in a trade study necessary to select the optimal solution to design an innovative hybrid Piston Prop aircraf
Comparative analysis of new configurations of aircraft aimed at competitiveness, environmental compatibility and safety
Full text linkThis Ph.D. Thesis aims at suggesting a proper integrated and multidisciplinary design methodology to improve the current conceptual and preliminary design phases of breakthrough innovative aerospace products. The methodology, based on a Systems Engineering approach, is presented together with an envisaged toolchain, consisting of both commercial and ad-hoc developed software, integrated in a Model-Based Systems Engineering perspective. In addition, for the sake of clarity and for validation purposes, a specific case study has been selected and developed all along the document. The reference case-study is inspired to a real pre-feasibility study in which the research group of Politecnico di Torino, which the author of this Thesis belongs to, has been involved. The project aims at developing a suborbital vehicle able to perform parabolic flights for both scientific and touristic purposes. This kind of initiatives paves the way for the future hypersonic vehicles, because it allows to crucial enabling technologies to be tested and validated in relevant environment but with lower performances' requirements. The Thesis is articulated in seven Chapters with an introduction and conclusion sections and in each Chapter a balanced mix between theoretical investigation, mathematical model development, tool selection or development and application to the selected case study is guaranteed. This document starts reporting the major reasons why an innovative design methodology should be envisaged to deal with the increasing level of complexity in the aerospace domain. In particular, in the first Chapter, a brief overview of existing or underdevelopment initiatives related to hypersonic is reported, together with the description of the different types of mission in which the new hypersonic vehicles will be exploited. Moreover, the major issues related to the infrastructures required to operate these transportation systems are summarized. As far as operations are concerned, a short section makes the readers aware of the current under-development regulatory framework. Then, the integrated multidisciplinary design methodology is presented starting from the very high level analyses up to the sizing of the different components of the transportation system. All along the document, crucial role is played by requirements, whose management can allow a complete traceability of the different design characteristics during the overall product life-cycle. Furthermore, proper algorithms allowing to move from purely qualitative to quantitative trade-offs, are presented, with a noticeable advantage in terms of traceability and reproducibility. Eventually, further improvements of both the tool-chain and the reference case studies are envisaged for future developments
The advantages of a hybrid piston prop aircraft
Full text linkThe aim of this work is to present the design of a more environmental friendly aircraft that complies with existent and future emission regulations. Recent Market Outlooks were examined and a single engine piston prop was selected as a case study. Matching Charts were used to estimate the hybridization degree, meaning the ratio between the power provided by the electric motors and the total amount of power. This method allowed the over-boost advantage to be highlighted and pointed out secondary benefits of a hybrid Piston Prop. Furthermore, the zero-emission taxi possibility was evaluated. Both fuel savings forecast and safety analysis were performed, showing secondary advantages of a high hybridization degree for a single engine Piston Prop configuration. Furthermore, the additional weight related to electric motors and storage system is taken into account and state-of-the-art and innovative under-development technologies are considered. Thus, the conceptual design phase will produce many possible architectures; therefore, the last part of the work consists of a trade study necessary to select the optimal solution to design an innovative hybrid Piston Prop aircraf
Technology roadmaps for the development of future high-speed transportation systems
Full text linkThis paper describes the upgrade and application of Technology Roadmapping Strategy (TRIS) methodology
to propose an incremental path (i.e., a technology roadmap) towards the increase of Technology Readiness
Level (TRL) of STRATOFLY key-enabling technologies to meet the project’s goal (TRL 6 in 2035). The paper
discusses several improvements introduced within the roadmapping methodology in order to deal with future
high-speed transportation systems. In particular, basing on Space Shuttle cost data, a general framework to
assess the cost of TRL Transits for hypersonic technologies is proposed. In addition, a detailed analysis of
future activities to be performed to pursue hypersonic technologies is included, with special emphasis on the
importance of highly-integrated flight demonstrators at high TRL level in relation to involved stakeholders’
impact and needs
Possible hybrid propulsion configuration for transport jet aircraft
