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1 – 10 of 31Mosab Alrashed, Theoklis Nikolaidis, Pericles Pilidis, Soheil Jafari and Wael Alrashed
Recent advancements in electrified transportation have been necessitated by the need to reduce environmentally harmful emissions. Accordingly, several aviation organisations and…
Abstract
Purpose
Recent advancements in electrified transportation have been necessitated by the need to reduce environmentally harmful emissions. Accordingly, several aviation organisations and governments have introduced stringent emission reduction targets for 2050. One of the most promising technologies proposed for achieving these targets is turboelectric distributed propulsion (TeDP). The objective of this study was to explore and identify key indicators for enhancing the applicability of TeDP in air transportation.
Design/methodology/approach
An enhancement valuation method was proposed to overcome the challenges associated with TeDP in terms of technological, economic and environmental impacts. The result indicators (RIs) were determined; the associated performance indicators (PIs) were analysed and the key RIs and PIs for TeDP were identified. Quantitative measurements were acquired from a simulated TeDP case study model to estimate the established key PIs.
Findings
It was determined that real-world TeDP efficiency could be enhanced by up to 8% by optimising the identified key PIs.
Originality/value
This study is the first to identify the key PIs of TeDP and to include a techno-economic environmental risk analysis (TERA) based on the identified key PIs. The findings could guide developers and researchers towards potential focus areas to realise the adoption of TeDP.
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Michael J. Armstrong and Christine A.H. Ross
This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and…
Abstract
Purpose
This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components.
Design/methodology/approach
The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions.
Findings
Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems.
Practical implications
The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems.
Originality/value
The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP.
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Gokcin Cinar, Elena Garcia and Dimitri N. Mavris
The purpose of this paper was to create a generic and flexible framework for the exploration, evaluation and side-by-side comparison of novel propulsion architectures. The intent…
Abstract
Purpose
The purpose of this paper was to create a generic and flexible framework for the exploration, evaluation and side-by-side comparison of novel propulsion architectures. The intent for these evaluations was to account for varying operation strategies and to support architectural design space decisions, at the conceptual design stages, rather than single-point design solutions.
Design/methodology/approach
To this end, main propulsion subsystems were categorized into energy, power and thrust sources. Two types of matrices, namely, the property and interdependency matrices, were created to describe the relationships and power flows among these sources. These matrices were used to define various electrified propulsion architectures, including, but not limited to, turboelectric, series-parallel and distributed electric propulsion configurations.
Findings
As a case study, the matrices were used to generate and operate the distributed electric propulsion architecture of NASA’s X-57 Mod IV aircraft concept. The mission performance results were acceptably close to the data obtained from the literature. Finally, the matrices were used to simulate the changes in the operation strategy under two motor failure scenarios to demonstrate the ease of use, rapidness and automation.
Originality/value
It was seen that this new framework enables rapid and analysis-based comparisons among unconventional propulsion architectures where solutions are driven by requirements.
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Hyun Dae Kim, James L. Felder, Michael T. Tong, Jeffrey J. Berton and William J. Haller
– The purpose of this article is to present a summary of recent study results on a turboelectric distributed propulsion vehicle concept named N3-X.
Abstract
Purpose
The purpose of this article is to present a summary of recent study results on a turboelectric distributed propulsion vehicle concept named N3-X.
Design/methodology/approach
The turboelectric distributed propulsion system uses multiple electric motor-driven propulsors that are distributed on an aircraft. The power to drive these electric propulsors is generated by separately located gas turbine-driven electric generators on the airframe. To estimate the benefits associated with this new propulsion concept, a system analysis was performed on a hybrid-wing-body transport configuration to determine fuel burn (or energy usage), community noise and emissions reductions.
Findings
N3-X would be able to reduce energy consumption by 70-72 per cent compared to a reference vehicle, a Boeing 777-200LR, flying the same mission. Predictions for landing and take-off NOX are estimated to be 85 per cent less than the Tier 6-CAEP/6 standard. Two variants of the N3-X vehicle were examined for certification noise and found to have International Civil Aviation Organization Chapter 4 cumulative margins of 32EPNdB and 64EPNdB.
