20505 research outputs found
Sort by
Aerodynamic design optimization of large-scale offshore wind turbine blade using CFD
Get PDFRenewable energy is expected to be the main source of power by 2050, bringing an
end to the use of fossil fuels; this is the only way to achieve Net Zero. Wind turbines
which majorly contribute to this agenda, not only help to reduce CO₂ emission, they
are also environmentally friendly and form a cost-effective solution. The aerodynamic
study and design of a wind turbine blade is essential as it is directly linked to the
performance of the wind turbine. The maximum power generating wind turbine
currently operating is the Haliade-X (GE) turbine, which has set a trademark at
producing 14 MW, 13 MW or 12 MW. However, a need for higher power generating
wind turbines is present to be able to reach the Net Zero target.
By upscaling the “DTU 10 MW Reference Wind Turbine” this research has achieved
an aerodynamically stable 20 MW offshore wind turbine blade design. Variable
rotation speed and variable pitch angle configurations have been considered to
achieve an ideal power curve. The aerodynamic performance has been evaluated
using CFD and quantified for a length optimized blade design. To ensure structural
stability, chord and twist optimizations have also been performed.
The chord and twist of the designed blade have been optimized through the
momentum theory and the blade element theory. 2D numerical simulations on FFA-
W3 aerofoils used in the design of the wind turbine blade have been carried out initially
to determine the angle of attack at minimum C/C ratios, which further helps to
calculate the chord and twist of the blade. From the calculated value, a new design
variant has been proposed and the aerodynamic performance has been evaluated
using CFD.PhD in Energy and Powe
Total pressure distortion reconstruction methods from velocimetry data within an aero-engine intake at crosswind
Get PDFThe integration of Very High Bypass Ratio (VHBR) turbofan engines with short intakes may present challenges due to increased total pressure distortion, particularly under crosswind conditions. Current industrial practices rely on a limited number of intrusive pressure sensors arranged on rakes at the Aerodynamic Interface Plane (AIP), to characterise this total pressure distortion. However, non-intrusive measurement techniques provide a more effective way to capture the complex, unsteady flow fields within the intake, offering higher spatial resolution compared to conventional methods. In this study, velocity data obtained from Stereoscopic Particle Image Velocimetry (S-PIV) during wind tunnel tests of a short intake configuration were employed to reconstruct the instantaneous total pressure fields at the AIP within the intake. Two reconstruction methods were used: Direct Spatial Integration (DSI) of the momentum equation and the Poisson Pressure Equation (PPE). These methods were first applied to numerical data from RANS simulations. The results of the reconstruction of the total pressure field based on the S-PIV data were compared against rake measurements. The methods enabled a more comprehensive assessment of total pressure distortion, offering improvements over conventional sensor-based ap-proaches in identifying and characterising total pressure non-uniformities within an intake.This work was conducted under the NIFTI project which received funding from the Clean Sky 2 Joint Undertaking (JU) under Grant Agreement No 86491116th European Turbomachinery Conference (ETC16
Crossbow impact effect on clothing and potential associated injuries
Get PDFThere has been an increase in crossbow use for hunting practices, sport target shooting, and criminal activity. In the UK, there is minimal legislation surrounding the crossbow. UK law states individuals must be over 18 to buy or possess a crossbow. To date, little experimental research has been conducted, with most of the research focusing on injuries resulting from crossbow incidents. The aim of this study was to ascertain what effect crossbow bolts would have against ordinary clothing worn by the public and how or if different combinations of clothing would fare differently against the bolts and if that could be of use to the forensic examiner. An 80 lb. Armex tomcat II crossbow was used with three types of clothing used in four combinations, along with a non‐clothed gelatine block. The results showed that all 10 bolts penetrated the non‐clothed gelatine block, T‐shirt, and polo shirt series, while nine bolts penetrated the hoodie/T‐shirt combination and only three penetrated the hoodie/polo shirt combination. Significant differences were highlighted between the mean penetration depths of the non‐clothed gelatine block and each clothing series, with the highest observed value being the thickest layer combination. Inspections of bolts and wound tracts revealed the presence of clothing fibers. The conclusions of this study demonstrated that this information can be utilized by forensic investigators and medical professionals as a source of trace evidence. Further research into crossbow effects on clothing would prove beneficial to increase the understanding of how the crossbow reacts with the environment.Journal of Forensic Science
Rapid decarbonization requires industrial efficiency
Get PDFThe potential of effciency to support decarbonization is underestimated and overlooked relative to more expensive and intensive actions. Implementing resource and energy effciency strategies in industry could deliver rapid and cost-effective decarbonization.Nature Reviews Clean Technolog
School of aerospace, transport and manufacturing safety and accident investigation
No full textMayer, Robert - Associate SupervisorThe airline pilot’s profession is a highly challenging and ever-changing environment
requiring constant safety-related decisions made by the pilots themselves to ensure
the high standards of the aviation safety system. In an otherwise highly regulated
European aviation safety system, the effects of “pilot commuting” remain a potential
blind spot, even though commuting and its consequences are representing a risk for
the safety of the European air transport system.
