Reports on the MSc group design project of students at the College of Aeronautics, aerospace vehicle design in 1995. The students worked on advanced short take‐off and vertical…
Abstract
Reports on the MSc group design project of students at the College of Aeronautics, aerospace vehicle design in 1995. The students worked on advanced short take‐off and vertical landing of a combat aircraft. Details the project showing aircraft dimensions and design. Full assessment of the results is pending, but outlines a number of problems faced by the students.
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Eduardo Sepulveda Palacios and Howard Smith
The purpose of this paper is to characterise the effects of mission and performance parameters on the design space of low observable subsonic unmanned combat aerial vehicles…
Abstract
Purpose
The purpose of this paper is to characterise the effects of mission and performance parameters on the design space of low observable subsonic unmanned combat aerial vehicles (UCAVs) operating in typical Hi-Lo-Hi ground strike missions.
Design/methodology/approach
Conceptual design methodologies appropriate to low observable, tailless UCAVs have been integrated into a multidisciplinary aircraft design environment, GENUS, developed at Cranfield University’s aircraft design group. A basic Hi-Lo-Hi mission is designed and a baseline configuration is established through the GENUS framework. Subsequently, an evolutionary optimiser and a robust gradient-based optimiser are used to obtain convergent design solutions for various leading edge sweep angles, mission ranges, cruise Mach numbers and other operational constraints.
Findings
The results indicate that performance constraints, specifically in the form of specific excess power (SEP), have a large influence on the overall sizing of subsonic tailless UCAVs. This requirement drives the engine sizing, which represents a considerable proportion of the empty and gross mass of the vehicle. Cruise Mach number studies show that no significant advantages exist for operating at low speeds while maintaining performance requirements consistent with combat missions. There is a drastic increase in the vehicle’s mass and thrust requirements for flight speeds above Mach 0.8, with low sweep configurations showing a more pronounced effect. Increases in the range are not overly dependent on the leading edge sweep angle. Top-level radar cross section (RCS) results also favour configurations with higher leading edge sweep angles, especially from the nose-on aspect. Finally, research and development costs are shown to be directly linked to engine size.
Originality/value
This research shows the use of an integrated aircraft design environment that incorporates aerodynamics, performance, packaging and low observability aspects into the optimisation loop. Through this methodology, this study supports the efforts towards characterising and establishing alternate visions of the future of aerial warfare through the use of low cost, survivable unmanned platforms in network-centric cooperative tasks.
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Chenhao Wei, Gang Lin, Jun Huang, Lei Song and Howard Smith
Unlike conventional aircraft, birds can glide without a vertical tail. The purpose of this paper is to analyse the influence of dihedral angle spanwise distribution on…
Abstract
Purpose
Unlike conventional aircraft, birds can glide without a vertical tail. The purpose of this paper is to analyse the influence of dihedral angle spanwise distribution on lateral-directional dynamic stability by the simulation, calculation in the development of the bird-inspired aircraft and the flight testing.
Design/methodology/approach
The gliding magnificent frigatebird (Fregata magnificens) was selected as the study object. The geometric and mass model of the study object were developed. Stability derivatives and moments of inertia were obtained. The lateral-directional stability was assessed under different spanwise distributions of dihedral angle. A bird-inspired aircraft was developed, and a flight test was carried out to verify the analysed results.
Findings
The results show that spanwise distribution changing of dihedral angle has influence on the lateral-directional mode stability. All of the analysed configurations have convergent Dutch roll mode and rolling mode. The key role of dihedral angle changing is to achieve a convergent spiral mode. Flight test results show that the bird-inspired aircraft has a well-convergent Dutch roll mode.
Practical implications
The theory that birds can achieve its lateral-directional stability by changing its dihedral angle spanwise distribution may explain the stability mechanism of gliding birds.
Originality/value
This paper helps to improve the understanding of bird gliding stability mechanism and provides bio-inspired solutions in aircraft designing.
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Martin Götz and Ernest H. O’Boyle
The overall goal of science is to build a valid and reliable body of knowledge about the functioning of the world and how applying that knowledge can change it. As personnel and…
Abstract
The overall goal of science is to build a valid and reliable body of knowledge about the functioning of the world and how applying that knowledge can change it. As personnel and human resources management researchers, we aim to contribute to the respective bodies of knowledge to provide both employers and employees with a workable foundation to help with those problems they are confronted with. However, what research on research has consistently demonstrated is that the scientific endeavor possesses existential issues including a substantial lack of (a) solid theory, (b) replicability, (c) reproducibility, (d) proper and generalizable samples, (e) sufficient quality control (i.e., peer review), (f) robust and trustworthy statistical results, (g) availability of research, and (h) sufficient practical implications. In this chapter, we first sing a song of sorrow regarding the current state of the social sciences in general and personnel and human resources management specifically. Then, we investigate potential grievances that might have led to it (i.e., questionable research practices, misplaced incentives), only to end with a verse of hope by outlining an avenue for betterment (i.e., open science and policy changes at multiple levels).
