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1 – 10 of 17The purpose of this paper is to explore the possibilities of introducing a number of visionary and pioneering ideas and upcoming enabling technologies for a conceptual and…
Abstract
Purpose
The purpose of this paper is to explore the possibilities of introducing a number of visionary and pioneering ideas and upcoming enabling technologies for a conceptual and aerodynamic design of green business jet aircraft to meet various requirements within Green and N + 2 Aircraft framework, and at the same time, to meet the requirements of air transportation demand, economic growth and environmental conservation.
Design/methodology/approach
A synthesis of various aircraft design methodologies has been carried out through iterative optimization to arrive at the conceptually designed aircraft with novel concept with optimum performance within the subsonic flight regimes. Major ideas derived from D8 and other novel concepts are appropriately applied in the work, which starts with fuel efficient motivation, and followed by wing aerodynamics and other critical factors related to the design requirements and objectives.
Findings
Through a meticulous effort following the synthesized design methodologies in the conceptual design phase, a conceptual design of a quad-bubble business jets with a set of specifications that meet the green and N + 2 aircraft technology requirements and exhibit promising performances is proposed and assessed within recent aircraft technology development.
Research limitations/implications
The research work is limited to conceptual design and analytical work which should be followed by further iterative steps incorporating experiments and detailed structural and aerodynamic computations.
Practical implications
The conceptual design proposed can be utilized as a baseline for further practical step in an aircraft development project.
Social implications
The conceptual design proposed could be utilized for business and economic study for future air transportation system.
Originality/value
The work is original, incorporating review of state-of-the-art technology, environmental requirements and a synthesis of a novel product.
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Aoxiang Qiu, Weimin Sang, Feng Zhou and Dong Li
The paper aims to expand the scope of application of the lattice Boltzmann method (LBM), especially in the field of aircraft engineering. The traditional LBM is usually applied…
Abstract
Purpose
The paper aims to expand the scope of application of the lattice Boltzmann method (LBM), especially in the field of aircraft engineering. The traditional LBM is usually applied to incompressible flows at a low Reynolds number, which is not sufficient to satisfy the needs of aircraft engineering. Devoted to tackling the defect, the paper proposes a developed LBM combining the subgrid model and the multiple relaxation time (MRT) approach. A multilayer adaptive Cartesian grid method to improve the computing efficiency of the traditional LBM is also employed.
Design/methodology/approach
The subgrid model and the multilayer adaptive Cartesian grid are introduced into MRT-LBM for simulations of incompressible flows at a high Reynolds number. Validated by several typical flow simulations, the numerical methods in this paper can efficiently study the flows under high Reynolds numbers.
Findings
Some numerical simulations for the lid-driven flow of cavity, flow around iced GLC305, LB606b and ONERA-M6 are completed. The paper presents the investigation results, indicating that the methods are accurate and effective for the separated flow after icing.
Originality/value
LBM is developed with the addition of the subgrid model and the MRT method. A numerical strategy is proposed using a multilayer adaptive Cartesian grid method and its treatment of boundary conditions. The paper refers to innovative algorithm developments and applications to the aircraft engineering, especially for iced wing simulations with flow separations.
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Davide Secchi and Emanuele Bardone
Bandwagon refers to the adoption of popular ideas, thoughts, or practices. Although the inter-organizational (macro) dynamics of the phenomenon have been widely studied, its…
Abstract
Bandwagon refers to the adoption of popular ideas, thoughts, or practices. Although the inter-organizational (macro) dynamics of the phenomenon have been widely studied, its intra-organizational (micro) aspects have received limited attention. The paper presents a theoretical framework and a model that address intra-organizational aspects of bandwagon drawing on distributed cognition, social relationships, and other elements of the organizational structure such as culture and defensive routines. The analysis of simulated data from the model suggests that the phenomenon is likely to decrease with highly informal culture, promotion of advice taking and giving, low levels of distrust, strong social ties, and minimal defensive routines.
The ATF 10/20 from Electrovert (UK) is a bench‐top wave soldering system, whose competent ‘no frills’ ease of maintenance design combined with sound build quality makes it an…
Abstract
The ATF 10/20 from Electrovert (UK) is a bench‐top wave soldering system, whose competent ‘no frills’ ease of maintenance design combined with sound build quality makes it an ideal entry level machine.
Beck discusses the need to improve library and information services for the deaf community. The technological support available to libraries to serve the deaf is identified and…
Abstract
Beck discusses the need to improve library and information services for the deaf community. The technological support available to libraries to serve the deaf is identified and described. Turnkey systems are found to be lacking in applications devoted to those who cannot hear or who are hard of hearing. Other technologies, like captioned videos, TDDs, and assistive listening systems, are examined for levels of service and excellence as well as cost. Examples of technology in transition and for the future are offered, along with experiments on speech and sound. These include inner ear implants, the “data glove” experiments, and tactile translators. Technological conflicts that may arise due to one person having multiple disabilities are presented with a discussion on the prevention of dangerous or difficult situations. Possible difficulties and ways to handle opposing technologies are examined briefly. Appropriate sections of the Americans with Disabilities Act and Guidelines are grouped with the technologies that aid compliance. Additional laws are mentioned where their inclusion is appropriate. Suggested guidelines for serving the deaf/disabled community are offered for librarians working in all library types.
