20505 research outputs found
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Usability assessment on existing alerting designs for emergency communication between passengers and cabin crews
Get PDFSince the deregulation of commercial air travel afterWorldWar II, airlines are forced to differentiate their product in competition with each other. Whereas providing enhanced service during flight is the only way how airlines can fight for passengers. Unfortunately, this need for competition reduces flight attendants main responsibility in public perception as serving refreshments and keeping the cabin tidy. However, the key role of cabin crew is to ensure safety and security. Flight attendants need to handle multiple unexpected situations in a professional manner. A mean for communicating with cabin crew is the Passenger Call Button. The button is not solely used by passengers, but also commonly used by flight attendants in their routine. Research question. This paper explores how the current design is being used by passengers and cabin crew and its limitations during daily operations. Methodology. Two separate questionnaires were distributed to passengers and cabin crew to assess how the PCB is being used and what the limitations of the current design are. Results. The Passenger Call Button is mainly used for service requests. There is an association between travel duration and use of the PCB, as well as there is an association between travel class and the use of the PCB. Passengers as well as cabin crew stated that the existing design is not enabling discreet communication. Discussion. The results highlight the design flaws of the existing alerting design. Passengers as well as cabin crew use the PCB for their own communication practices. Training on how to use the device are missing. The results stress the need for an improved design and training needs. Conclusion. It is necessary to decouple the emergency alerting function from the service function to improve delayed response times. To support cabin crew during emergencies it is important to include an emergency alerting device.German Aerospace Conference 202
Vortex lattice CFD application and modeling validation for ground effect aircraft
Get PDFThis paper explores the application of vortex lattice computational fluid dynamics method capability to model aircraft flight near to ground, utilizing the ground effect. Computational results were correlated with existing analytic formulations and benchmarked against experimental data from the public domain. A case aerodynamics design study was formed, based on the Russian A-90 Orlyonok Ekranoplan wing. The study provided a verification and a validation step towards advancing ground effect aircraft turnaround conceptual and preliminary design time, using the rapid aerodynamics results generation vortex lattice CFD method.WSEAS Transactions on Fluid Mechanic
Evaluation of soft tissue simulant performance against economic and environmental impact
No full textSoft tissue simulants are traditionally used to provide a post impact medium suitable for replicating human anatomy. Performance of materials is therefore paramount, and the analysis of such experimentation relies on responses that mimic the various tissue, bone and muscle groups contained within the human body. However, with an increasing global push to reduce carbon emissions and increase sustainability, current materials require examination to ensure research establishments remain at the forefront of environmentally friendly practices. To date, the literature contains little in relation to how environmentally friendly the use and supply of soft tissue simulants is. The aim of the research is to provide researchers with primary data to support decisions on material selection for ballistic simulation research. The need arises due to the high cost and environmental impact of existing materials. To explore this research gap, a series of 5.5 mm ball bearings were fired from a gas gun at velocity ranges between 122 and 526 m s−1 to examine the performance characteristics of six commercially available soft tissue simulants and a foodstuffs grade gelatine that represented a more cost effective environmentally friendly alternative. A structured multi-criteria decision analysis approach was employed to compare the overall effectiveness of the alternative materials. It was found that whilst PermaGel, 20 and 10% ballistic gelatine performed the most advantageously respectively during experimental testing, qualitative environmental assessment showed ballistic soap, PermaGel and foodstuffs gelatine to be most advantageous. The information provided within this study will enable researchers to make more informed decisions on both economic and environmental implications when sourcing materials for use within survivability assessment, whilst further work would increase awareness and viability of alternative materials.This research was supported by Cranfield Forensics Institute and Defence Equipment and Support.Environmental Sciences: Advance
Motion estimation of an aircraft model using computer vision
Get PDFDynamic wind tunnel tests are used to investigate the flight dynamics of aircraft. Currently contact measurement systems are used which increase friction and require on-board instrumentation. A vision-based method is proposed in this paper. The method uses a sequential process of Harris corner detection, Kanade-Lucas-Tomasi tracking, and Euler angles to identify the Euler angles from a pair of cameras, one with a top-view and the other with a side-view. The method is tested by simulating a 3D CAD model for a single degree of freedom rotational motion. The results have been quantified through numerical analysis and the proposed method is analysed analytically. The developed method is effective when integrated with another method of instrumentation such as an IMU.AIAA SCITECH 2024 Foru
Exploring the contours of consumer heterogeneity: towards a typology of domestic hydrogen acceptance
