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Multidisciplinary preliminary design and integration of the transmission system in a pusher geared contra-rotating open rotor
Get PDFSethi, Vishal - Associate SupervisorOne of the main challenges for the aviation industry is to reduce its global
environmental footprint. Geared contra-rotating open rotors have the potential to
further reduce fuel consumption relative to geared turbofans, but require a more-
complex speed-reducing transmission system to drive the propellers. Hitherto,
the preliminary design for such transmission systems has been reported
independently of the overall engine modelling or has been limited by many pre-
determined engine constraints. This has restricted the feasible design space of
the engine and the transmission system. Therefore, this research addresses two
key questions: Can the preliminary design of the transmission system be done
from cycle parameters without imposing additional engine-based constraints?
How does the introduction of more rigorous preliminary design processes for the
transmission system affect the design space of the open rotor engine?
The transmission system in the contra-rotating open rotor comprises two main
components: a power gearbox and a pitch change mechanism. These technology
enablers enhance engine performance by decoupling the operation of the
propellers from the free power turbine and adjusting the pitch of the blades
respectively. The best power gearbox option in a contra-rotating open rotor is a
differential planetary gearbox, which enables contra-rotation of the output shafts
and a high power transfer with a reduced size. The space envelope of the power
gearbox varies with the torque ratio between its output shafts, connected to the
propellers. The effect of torque ratio variation on gearbox design has been
analysed in this research for equal propeller rotational speeds and different speed
ratios between the output shafts. This research shows that potential torque ratios
lie between 1.1 and 1.33, with the higher ratios enabling more compact
gearboxes having four or five planet gears. However, for a prescribed propeller
rotational speed, higher torque ratios would reduce the rotational speed of the
low-pressure turbine driving the propellers and potentially reduce its efficiency.
Alternatively, increasing propeller rotational speeds would result in thicker radial
shafts for the pitch change mechanism connected to the propeller blades. The
presence of these shafts radially traversing the engine’s gas path might contribute
to the blockage of the exhaust duct.
To address these issues, a preliminary design framework has been developed
that combines 0D thermodynamic modelling with flow path sizing and weight
estimation and enables assessing the integration effects of the transmission
system on engine performance. The engine’s optimum performance design
space might not be accessible due to mechanical constraints or integration
interactions. Relative to a baseline design, the reduction in fuel burnt can be as
high as 1% with current technology levels and 3% for future designs with entry
into service by 2035. However, the potential performance gains derived from
improvements in turbine design might not be achievable when the transmission
system is integrated. The integration of the transmission system further reduces
potential fuel burn gains to 0.6% relative to a baseline engine design.
A wide range of activities for future work is opened by the methods developed in
this research in both performance and mechanical development of the
components in the transmission system.PhD in Aerospac
Nanomaterials as a new frontier platform: metal-doped and hybrid carbon dots as enzyme mimics for environmental applications
No full textEnvironmental pollution has become an inexorable problem for the planet Earth. The precise detection and degradation of heavy metals, pesticides, industrial-, pharmaceutical- and personal care- products is needed. Nanotechnology holds great promise in addressing global issues. Over the past decades, nanozymic nanomaterials have exceptionally overcome the intrinsic limitations of natural enzymes. Carbon dots (CDs) exhibit unique structures, surface properties, high catalytic activities, and low toxicity. Different techniques, such as doping or surface passivation, can enhance these exceptional properties. Doping modifies CDs’ electronic, magnetic, optical, and catalytic properties considerably. Metal doping, a more significant strategy, involves the introduction of metallic impurities, which offer insight into enhancing the physicochemical properties of CDs. Metal-doped CDs exhibit higher optical absorbance and catalytic performance than pristine CDs. The literature shows that researchers have utilized various synthetic approaches to fabricate CDs-Metal nanozymes. Researchers have reported the metal-doped and hybrid CDs’ peroxidase, catalase, laccase, and superoxide dismutase-like activities. These metal-doped nanozymes put forward substantial environmental remediations and applications such as sensing, photocatalytic degradation, adsorption, and removal of environmental contaminants. This review thoroughly discussed the metal-based functionalization of CDs, the enzyme-like properties, and the ecological applications of metal-doped and hybrid enzymes. The review also presents the current novelties, remaining challenges, and future directions with key examples.Frontiers in Material