No full textThis research is aimed at studying the possible advantages of installing, for a hybrid propulsion aircraft, electric motors and related propellers into the dedicated supplementary nacelles. This innovative solution is different from the configuration, already studied for a regional turboprop (Chiesa et al. 2013), in which the electric motors are in the same nacelles of the internal combustion engines. As it has been expected, it offers the advantages of avoiding mechanical links between the two units and, more importantly, can also be applied to jet aircraft. In fact, the main contribution of electric motors is expected during ground operations, take-off and descent phases (i.e. at low speed), in which it can be useful to integrate the propellers or even substitute the jet engines with them. At high speed, the propellers, of course, are configured in order to reduce drag. When considering the design of a new airliner concept, a preliminary design study is necessary to optimize the location of the supplementary nacelles. The nacelles, which only hold the electrical motor, can also be considered retractable, as is usual for a RAT (Ram Air Turbine). Please note that in the hybrid propulsion context, the RAT function can be clearly allocated to the electric motor, with the advantages of optimizing drag at high speed, taking into account installation problem
Support and Maintenance Strategies for Future, Innovative and Largely Widespread Air Personal Transportation Systems
No full textThe aim of the paper is to present innovative and futuristic support and maintenance strategies applicable to a personal transportation aircraft which could be a substitution of the car in the medium-long term future. The paper, by using personal transportation aircraft as case study, presents results of simulation studies for demonstrating the effectiveness of the innovative futuristic support and maintenance strategies in a typical metropolitan scenario. Our vision is that in a medium-long term future a small but significant percentage of people, who live in the countryside, could use everyday a PTA (personal transportation aircraft) for reaching the job-place and returning home. Users of PTA will experience a significant improvement in the quality of life, moreover a reduction of traffic jam on the roads and pollutant emissions will be obtained. At the moment the authors are studying a PTA concept called MARGARET which is: Easy to be piloted, sufficiently affordable (i.e., cost equivalent to a medium-high segment car) and capable to assure a safe flight even in bad weather conditions. For landing, parking and maintenance MARGARET will exploit a net of "urban airports" located on urban ring roads near metro-stations and in the countryside near user's houses. An adequate maintenance system shall be conceived to maximize the availability of MARGARET assuring a better social and market acceptance. Our idea is applying atomized maintenance concept in conjunction with MMU (mobile maintenance units). Atomized maintenance concept allow to strongly increase availability of the aircraft by distributing long and concentrated scheduled maintenance activities on shorter daily maintenance activities. MMU's will be able to move from the "urban airports" near the city-center to the ones in the countryside (and vice-versa) by employing helicopters or vans. In this way, the MMU's could perform maintenance activities while the user is at work during the day or in the evening when the user returns home. An on-board fault prognostic system will allow to optimize MMU's operation
POSSIBLE HYBRID PROPULSION CONFIGURATION FOR TRANSPORT JET AIRCRAFT
No full textThis contribution is aimed to study the possible advantages of installing, for a hybrid propulsion aircraft, electric motors and related propellers into dedicated supplementary nacelles. This innovative solution is different if compared with the configuration, already studied for a regional turboprop (Chiesa et al. 2013), in which the electric motors are in the same nacelles of the internal combustion engines. As it has been expected, it offers the advantages of avoiding mechanical links between the two units and, more relevant, the possibility to be applied to jet aircraft too. In fact, the main contribution of electric motors is expected during ground operations, at take-off and descent phases (i.e. at low speed), so the propellers can be useful to integrate or even substitute the jet engines. At high speed, the propellers, of course, is configured in order to reduce drag. Considering the design of a new airliner concept, a preliminary design study is necessary to optimize the location of supplementary nacelles. For the nacelles configuration, which holds only the electrical motor, can also be considered a retractable installation as for RAT (Ram Air Turbine). Please note that in hybrid propulsion context, RAT function can be clearly demanded to electric motor, with the advantages of optimizing drag at high speed, taking into account installation problem
INVESTIGATIONS OF GROUND INFRASTRUCTURES FOR UAS FLIGHT MONITORING
No full textThis article deals with the investigation of on-ground infrastructures to be exploited to monitor Unmanned Aerial Systems during their operations. In particular, this work evaluates the usefulness of a radar technology to be installed in an airport facility. Simulation analyses have been carried out considering the installation of Primary Surveillance Radar, Secondary Surveillance Radar and ADS-B. Then, in order to ensure the economic viability of these infrastructures, the impact on civil aviation monitoring activities has been evaluated. Eventually, for the selected reference case, located in Northern part of Italy, the ADSB is proposed, taking also into account the results and the future trend already suggested by several other European Research projects focused on airspace integratio
- …