This research explores commuting stress, pilot performance, locus of control, turnover
intention and safety behaviour in connection to the European pilot commuting process.
Variables involved in the commuting process are established and analysed. A Europe-
wide airline pilot study sent out to over 15,000 European airline pilots resulted in 1,461
usable questionnaires to examine European airline pilot commuting data for the first-
time. Statistical analysis reveals that commuting is a standard behaviour of many
European pilots. More than half of the European airline pilots declared themselves as
active commuters by the definition of this research. The statistical analyses are based
on structural equation modelling and partial least square (PLS)-structural equation
modelling (SEM). These analyses reveal the interaction of commuting stress, turnover
intention, locus of control, safety behaviour and resulting professional pilot
performance. A predictive model has been developed which explains mediating and
moderating effects on respective variables. The findings shed new light on the
professional pilot performance of commuter, non-commuter and intermediate housing
commuter pilots in Europe. Which were in contrast with what was anticipated from the
research literature. This research identified a significant predictability and interaction
between commuting stress, safety behaviour, and turnover intention. It also highlights
that locus of control has a predictive quality regarding commuting stress. Applying the
theoretical framework of Sloan and Cooper (1986) on pilot performance and the
maximum adaptation model (Hancock and Warm, 2003), a new European airline pilot
commuting model using PLS-SEM predictive qualities was developed.
This research allows a deep insight into commuting risks in terms of optimal pilot
commuting distances and times and resulting pilot performance. It offers an important
and, until now, neglected contribution to the European aviation safety system. A
comparative three-group analysis observed that non-commuters exhibited the lowest
stress levels, while commuters experienced moderate stress due to commuting. Pilots
who used intermediate housing facilities reported the highest stress levels among the
three groups. Moreover, the analysis revealed that European airline pilots engaged in
commuting exhibited significantly better subjective performance when compared to
their non-commuting counterparts. Furthermore, the results indicate that commuters
who utilize intermediate housing exhibit a significantly increased tendency to deviate
from standard procedures on an individual basis, likely due to their unique commuting
needs.
This model presents a foundation for innovating and implementing new strategies in
managing European airline pilot commuting, duty scheduling, and base assignments,
suggesting a positive direction for change based on these research findings.PhD in Transport System
Improving food supply chain resilience: a case study of chicken tikka masala
No full textA Non-Disclosure Agreement is in place between Cranfield University and Company B that includes all sensitive and commercial data gathered. Due to the nature of the research, all data is considered sensitive in that sharing it might feasibly compromise not only the privacy of research participants but also the commercial interests of their organisations in relation to Company B. Therefore, supporting data is not available. The following are available at https://doi.org/10.57996/cran.ceres-2770: Interview instrument; Survey instrument; Plausible future scenarios (narratives); Codebook for thematic analysis.Food supply chain resilience can improve food security in the face of environmental disruptions such as climate change, extreme weather, and disease outbreaks. However, there are many definitions of resilience, and there is still a need to understand its components, barriers and enablers, in order to clarify how businesses and governmental regulators can maintain and enhance resilience. This study seeks to understand how resilience is perceived and operationalised by food chain actors. Resilience strategies in a specific supply chain are investigated, focusing on chicken tikka masala manufactured by a small and medium enterprise (SME). A theoretical framework, based on robustness, recovery, and reorientation, is presented and applied to analyse resilience strategies. The research employs an embedded case study approach comprising surveys, interviews, and a workshop with supply chain actors across three tiers. Thematic analysis reveals that actors prioritise robustness and recovery strategies. However, reorientation strategies, such as long-term adaptability and early warning systems, receive less focus due to perceived investment and capacity constraints, while visibility and collaboration are curtailed in SMEs with limited influence with larger actors. The study highlights key barriers such as fragmented information flows, limited government policy alignment, and challenges of digital technology adoption. Recommendations include the need for policy consultation frameworks that improve policymakers’ understanding of food supply chains and actors’ decision-making processes, and for a strategic vision for the food system that fosters resilience to long-term environmental change.Quadram Institute Bioscience; 43266FSRN-2023S26. Natural Environment Research Council; 2754639Environmental Research: Food System
Understanding the risk of enhanced particle penetration into slow sand filter beds when using underwater skimming techniques