Solidago canadensis modifies microbial community and soil physicochemical properties through litter leachates and root exudates
Get PDFInvasive plant inputs alter soil microbial communities via chemical compounds in litter, root exudates, and leachate, impacting a range of soil processes, but precise effects are poorly understood. We examined Solidago canadensis, a common invasive species in China, and its litter effects on soil microbial communities under natural conditions. Experimental treatments included S. canadensis seedling density (1 and 2 plants/pot) and quantity of litter (10 and 20 g/pot), with control groups that contained no plants or litter. After 120 days, soil samples were analyzed for physico-chemical properties, GC-MS chemical composition, and bacterial community composition using high-throughput sequencing. Results showed that S. canadensis seedlings and litter inputs increased soil pH, organic matter (SOM), and nitrogen (TN), while phosphorus and potassium remained unchanged. We identified 66 chemical compounds, predominantly ketones, alcohol, aldehyde, hydrocarbon, ester, acid, terpenoids, and alkaloids, associated with the presence of the invasive species, alongside shifts in dominant bacterial genera including Sphingomonas, Acidobacteriales, and Gemmatimonas. Rarer genera under the invasive treatment species, such as Candidatus, Rhodoplanes and Novosphingobium, correlated positively with soil TN, pH, and SOM. Collectively, our results demonstrate how the increased presence of allelochemicals from S. canadensis litter significantly impact soil properties and bacterial communities, and may therefore have implications for ecosystem dynamics.This work was supported by the National Natural Science Foundation of China (31971427), Carbon Peak and Carbon Neutrality Technology Innovation Foundation of Jiangsu Province (BK20220030), and the Young Scientist Fund of Jiangsu Province (BK20200905). Part of the funding for this research was supported by the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment and the Special Scientific Research Project of the School of Emergency Management, Jiangsu University. The authors would also like to thank the Researchers Supporting Project Number (RSPD2025R668), King Saud University, Riyadh, Saudi Arabia.Journal of Plant Ecolog
Deep learning for urban wind prediction: an MLP-Mixer approach with 3D encoding
No full textPedestrian-level wind environments are strongly influenced by urban morphology, with large and tall buildings playing a significant role. City authorities increasingly mandate assessments of pedestrian wind conditions before approving new construction. Computational fluid dynamics (CFD) models can provide a detailed understanding of the aerodynamic environment; however, in early design stages, urban morphologies are subject to change, requiring multiple simulations, adding substantial financial and time burdens to projects. To address this challenge, we develop a deep learning approach for the rapid inference of pedestrian-level wind conditions using a multi-layer perceptron (MLP)-mixer architecture. By embedding 3D structural details into the training data, our model can infer wind conditions around complex structures such as lift-up designs and skyways while maintaining inference times on the order of fractions of a second. This extends the capabilities of deep learning models that typically reduce the problem to a 2D image-to-image translation task, omitting crucial structural details. We conduct an extensive evaluation of our model and compare its performance to the widely adopted UNet architecture, demonstrating that the MLP-mixer outperforms UNet across all evaluation metrics. Notably, the MLP-Mixer achieves a mean squared error approximately 2.6 times lower, a peak signal-to-noise ratio 3.7 dB higher and the highest recorded structural similarity index of 0.991. These results indicate improved agreement with the reference CFD data. We anticipate that the MLP-mixer model will serve as a valuable tool in early-stage urban design workflows, enabling faster and more efficient wind assessments.Cranfield UniversityNablaflow ASBuilding and Environmen
A feasibility study on space-based solar power for lunar economy