Practical implications
It is expected that the turboelectric distributed propulsion system may indeed provide unprecedented reductions in fuel/energy consumption, community noise and landing and take-off NOX emissions required in future transport aircraft.
Originality/value
The studied propulsion concept is a step change from the conventional propulsion system and addresses growing aviation demands and concerns on the environment and energy usage.
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Michael J. Armstrong and Christine A.H. Ross
The purpose of this paper is to highlight and discuss the unique safety and protection requirements for the electrical microgrid system in a turboelectric distributed propulsion…
Abstract
Purpose
The purpose of this paper is to highlight and discuss the unique safety and protection requirements for the electrical microgrid system in a turboelectric distributed propulsion aircraft.
Design/methodology/approach
The NASA N3-X concept aircraft requirements were considered. The TeDP system was decomposed into three subsystems: turbogenerator, distribution system and propulsors. Unique considerations for each of these subsystems were identified.
Findings
The fail-safe requirements for a TeDP system require a divergence from the standard safety case used for conventional propulsion systems. Advantages in flight control and single-engine-out scenarios can be realized using TeDP. Additionally, a targeted use of energy storage and reconfigurability may enable seamless response to propulsion systems failures.
Practical implications
The concepts discussed in this paper will assist to guide the early conceptual and preliminary design and evaluation of TeDP architectures.
Originality/value
The safety case for TeDP architectures is currently immature. The work presented here acts to frame some of the major issues when designing, evaluating and verifying TeDP conceptual architectures.
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Paulas Raja Sekaran, Amir S. Gohardani, Georgios Doulgeris and Riti Singh
– This article aims to investigate a selected number of liquid hydrogen storage tank parameters in a turboelectric distributed propulsion concept.
Abstract
Purpose
This article aims to investigate a selected number of liquid hydrogen storage tank parameters in a turboelectric distributed propulsion concept.
Design/methodology/approach
In this research study, tank structure, tank geometry, tank materials and additional physical phenomenon such as hydrogen boil-off and permeation are considered. A parametric analysis of different insulation foams is also performed throughout the design process of a lightweight liquid hydrogen storage tank.
Findings
Based on the mass of boil-off and foam weight, phenolic foam exhibited better characteristics amongst the five foam insulation materials considered in this particular study.
Practical implications
Liquid hydrogen occupies 4.2 times the volume of jet fuel for the same amount of energy. This suggests that a notable tank size is expected. Nonetheless, as jet fuel weighs 2.9 times more than liquid hydrogen for the same amount of energy, this reduced weight aspect partly compensates for the increased tank size.
Originality/value
In this article, potential insulation materials for liquid hydrogen storage tanks are highlighted and compared utilizing a presented methodology.
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Ralph H. Jansen, Cheryl L. Bowman, Sean Clarke, David Avanesian, Paula J. Dempsey and Rodger W. Dyson
This paper aims to review national aeronautics and space administration (NASA’s) broad investments in electrified aircraft propulsion (EAP). NASA investments are guided by an…
Abstract
Purpose
This paper aims to review national aeronautics and space administration (NASA’s) broad investments in electrified aircraft propulsion (EAP). NASA investments are guided by an assessment of potential market impacts, technical key performance parameters, and technology readiness attained through a combination of studies, enabling fundamental research and flight research.
Design/methodology/approach
The impact of EAP varies by market and NASA is considering three markets as follows: national/international, on-demand mobility and short-haul regional air transport. Technical advances in key areas have been made that indicate EAP is a viable technology. Flight research is underway to demonstrate integrated solutions and inform standards and certification processes.
Findings
A key finding is that sufficient technical advances in key areas have been made, which indicate EAP is a viable technology for aircraft. Significant progress has been made to reduce EAP adoption barriers and further work is needed to transition the technology to a commercial product and improve the technology, so it is applicable to large transonic aircraft.