Jesús Manuel Fernandez Oro, Andrés Meana-Fernández, Monica Galdo Vega, Bruno Pereiras and José González Pérez
The purpose of this paper is the development of a CFD methodology based on LES computations to analyze the rotor–stator interaction in an axial fan stage.
Abstract
Purpose
The purpose of this paper is the development of a CFD methodology based on LES computations to analyze the rotor–stator interaction in an axial fan stage.
Design/methodology/approach
A wall-modeled large eddy simulation (WMLES) has been performed for a spanwise 3D extrusion of the central section of the fan stage. Computations were performed for three different operating conditions, from nominal (Q_N) to off-design (85 per cent Q_N and 70 per cent Q_N) working points. Circumferential periodic conditions were introduced to reduce the extent of the computational domain. The post-processing procedure enabled the segregation of unsteady deterministic features and turbulent scales. The simulations were experimentally validated using wake profiles and turbulent scales obtained from hot-wire measurements.
Findings
The transport of rotor wakes and both wake–vane and wake–wake interactions in the stator flow field have been analyzed. The description of flow separation, particularly at off-design conditions, is fully benefited from the LES performance. Rotor wakes impinging on the stator vanes generate a coherent large-scale vortex shedding at reduced frequencies. Large pressure fluctuations in the stagnation region on the leading edge of the vanes have been found.
Research limitations/implications
LES simulations have shown to be appropriate for the assessment of the design of an axial fan, especially for specific operating conditions for which a URANS model presents a lower performance for turbulence description.
Originality/value
This paper describes the development of an LES-based simulation to understand the flow mechanisms related to the rotor–stator interaction in axial fan stages.
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Chien-Yi Huang, Li-Cheng Shen, Ting-Hsuan Wu and Christopher Greene
This paper aims to discuss the key factors affecting the quality characteristics, such as the number of solder balls, the spread distance of residual underfill and the completion…
Abstract
Purpose
This paper aims to discuss the key factors affecting the quality characteristics, such as the number of solder balls, the spread distance of residual underfill and the completion time of the underfilling.
Design/methodology/approach
The Taguchi method is applied to configure the orthogonal table and schedule and execute the experiment. In addition, principal components analysis is used to obtain the points. Then, based on gray relational analysis and the technique for order preference by similarity to ideal solution, the closeness between each quality characteristic and the ideal solution is adopted as the basis for evaluating the quality characteristics.
Findings
The optimal parameter combination is proposed, which includes 4 dispensing (11 mg/dispensing), a “half flow” interval state, 80°C preheating module PCB board and an L-shaped dispensing path and verification testing is performed.
Originality/value
For vehicles and handheld electronic products, solder joints that connect electronic components to printed circuit boards may be cracked due to collision, vibration or falling. Consequently, solder balls are closely surrounded and protected by the underfill to improve joint strength and resist external force factors, such as collision and vibration. This paper addresses the defects caused during the second reflow process of a vehicle electronic communication module after the underfilling process.
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Emerging ‘chip‐size’packages, and bare flip‐chips, require new substrate properties if high lead count chips are tobe reliably interconnected on printed wiring boards and…
Abstract
Emerging ‘chip‐size’ packages, and bare flip‐chips, require new substrate properties if high lead count chips are to be reliably interconnected on printed wiring boards and multichip modules at low cost. Blind via holes have been shown to increase interconnect density significantly without adding layers which contribute to high cost. Until recently, the use of blind vias has been limited to high‐end applications since standard fabrication methods, either sequential lamination or controlled depth drilling, are too slow and expensive for most high volume commercial applications. To maintain a low layer count while interconnecting higher I/O packages, commercial and consumer electronics require a substrate technology which supports high speed, micro‐via hole formation. This paper describes a process for fabricating high speed micro‐vias in dimensionally stable non‐woven Aramid reinforced laminates using laser ablation technology. Laser equipment capable of producing over 100 blind micro‐via holes per second is discussed. The process steps of hole cleaning and plating are reviewed, showing how existing PWB manufacturing technologies can be used. This process is compared with other methods of generating small holes and blind vias in printed wiring boards. In addition, requirements for flip‐chip and chip‐size packages, including a coefficient of thermal expansion of <10 ppm/°C and thin laminate dimensional stability of <0.03%, are explained.
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Gives a bibliographical review of the finite element meshing and remeshing from the theoretical as well as practical points of view. Topics such as adaptive techniques for meshing…
Abstract
Gives a bibliographical review of the finite element meshing and remeshing from the theoretical as well as practical points of view. Topics such as adaptive techniques for meshing and remeshing, parallel processing in the finite element modelling, etc. are also included. The bibliography at the end of this paper contains 1,727 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1990 and 2001.
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