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1 – 3 of 3The purpose of this paper is to define reliability requirements to be imposed on electric engines to assure similar or higher value of mean time between failures (MTBF) for mixed…
Abstract
Purpose
The purpose of this paper is to define reliability requirements to be imposed on electric engines to assure similar or higher value of mean time between failures (MTBF) for mixed piston-electric propulsion configurations when compared to classic and unconventional piston engine configurations.
Design/methodology/approach
Reliability estimation was done using mathematical model of safety of light aircraft commercial operations. The model was developed on the basis of Federal Aviation Administration and National Transport Safety Board data. The analysis was conducted for numerous piston and electric configurations. It allowed comparison of selected solutions and definition of relation between electric engine MTBF and MTBF calculated for entire mixed piston-electric propulsion system.
Findings
It was found that, from reliability point of view, mixed piston-electric engine propulsion is attractive alternative for classic single- and twin-piston configuration. It would allow to at least doubling of MTBF for propulsion without increase of operational cost.
Practical implications
Rationale behind exploiting electric propulsion in aviation is provided. Relation between electric engine reliability and entire propulsion reliability was identified and defined. Minimum requirements concerning MTBF value for electric engine application in aviation was assessed. Conclusions from this study can be used for definition of requirements for new aircraft and by the regulatory authorities.
Originality/value
Originality consists in use of real accident statistics included in mathematical model of safety for assessment of MTBF for various classic and novel piston and piston-electric engine configurations of light aircraft. Output from the study can be exploited by the industry.
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Bartosz Dziugiel, Anna Maria Mazur, Adam Liberacki, Piotr Ginter, Agata Utracka, Sylwester Wyka, Vittorio Di Vito and Aniello Menichino
Process of building and then implementation of integrated multimodal, passenger-centred and predominantly sustainable transport system will require a specific effort to be input…
Abstract
Purpose
Process of building and then implementation of integrated multimodal, passenger-centred and predominantly sustainable transport system will require a specific effort to be input in preparation, especially if it covers new entrants like passenger Urban Air Mobility. This paper aims to address the first step which is the identification of barriers to be overcome to turn the concept into reality.
Design/methodology/approach
Comparison of the current state-of-the-art in transportation, Information and Communication Technologies as well as other city planning domains to the forecasted ecosystem, described in the form of scenarios where base for definition of necessary actions, challenges as well as potential barriers and obstacles were identified and thoroughly specified.
Findings
Barriers grouped in five categories: policy, digitalisation, transportation technologies, integration technologies and passengers’ needs allow for formulation of the relevant roadmaps defining optimal development path towards fully integrated multimodal, passenger-centred and sustainable transport system.
Research limitations/implications
Conclusions can be a starting point in studies towards development of roadmap for implementation of truly integrated municipal transport system both sharing the resources as well as high-level objectives.
Practical implications
Conclusions can be exploited in various areas starting from preparation of strategies in cities aspirating to be smart, through definition of technology development priorities by relevant agencies ending with industry actors looking for better trimming their business.
Originality/value
The identified barriers as derived from detailed investigation enable deep insight into the total transport system vision in which Urban Air Mobility integrated within urban mobility ecosystem is considered as game-changing factor having large potential to contribute to both making cities smart and sustainable.
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Ali Dinc and Murat Otkur
The purpose of this study is to perform the preliminary design, flight performance and exhaust emissions calculations of a piston engine powered unmanned aerial vehicle (UAV…
Abstract
Purpose
The purpose of this study is to perform the preliminary design, flight performance and exhaust emissions calculations of a piston engine powered unmanned aerial vehicle (UAV) during a flight cycle which consists of multiple flight altitudes and airspeeds.
Design/methodology/approach
A genuine computer model in Matlab/Simulink was developed to predict the size and weight of UAV and piston engine (using Avgas 100LL fuel) performance together with exhaust emissions in an iterative process.
Findings
The amount of emitted exhaust gases including carbon dioxide, carbon monoxide, hydrocarbons and nitrogen oxides were calculated in a typical UAV mission profile as a whole and also divided into mission flight segments.
Research limitations/implications
Emissions were calculated based on fuel flow and engine speed inputs based on ground test data for emission indices. Test data for emission indices was very limited.
Practical implications
As UAV utilization has been increasing around the world, this study presents important and noticeable results on the emissions that need to be considered for environmental purposes.
Originality/value
In literature, emission prediction studies for UAVs are very rare. In fact, UAVs typically have quite different flight speeds and altitudes than regular manned aircraft and emissions change with speed and altitude. Additionally, unlike manned aircraft, UAVs can fly more than 24 h with different operation characteristics. The originality of this study presents the emission predictions of a piston engine UAV which flies with a significantly different mission profile than a manned aircraft.
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