Review of unconventional aircraft design concepts

1988 ◽  
Vol 25 (5) ◽  
pp. 385-392 ◽  
Author(s):  
Roy H. Lange
Keyword(s):  
Aircraft Design ◽  
Design Concepts ◽  
Unconventional Aircraft

scholarly journals Synergistic Technology Combinations for Future Commercial Aircraft Using Liquid Hydrogen

2020 ◽  
Author(s):  
Pavlos Rompokos ◽  
Andrew Rolt ◽  
Devaiah Nalianda ◽  
Askin T. Isikveren ◽  
Capucine Senné ◽  
...  
Keyword(s):  
Selection Process ◽  
Operating Cost ◽  
Integrated Design ◽  
Aircraft Design ◽  
Liquid Hydrogen ◽  
Second Phase ◽  
Commercial Aircraft ◽  
Design Concepts ◽  
Distributed Propulsion ◽  
Body Design

Abstract Liquid hydrogen (LH2) has long been seen as a technically feasible fuel for a fully sustainable greener aviation future. The low density of the cryogenic fuel would dictate the redesign of commercial aircraft to accommodate the large tanks, which are unlikely to be integrated within the whole internal volume of the wing. In the ENABLEH2 project, the morphological aspects of a LH2 aircraft design are discussed and a methodology for rapid concept comparative assessment is proposed. An exercise is then carried on to down-select short-to-medium range (SMR) and long-range (LR) concepts, able to carry 200 passengers for 3000 nmi and 414 passengers for 7500 nmi respectively. The down-selection process was split into two phases with the first considering 31 potential airframe architectures and 21 propulsion-system arrangements. The second phase made the final down-selections from a short-list of nine integrated design concepts that were ranked according to 34 criteria, relating to operating cost, revenue, noise and safety. Upon completion of the process, a tube and wing design with the tanks integrated into extended wing roots, and a blended-wing-body design were selected as the best candidates for the SMR and LR applications respectively. Both concepts feature distributed propulsion to maximise synergies from integrating the airframe and propulsion systems.

Experimental Quantification of Fan Rotor Effects on Inlet Swirl Using Swirl Distortion Descriptors

2017 ◽  
Author(s):  
Dustin J. Frohnapfel ◽  
Walter F. O’Brien ◽  
K. Todd Lowe
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Aircraft Design ◽  
Small Scale ◽  
Commercial Aircraft ◽  
Flow Angle ◽  
Turbofan Engines ◽  
Design Concepts ◽  
Significant Research ◽  
Inlet Swirl

The prominence of highly integrated engine/airframe architectures in modern commercial aircraft design concepts has led to significant research efforts investigating the use of conventional turbofan engines in unconventional installations where severe inlet distortions can arise. In order to determine fan rotor capabilities for reducing or eliminating a complex inlet swirl distortion, an experimental investigation using a StreamVane™ swirl distortion generator was conducted in a turbofan engine research platform. Three-dimensional flow data collected at two discrete planes surrounding the fan rotor indicated that the intensity of the swirl distortion was decreased by the fan rotor; however, substantial swirl distortion effects remained in the fan exit flow. Flow angle magnitudes and swirl intensity decreased by approximately 30–40% across the fan rotor, while the presence of large-scale features within the distortion profile was nearly eliminated. Secondary flow streamlines indicated that small-scale features of the distortion were less affected by the rotating component and remained coherent at the fan rotor outlet plane. These results led to the conclusion that swirl distortion survived interactions with the fan rotor, leading to off-design conditions cascading through downstream engine components.

scholarly journals Synergistic Technology Combinations for Future Commercial Aircraft Using Liquid Hydrogen

2021 ◽  
Author(s):  
Pavlos Rompokos ◽  
Andrew Rolt ◽  
Devaiah Nalianda ◽  
Askin T. Isikveren ◽  
Capucine Senné ◽  
...  
Keyword(s):  
Selection Process ◽  
Operating Cost ◽  
Integrated Design ◽  
Aircraft Design ◽  
Liquid Hydrogen ◽  
Second Phase ◽  
Commercial Aircraft ◽  
Design Concepts ◽  
Distributed Propulsion ◽  
Body Design