Practical implications
Significant progress has been made to reduce EAP adoption barriers and further work is needed to transition the technology to a commercial product and improve the technology, so it is applicable to large transonic aircraft.
Originality/value
This paper will review the activities of the hybrid gas-electric subproject of the Advanced Air Transport Technology Project, the Revolutionary Vertical Lift Technology Project and the X-57 Flight Demonstration Project, and discuss the potential EAP benefits for commercial and military applications. This paper focuses on the vehicle-related activities, however, there are related NASA activities in air space management and vehicle autonomy activities, as well as a breakthrough technology project called the Convergent Aeronautics Solutions Project. The target audience is people interested in EAP.
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Alik Isyanov, Alexander Lukovnikov and Artur Mirzoyan
– This paper aims to consider main challenges of development of advanced architectures of propulsion systems, i.e. distributed propulsion systems (DPS).
Abstract
Purpose
This paper aims to consider main challenges of development of advanced architectures of propulsion systems, i.e. distributed propulsion systems (DPS).
Design/methodology/approach
This paper is a comparative analysis of different types of DPS.
Findings
Mechanical driving DPS seems as more feasible in near-term outlook, and turboelectric and full electric DPS are imagined feasible in mid- and far-term outlook.
Research limitations/implications
Additional comprehensive numerical and experimental researches are needed to approve the efficiency of DPS.
Practical implications
Possible impact of installation of DPS on aeroplane fuel efficiency are shown.
Originality/value
Application of DPS on long-range aeroplanes is new a engineering solution, which may allow to meet future advanced efficiency goals.
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Peter Malkin and Meletios Pagonis
The purpose of this paper is to describe the necessity for the use of fully superconducting electrical power systems (SEPS) in future hybrid electric aircraft which facilitates…
Abstract
Purpose
The purpose of this paper is to describe the necessity for the use of fully superconducting electrical power systems (SEPS) in future hybrid electric aircraft which facilitates the use of a distributed propulsion system.
Design/methodology/approach
The paper looks at the overall design of the electric power systems for these applications and compares the design process of a more conventional power network with a fully superconducting one. The design issues and solutions in each case are then described.
Findings
The paper concludes that SEPS will give many advantages to the aircraft design and operation.
Practical implications
Significant efforts needs to be oriented towards the development of fully SEPS and dedicated facilities are required for reliable experimental data that will allow the modelling of these systems.
Originality/value
The requirement for more experimental work has not yet been considered by the Industry, as it is a general belief that these networks will behave similar to the conventional ones.
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Benjamin Schiltgen, Michael Green, Jeffrey Freeman and Andrew Gibson
This paper aims to create a terminal area operations (TAO) analysis software that can accurately appreciate the nuances of hybrid electric distributed propulsion (HEDP), including…
Abstract
Purpose
This paper aims to create a terminal area operations (TAO) analysis software that can accurately appreciate the nuances of hybrid electric distributed propulsion (HEDP), including unique failure modes and powered-lift effects.
Design/methodology/approach
The program was written in Visual Basic with a user interface in Microsoft Excel. It integrates newly defined force components over time using a fourth order Runge-Kutta scheme.
Findings
Powered-lift, HEDP failure modes and electrical component thermal limitations play significant roles on the performance of aircraft during TAO. Thoughtful design may yield better efficiency; however, care must be given to address negative implications. Reliability and performance can be improved during component failure scenarios.
Research limitations/implications
This program has and will support the investigation of novel propulsion system architectures and aero-propulsive relationships through accurate TAO performance prediction.
Practical implications
Powered-lift and HEDP architectures can be employed to improve takeoff and climb performance, both during nominal and component failure scenarios, however, reliance on powered-lift may result in faster approach speeds. High-lift and system failure behavior may also allow new approaches to design and sizing requirements.
Originality/value
This program is unique in both the public and private sectors in its broad capabilities for TAO analysis of aircraft with HEDP systems and powered-lift.
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