Get PDFHydrogen energy technologies are anticipated to play a fundamental role in securing a decarbonised energy future. While the deployment of low-carbon hydrogen energy systems remains nascent and is subject to a range of techno-economic constraints, potential scalability will also hinge on social acceptance. In response, this study draws on extensive national survey data to derive a comprehensive typology of domestic acceptance, which reflects multiple factors influencing consumer attitudes towards low-carbon hydrogen heating and cooking appliances. The proposed typology is developed through rigorous coding of over 1000 qualitative statements, leading to 12 core acceptance factors composed of a mix of positive, neutral, and negative sub-factors. The study finds that eight primary sub-factors account for close to 60 % of identified codes, with knowledge deficit (negative), environmental benefits (positive), and financial risks (negative) ranking highest. Critically, these three sub-factors are also the most statistically significant predictors of consumer heterogeneity. At the sub-group level, the analysis shows that engagement with renewable energy technology and climate change is associated with stronger perceptions of environmental benefits and lower financial concerns. By contrast, perceived financial risks and concerns over energy injustice constrain acceptance levels among fuel stressed respondents. Through mixed-methods analysis, the study transmits the value of advancing acceptance typologies as a critical mechanism for enacting a ‘just’ hydrogen economy. The analysis supports developing strategic measures which account for consumer heterogeneity to better support socially acceptable pathways for residential decarbonisation.Energy Research & Social Scienc
Modeling a hydraulically powered flight control actuation system
Get PDFMany different types of aircraft designs have flight control systems (FCS) powered by hydraulic systems. With respect to the torques, moments, surface areas, and opposing forces to be acted upon, components introduce faults into the hydraulic system when these components are aging or degrading. The diagnostics of a hydraulically powered flight control actuation system (HPFCAS) rely on the faults produced within the subsystem components as well as the entire system’s mechanism itself. In this paper, a model for an HPFCAS is developed to analyze faults where the HPFCAS was approached as a system of systems (SOS). The identified faults were injected into the system. It is established that some of the faults from the different subsystems had similar characteristic effects and were propagated with attendant consequences. For instance, a measured decrease in the pressure value is observed because of the decrease in the pump speed. A similar characteristic is observed if there is leakage on the line or if there is a clogging valve. These form complex integrated responses in determining where the fault is coming from if only one component is analyzed since it involves components serving different subsystems. Results show that only models that can describe the real characteristics or attributes of the specific systems, due to their defined components, are sufficient for effective diagnostics. This is because the data obtained are more accurate at predicting the behavior of components.Applied Science
CFD study of shock bump roughness for transonic shock control and buffet alleviation
Get PDFShock induced separation is a serious problem in the transonic flow regime which leads tobuffet - unsteady aerodynamic loading on the wing, that can cause serious structural fatigueand failure. These phenomena compromise the flight envelope and structural integrity ofan aircraft, and consequently its operational safety. One possible solution is to control anddelay the boundary layer separation. The aim of this work was to numerically study whethersub-boundary layer scale distributed roughness, arranged in periodic strips, which locallyincreases the boundary layer displacement thickness, can act as a virtual shock bump withthe aim of bifurcating the foot of the shock wave to reduce the shock’s adverse effect on theboundary layer. A full span bump (upper surface aerofoil shape) model mounted on the floor ofa transonic wind tunnel was previously tested with several configurations of such shock-bumproughness. This study performed steady Navier-Stokes CFD analysis of the working section flowto match the experimental data for the smooth surface bump, and then to assess the affect ofsimulated shock bump roughness. The performance of several turbulence models was comparedwith experimental data (Mach 0.55 inflow, Reynolds number based on bump chord between 3.1 -3.6 million) - the−SST model being found to be the most accurate for this type of problem. Itwas predicted that shock-bump roughness tends to move the shock wave downstream and reduceits strength in cases where the roughness elements are located directly under the interaction,as in the solid shock bump case. This suggests that the virtual displacement effect of surfaceroughness can be designed to provide the same shock-bump effect as a solid protuberance butpotentially without the extra weight and pressure drag. Shock-bump roughness arranged instrips aligned with the streamwise flow were predicted to perform better than those arranged ata 30 degree skew angle to the flow. No conclusive evidence from the numerical models showsthat shock-bump roughness can improve the separated flows if placed upstream of the shock, incases where the shock wave moved downstream of the roughness location.AIAA SCITECH 2024 Foru
Perennial flower margins reduce orchard fruit damage by rosy apple aphid, Dysaphis plantaginea (Homoptera: Aphididae)
Get PDFSown or natural flower strips are a commonly used management practice in agroecosystems and have been demonstrated to increase the abundance of predators of orchard pests. There is less evidence of the extent to which such strips can reduce pest damage in orchards.