Get PDFEnergy solutions are essential for the exploration and establishment of long-term lunar activities. Re-energized rush for lunar adventures in the near term and future, alongside investigation of lunar bases in the upcoming years. Most of the current mission functions for a relatively short lifetime of research activities, and they include continual testing with landers to test the survivability of stringent temperatures on the lunar with varying levels of autonomy, resulting in new insights, and requirements for future settlements over the Moon ultimately paving step towards Mars colonization. Current suggested or planned power sources have Batteries, Fission Surface Power, and Vertical Solar Array Technology (VSAT) may encounter hurdles in terms of efficacy, scalability, significant system failures over time due to harsh space weather and lunar environment, and specially during the long prolonged lunar nights. To overcome the obstacles posed in the lunar environment, an innovative technique called Space-Based Solar Power (SBSP) is a prospective option to support lunar explorations, and infrastructure. A systems engineering breakdown approach is employed to explore the feasibility study of the proposed technology. That led to the breakdown of each step as a requirement to address the needs. The whole architecture is partitioned into data set formation of current, future, and past missions, where this information leads to developing hypothesis and approximation for the lunar operational needs, and lunar power demand analysis is driven by utilizing the data set. The above steps are defined to evolve a qualitative study for formulating different concepts and a thorough trade-off analysis addressed to select a concept. The above steps lead to the development of mathematical frameworks to fulfill the expected power demand. The study indicates that SBSP systems are a realistic and scalable alternative for satisfying the lunar economy’s energy demands, overcoming hurdles such as long lunar nights and harsh climatic conditions. Simulations and trade-off evaluations show that SBSP systems based on Microwave electricity Transmission (MPT) can offer continuous and dependable electricity. Economic budget estimates provide vital insights into the overall profitability and sustainability of the determined architectural concept. The findings show SBSP systems’ flexibility in dealing with lunar circumstances, integration possibilities with future infrastructure, and long-term cost advantages over alternative energy methods. While hurdles remain notably in lunar dust mitigation, SBSP promises a game-changing method to power long-term lunar operations, facilitating industrial growth and supporting human and robotic activities. Keywords: Space-Based Solar Power (SBSP); Microwave Power Transmission; Laser Power Transmission; Solar Reflectors; Lunar Surface Technology Research (LuSTR); Lunar Infrastructure; Lunar Exploration.AIAA Aviation Forum and Ascend 202
Tracing time through cuticular clues: the role of rearing conditions and generational divergence in Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae)
No full textThe chemical profiles of the cuticle of adult flies are highly influenced by environmental factors and generational variation, although the extent and mechanisms of these influences are still poorly understood. This research rigorously investigates the influence of rearing environment and generational changes on the cuticular hydrocarbon (CHC) profiles of adult flies collected from the natural environment in Swindon (UK), in June 2019. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the hydrocarbon profiles. Then, chemometric analysis was applied to determine the chemical variation patterns, allowing the samples to be classified according to their chemical fingerprints. Significant differences in hydrocarbon composition were found between laboratory-maintained and field-collected specimens, underscoring the impact of environmental conditions on CHC expression. Additionally, gradual modifications in hydrocarbon content were detected across generations raised in the controlled environment, suggesting the involvement of adaptive physiological or epigenetic mechanisms. These findings contribute valuable insights into cuticle plasticity, highlighting its relevance in forensic entomology, chemical ecology, and insect evolutionary biology. The implications also extend to forensic investigations, where cuticular hydrocarbon profiles (CHCs) demonstrate potential for enhancing postmortem interval (PMI) estimation accuracy and species identification in criminal cases. By demonstrating quantifiable differences in CHC composition across rearing conditions and generations (AUC values ≥0.92 for all comparisons), this study provides a foundation for the broader application of chemical markers in forensic investigations.First author (Dr. Canan Kula) received sponsorship from the Ministry of National Education of the Republic of Türkiye.Turkish Journal of Entomolog
F93B - CAD model, performance evaluation, role conversion and cost prediction.
No full textEuropean air forces have a general requirement for a new, multi-purpose large aircraft. Whilst the major need is for a replacement for the Lockheed C-130 Hercules, it is envisaged that the aircraft should be capable of fulfilling other roles. These include anti-submarine maritime patrol and tanker missions.