Abstract Liquid hydrogen (LH2) has long been seen as a technically feasible fuel for a fully sustainable greener aviation future. The low density of the cryogenic fuel would dictate the redesign of commercial aircraft to accommodate the large tanks, which are unlikely to be integrated within the whole internal volume of the wing. In the ENABLEH2 project, the morphological aspects of a LH2 aircraft design are discussed and a methodology for rapid concept comparative assessment is proposed. An exercise is then carried on to down-select short-to-medium range (SMR) and long-range (LR) concepts, able to carry 200 passengers for 3000 nmi and 414 passengers for 7500?nmi respectively. The down-selection process was split into two phases with the first considering 31 potential airframe architectures and 21 propulsion-system arrangements. The second phase made the final down-selections from a short-list of nine integrated design concepts that were ranked according to 34 criteria, relating to operating cost, revenue, noise and safety. Upon completion of the process, a tube and wing design with the tanks integrated into extended wing roots, and a blended-wing-body design were selected as the best candidates for the SMR and LR applications respectively. Both concepts feature distributed propulsion to maximise synergies from integrating the airframe and propulsion systems.

scholarly journals Experimental Quantification of Fan Rotor Effects on Inlet Swirl Using Swirl Distortion Descriptors

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Dustin J. Frohnapfel ◽  
K. Todd Lowe ◽  
Walter F. O'Brien
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Aircraft Design ◽  
Small Scale ◽  
Commercial Aircraft ◽  
Flow Angle ◽  
Turbofan Engines ◽  
Design Concepts ◽  
Significant Research ◽  
Inlet Swirl

The prominence of highly integrated engine/airframe architectures in modern commercial aircraft design concepts has led to significant research efforts investigating the use of conventional turbofan engines in unconventional installations where severe inlet distortions can arise. In order to determine fan rotor capabilities for reducing or eliminating a complex inlet swirl distortion, an experimental investigation using a StreamVaneTM swirl distortion generator was conducted in a turbofan engine research platform. Three-dimensional (3D) flow data collected at two discrete planes surrounding the fan rotor indicated that the intensity of the swirl distortion was decreased by the fan rotor; however, substantial swirl distortion effects remained in the fan exit flow. Flow angle magnitudes and swirl intensity (SI) decreased by approximately 30–40% across the fan rotor, while the presence of large-scale features within the distortion profile was nearly eliminated. Secondary flow streamlines indicated that small-scale features of the distortion were less affected by the rotating component and remained coherent at the fan rotor outlet plane. These results led to the conclusion that swirl distortion survived interactions with the fan rotor, leading to off-design conditions cascading through downstream engine components.

High resolution at low voltage: A new approach

1989 ◽  
Vol 47 ◽  
pp. 76-77
Author(s):  
Arthur V. Jones
Keyword(s):  
Low Voltage ◽  
Emission Sources ◽  
New Approach ◽  
Design Concepts ◽  
Probe Diameter ◽  
Low Voltage Operation ◽  
Sufficient Intensity ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Immersion Type

With the introduction of field-emission sources and “immersion-type” objective lenses, the resolution obtainable with modern scanning electron microscopes is approaching that obtainable in STEM and TEM-but only with specific types of specimens. Bulk specimens still suffer from the restrictions imposed by internal scattering and the need to be conducting. Advances in coating techniques have largely overcome these problems but for a sizeable body of specimens, the restrictions imposed by coating are unacceptable.For such specimens, low voltage operation, with its low beam penetration and freedom from charging artifacts, is the method of choice.Unfortunately the technical dificulties in producing an electron beam sufficiently small and of sufficient intensity are considerably greater at low beam energies — so much so that a radical reevaluation of convential design concepts is needed.The probe diameter is usually given by

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