Get PDFThis study evaluated abiotic slow sand filters (SSFs) to understand the risk of particle penetration during underwater skimming (UWS), focusing on clogging, headloss development, and particle breakthrough. Pilot-scale filters containing clean sand were challenged with dispersed kaolin particles to simulate surface accumulation, and the sand surface was agitated to mimic UWS procedures. The study was undertaken with no maturation period to consider the worst-case scenario corresponding to the period just after filter skimming. Agitating the surface and restarting flow released captured particles, some moving downward through the filter. Shallow filter depths resulted in particles appearing in the filtrate, but increasing the media depth beyond 500 mm minimized this effect. Since 90 % of headloss occurred in the upper layers, deeper particle penetration was insignificant. Increasing the hydraulic loading rate from 0.3 to 0.5 m/h reduced particle retention by 0.72 log, yet all abiotic SSFs achieved over 2 log particle capture. Small particles (2–10 μm) were removed by 2 logs, indicating sufficient non-viral pathogen retention under routine conditions. Effective capture of particles sized 2–125 μm suggested minimal risk to water quality and public health during UWS on full-scale SSFs. Using clean sand and kaolin represented a worst-case scenario, excluding biological maturation and particles. The findings suggest that under normal conditions, UWS does not increase deep particle penetration or breakthrough, supporting its safe implementation to enhance filter maintenance without compromising water quality.Engineering and Physical Sciences Research Council (EPSRC)The authors acknowledge the financial support of the Engineering and Physical Sciences Research Council (ESPRC), through the STREAM Industrial Doctorate Centre (EP/L015412/1), and financial support from Thames Water and Northumbrian Water Group.Journal of Environmental Managemen
Technoeconomics of sugar cane bagasse valorization to lactic acid using pinch technology: distillation vs reactive distillation
Get PDFSugar cane is one of the largest agricultural crops, and sugar cane bagasse (SCB), a major waste from sugar cane processing, is an abundant and inexpensive source of fermentable sugars for producing diverse platform chemicals. The present study evaluates the technoeconomic viability of L (+) lactic acid (LA) production from SCB with different stand-alone process scenarios modeled using the pinch method. It critically evaluates various cost-contributing factors when a sugar-rich hydrolysate is obtained via two different pretreatment methods: dilute acid and alkali. The cost-benefit of LA purification by conventional distillation (CD) is further compared to reactive distillation (RD). The pinch method cuts the LA manufacturing costs by 10-11%. Alkali pretreatment combined with RD involves a lower capital investment and utility consumption than the CD counterpart and slightly less LA manufacturing cost. However, LA production via dilute acid pretreatment and purification by RD emerges as the most profitable scenario due to capital investment, utility demand, and chemical consumption savings. This scenario offers the minimum LA selling price of 2.3 US/kg factory-gate LA selling price, the internal rate of return was 31% and the payback period was 4.4 years for an 8.5% discount factor.ACS Sustainable Chemistry & Engineerin
Optimization of dual-module floating photovoltaic arrays: layout configuration and damping mechanisms for enhanced stability and energy performance
Get PDFFloating Photovoltaic (FPV) systems are a promising solution for offshore renewable energy, with modular FPV arrays offering significant potential for large-scale deployment. However, the development of FPV systems is hindered by insufficient understanding of their hydrodynamic performance, which affects stability and energy efficiency. This study proposes a dual-module FPV array combining box-type and semi-submersible modules to improve hydrodynamic stability under mild wave conditions in the South China Sea. The effects of array layout and PTO damping are examined under various wave conditions. The system is optimized to balance energy harvesting and motion control, and its performance is further evaluated under irregular waves at selected operational sites. Results indicate that the dual-module design effectively leverages the hydrodynamic characteristics of both module types, reducing motion responses and dynamic loads. The incorporation of optimal PTO damping further enhances system stability and energy efficiency by effectively suppressing pitch and heave motions, with maximum reductions of 31.43 % and 41.56 %, respectively, under the selected operational wave conditions. While damping remains effective under head-on waves, its performance slightly decreases under oblique waves, underscoring the importance of aligning the array with the predominant wave direction. Additionally, integrating a wave energy PTO system into the FPV array enables wave power to supplement solar energy, contributing 17.04 % of the total energy output at the selected operational sites. The proposed FPV system offers a practical solution for stabilizing floater motion, enhancing solar power generation, and capturing wave energy, advancing the feasibility of FPV technology for large-scale offshore applications.National Natural Science Foundation of China (52222109, 52201322), Guangdong Basic and Applied Basic Research Foundation (2022B1515020036 and 2023A1515012144), Project of State Key Laboratory of Subtropical Building and Urban Science (2023ZB14).Energ
Exploring the social sustainability implications of autonomous vehicle adoption in supply chains
Get PDFYate, Nicky - Associate SupervisorAdopting autonomous vehicles (AVs) in supply chains has shown significant
potential for economic and environmental benefits, however, they are still not
widely deployed in supply chains. In order to gain social approval for wider AV
adoption in supply chains, it is crucial to understand the social implications.