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Hanmei Chen and Steven Howard Smith
The purpose of this paper is to examine whether Washington State school district financial reporting and budget reporting meet the information needs of school board directors…
Abstract
Purpose
The purpose of this paper is to examine whether Washington State school district financial reporting and budget reporting meet the information needs of school board directors charged with governance.
Design/methodology/approach
Washington State school board directors were surveyed and asked to rank information items’ usefulness in carrying out their governance role. School district annual reports, budgets and websites were examined to determine whether the identified information was reported and easily transparent to those charged with governance and the public.
Findings
Directors rank information on strategic oversight, budget planning and student outcomes as more useful, consistent with the strategic role of new public management. Follow-on analysis of district annual financial reports, budgets and websites reveal that the availability of the information ranked useful by directors is limited. The findings suggest an information gap exists between directors’ information needs and school district reporting. Annual reports and budgets, when provided, often provide typical financial statements and variance data, respectively, rather than reporting on mission-aligned performance measures. The main consequence of the information gap may be compromised decision-making effectiveness.
Originality/value
By directly asking those charged with governance what information they identify as useful and then examining whether the information is reported in the annual report, budget or website, the study links user information needs to information transparency.
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The systems aspects of an uninhabited tactical aircraft (UTA) preliminary design are detailed. The study, performed at the post‐graduate level at Cranfield University, looks to…
Abstract
The systems aspects of an uninhabited tactical aircraft (UTA) preliminary design are detailed. The study, performed at the post‐graduate level at Cranfield University, looks to investigate the feasibility of unmanned combat aircraft in a number of roles to reduce the risk to pilots and reduce life cycle costs (LCC). The scope of the work includes stealth, vulnerability, mission effectiveness, avionics, landing gear, secondary power, fuel systems, propulsion, performance and cost. The unusual depth to which the design work progressed enables insights to be gained that far exceed those available at the conceptual design phase. A Northrop Grumman concept of near‐identical configuration has subsequently reached the public domain.
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Katharine McMahon, Jamie Pockrandt, Stefanie Fox, Nick Zike and Liu-Qin Yang
Past research has primarily focused on the negative impact of workplace mistreatment or aggression on the individuals involved, workgroups, and organizations. Certain…
Abstract
Past research has primarily focused on the negative impact of workplace mistreatment or aggression on the individuals involved, workgroups, and organizations. Certain circumstances, however, create paradoxical effects in which mistreatment positively relates to desirable workplace outcomes and characteristics at the individual and/or organizational level. Reviewing the theoretical and empirical evidence of beneficial outcomes provides researchers and practitioners with a more comprehensive understanding of the progression of workplace mistreatment, allowing them to target specific mechanisms to mitigate detrimental effects and potentially discover important avenues that lead to desired outcomes. A qualitative review of 13 articles demonstrated that different forms of aggression such as bullying, abusive supervision, incivility, and ostracism have positive relationships with paradoxical outcomes and characteristics such as resilience, prosocial behaviors, socially desirable behaviors, job performance, job satisfaction, and creativity. The authors caution against leveraging mistreatment as a method for producing these desired outcomes; instead, the authors encourage researchers and practitioners to utilize the information to further their understanding of the nomological network of workplace mistreatment and its underlying mechanisms, such as cognitive reappraisal and social learning.
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Successful teams tend to be highly cohesive and team cohesion to be particularly helpful in allowing teams and their members to sustain their success even in the most challenging…
Abstract
Successful teams tend to be highly cohesive and team cohesion to be particularly helpful in allowing teams and their members to sustain their success even in the most challenging times. One disillusioning consequence of this reciprocity between cohesion and performance would suggest that failures made by teams and/or their members likely jeopardize their success by preventing them from capitalizing on such virtuous circles associated with team cohesion. Yet, many teams uphold their performance despite the failures they have to cope with, suggesting that the potential vicious circles can be overcome. This chapter aims at illuminating the vicious and virtuous circles associated with team cohesion that are induced by either collective failures of teams or individual failures of their members. It therefore offers a multilevel perspective not only on the emergence and diffusion of failures at the individual and team levels, but also on the critical role that team cohesion plays for a team’s (dys)functional coping across these levels. It is theorized that collective failures triggered exogenously can help build team cohesion, and that whether endogenously-triggered collective failures bring about the vicious or the virtuous circles of team cohesion depends on whether the individual failures developing into collective failures are triggered endogenously or exogenously. The implications of this conceptual work are discussed in light of the literatures on error/failure management and group cohesiveness.