Here we examined the effect of managed, perennial flower margins on fruit damage by an economically significant crop pest, Dysaphis plantaginea, rosy apple aphid, in conventional apple orchards over 2 years, compared to orchards without flower margins.
We found orchard flower margins reduced the percentage of apple trees with fruit damage by D. plantaginea, from 80% to 48%. In 2021, a period of severe infestation (65% of trees had fruit damage), there was reduced spread of D. plantaginea on infested apple trees and the number of trees with fruit damage was significantly reduced up to 50 m into orchards. During 2022, a period of lower infestation (25% of trees damaged), fruit damage was significantly reduced up to 10 m from the flower margin.
A significant reduction in predation of aphids from bait cards in flower margin compared with control orchards suggests specialists, rather than generalist predators, may be driving the positive effects of the margin on pest pressure. There was no significant effect of flower margins on abundance of important aphid predators, including Syrphidae (hoverflies) and Coccinellidae (ladybirds).
Synthesis and applications: To our knowledge, this study is the first to detect a reduction in fruit damage by pests at harvest in orchards with a flower margin. We highlight the potential for established perennial flower margins to deliver measurable, sustainable, D. plantaginea control benefits and provide insights into the optimal spatial arrangement of flower strips in orchards.Journal of Applied Ecolog
Driver steering behaviour modelling based on neuromuscular dynamics and multi‑task time‑series transformer
Get PDFDriver steering intention prediction provides an augmented solution to the design of an onboard collaboration mechanism between human driver and intelligent vehicle. In this study, a multi-task sequential learning framework is developed to predict future steering torques and steering postures based on upper limb neuromuscular electromyography signals. The joint representation learning for driving postures and steering intention provides an in-depth understanding and accurate modelling of driving steering behaviours. Regarding different testing scenarios, two driving modes, namely, both-hand and single-right-hand modes, are studied. For each driving mode, three different driving postures are further evaluated. Next, a multi-task time-series transformer network (MTS-Trans) is developed to predict the future steering torques and driving postures based on the multi-variate sequential input and the self-attention mechanism. To evaluate the multi-task learning performance and information-sharing characteristics within the network, four distinct two-branch network architectures are evaluated. Empirical validation is conducted through a driving simulator-based experiment, encompassing 21 participants. The proposed model achieves accurate prediction results on future steering torque prediction as well as driving posture recognition for both two-hand and single-hand driving modes. These findings hold significant promise for the advancement of driver steering assistance systems, fostering mutual comprehension and synergy between human drivers and intelligent vehicles.Automotive Innovatio
Managing the spread of COVID-19 pandemic in Indonesian sea transportation
Get PDFCOVID-19 has been pandemic since the early 2020 and many efforts have been carried out worldwide. Among others, managing the spread of pandemic has been focused on air transportation since the mobility of people has been more actively using aeroplane hence the possibility of infecting people is much higher. Despite less intense, efforts to minimise the blow-out of COVID-19 in sea transportation have also been conducted. The International Maritime Organization (IMO) released guidance such pretravel information to crews and customers The types of guidance include the following items, namely pre-departure, social distancing, the use of masks, personal hygiene, environmental hygiene, and training. In the case of Indonesia, similar direction is introduced and implemented to cargo and passenger vessels. The current paper discusses the Indonesian regulation of managing COVID-19, which is based on IMO/WHO guidance, together with its implementation in the daily activities of people in sea transportation. A survey questionnaire is made out to collect the relevant information. The discussion covers the implementation of such guidance to Indonesian cargo and passenger vessels difficulties in applying the regulation on those ships and the related solutions.This work is part of a project that has received funding from the British Council under the Newton Institutional Links Grants -Ensuring the safety of Indonesian seafarers and fishers in the time of COVID-19 and beyond (agreement No. 623457938), in conjunction with the Indonesian Governmental Funding from the Ministry of Education, Culture, and Higher Education (agreement No. 1369/PKS/ITS/2022)Journal of Marine-Earth Science and Technolog