Currently, there is a lack of comprehensive discussion about the social impacts
of AV adoption, and how to improve the social sustainability performance in this
scenario. Therefore, this thesis aims to explore the social impacts and social
sustainability aspects of deploying AVs in supply chains, and the actions
organisations enact to improve social sustainability performance and hence
achieve wider social approval for adopting AVs in supply chains. Using the paper-
based structure, this thesis comprises three interconnected papers which
collectively fulfil this overall research aim: the first paper systematically reviews
the literature in this research domain, and papers two and three present empirical
studies that discuss supply chain social sustainability (SCSS) implications and
the actions needed to improve the SCSS performance of AV adoption in supply
chains.
Paper one titled “Exploring the Social Impacts of Autonomous Vehicle adoption
in Supply Chains: a systematic literature review” aims to identify the positive and
negative social impacts of AV adoption in supply chains as well as the actions
taken by organisations that address the impacts enabling wider AV adoption in
supply chains based on a systematic literature review (SLR). Through reviewing
58 identified papers, this paper identified 13 positive and 7 negative social
impacts of AV adoption in the supply chain. Based on these impacts, a conceptual
model categorising the social impacts under six context-specific SCSS indicators
that are derived from seminal social sustainability literature is formed to measure
the social sustainability performance of AV adoption in supply chains in aspects
including Health and safety, customer satisfaction, employment, transparency,
diversity and equality, and welfare. Stakeholder as an essential element in
analysing SCSS received limited focus in this context, which serves as a research
gap for the second paper to fill. In addition, this paper identifies 20 suggested
actions for organisations to enact for wider AV adoption. These actions are
synthesised into four groups including pilot experiments, regulation improvement,
chain-wide considerations, and education, promotion, and training. However,
wider AV adoption requires wide social approval, which requires the social
impacts to be addressed for improved SCSS performance. The actions are
mentioned to facilitate wider AV adoption, but the existing literature does not
clarify how to address the social implications of achieving wider AV adoption in
supply chains. This means that the actions taken by organisations to address
social implications are currently missing. Therefore, the actions organisations
employ to address social impacts for wider AV adoption serve as the research
gap for the third paper to fill.
Paper two titled “Investigating the Social Sustainability of Autonomous Vehicle
Adoption in Supply Chains: A Delphi Study” refines the social implications
identified from the literature, and discusses stakeholder roles in the AV adoption
context. Based on a three-round Delphi study with 39 experts, 19 positive and 15
negative social impacts are identified and their importance is ranked. In addition
to the existing six identified indicators, “Reputation” is recognised, extending the
concept of SCSS to the AV adoption context. This study also identifies 9 internal
and 17 external stakeholders and evaluates the degree to which they affect or
are affected by AV adoption in supply chains. This finding fulfils the first research
gap of this thesis.
Paper three titled “Improving Supply Chain Social Sustainability in the
Autonomous Vehicle adoption context: A Delphi study with expert interviews”
empirically investigates the actions that organisations take to address the social
impacts of AV adoption in supply chains. The three-round Delphi study suggests
eight categories of actions, which are further validated through 14 follow-up
interviews to evaluate the key SCSS indicators these actions address. Identifying
these actions fills the second research gap of this thesis. To understand how the
organisations at various stages of AV adoption act to improve SCSS
performance, this paper adopts the Diffusion of Innovations (DOI) theory to align
the action categories with the organisational innovation process. This theory
structures the actions on the basis of the AV adoption stages of the organisations
in a logical sequence. The eight categories of actions provide organisations at
various innovation adoption levels with an action plan to address the social
impacts of AV adoption to improve their SCSS performance.
This thesis contributes to knowledge regarding SCSS concepts through an in-
depth investigation of context-specific SCSS indicators and actions for
organisations to enact to improve SCSS performance. It defines the SCSS of AV
adoption in supply chains with a conceptual framework, highlights the degree of
influence of internal and external stakeholders in this context, and defines and
evaluates the actions that address the social impacts for improved SCSS
performance in the AV adoption context. This thesis provides a novel use of the
DOI theory by tailoring the Innovation Process (IP) model with the identified action
categories that apply to the AV adoption context, a continuous improvement
cycle, and the inclusion of the internal/external stakeholders that enact the
actions to improve SCSS.
This thesis contributes to practice by offering an overview of social issues and a
structured action plan to address these issues to improve SCSS performance
when adopting AVs in supply chains. First, the identified social impacts and
stakeholders support organisations in the development of social indices for the
performance measurement of their operations when adopting AVs. Then, the
action plan guides organisations to develop tailored business models to improve
SCSS performance when adopting AVs. Regulators can use the action plan as a
trail of evidence to check whether the organisations achieve SCSS performance
improvement in the AV adoption context by actually implementing the actions or
not.PhD in Leadership and Managemen