This thesis discusses the construction of a Computer Aided Design (CAD) model of the F93B and outlines the process required to convert the CAD model into a physical model. It also evaluates in detail the overall performance and costs of the F93B turbo-prop aircraft and basic pressure loading for the wing an fuselage using the SPARV aerodynamic panel program. Additionally, the conversion of the aircraft into an anti-submarine maritime patrol aircraft was assessed.
The F93B proved to be a very capable aircraft with a maximum take-off distance requirement of 1375m which was well within the design specification of 1500m. The rate of climb and service ceiling were a considerable improvement on the C-130 and the 3-engine performance of the F93B was exceptional. The F93B has a ferry range of 10186km compared with 8750km for the C-130 and the payload/range requirement was exceeded by 475km (8.6%).
The role conversion to a Maritime Patrol Aircraft (MPA) involved the addition of a large quantity of equipment both internally and externally including tactical operators positions, surveillance equipment, sonobuoys, radar, Electronic Support Measures (ESM) as well as offensive and defensive weapons for anti-submarine warfare. The maximum endurance of the F93BMPA with an internal fuel tank fitted is 14.6 hours which meets the specification laid down by the RAF for its maritime patrol aircraft of the future. However, the lack of a bomb bay means that the F93B has a limited offensive capability.
The unit cost of the basic F93B transport aircraft is US 63 million. The operating costs per flight hour are US 5765 respectively.MSc in Aerospace Vehicle Desig
Optimising hydrogen carrier pathways for industrial decarbonisation: a techno-policy framework for readiness in infrastructure and governance
No full textIndustrial decarbonisation is a major route to net-zero emissions, and hydrogen is emerging as a key energy carrier for hard-to-abate sectors. This work applies a techno-policy readiness framework which encompasses infrastructure compatibility, regulatory institutional alignment, technological readiness, and market readiness, to improve hydrogen carrier pathways for industrial purposes. The framework uses comparative assessments of production routes, transport and storage pathways, and policy instruments to assess the techno-economic performance and governance readiness to support each hydrogen carrier pathway. The findings indicate that ammonia and liquid organic hydrogen carriers (LOHCs) have the highest readiness for long distance transportation, while compressed hydrogen and liquid hydrogen can still be used for shorter distances or niche markets. The analysis also indicated that successful hydrogen rollout will depend as much upon governance and infrastructure alignment, and not only on technical readiness. Overall, this research provides realistic pathways for policymakers and industry actors to expedite their hydrogen uptake into industrial systems, and ultimately enable a quicker transition to global decarbonisation goals.International Journal of Hydrogen Energ
Tracing the botanical origins of UK heather honey by relative quantification of plant DNA
No full textHeather honey is an important honey type produced in the UK, valued for its unique flavour, thixotropic texture and health-promoting properties. Botanical authentication can be challenging due to the natural variability in honey composition and typical pollen analysis relies heavily on expert knowledge. As an alternative, real-time PCR (qPCR) can be a rapid and robust method to identify floral species in honey. In this work, species-specific markers for Calluna vulgaris and Erica cinerea were developed and used to quantify 266 honey samples relative to the plant trnL P6 loop. The method classed 96% of 234 heather honeys as containing > 3% heather DNA, with 68% classified as dominant (> 45%) for ling heather origin. Moreover, high specificity was achieved with negligible amplification in the 32 non-heather honeys. Our qPCR method offered comparable results to melissopalynology, DNA metabarcoding, and digital PCR, showing potential as an alternative and accessible method for botanical authentication of heather honeys.This research was funded by UKRI BBSRC FoodBioSystems Doctoral Training Partnership (DTP), grant number BB/T008776/1.npj Science of Foo
Waterborne pathogen mitigation: decoding techno-ecological synergies in multiscale transmission networks
No full textPathogen spread and infection represent paramount global challenges, their intricate transmission pathways fundamentally shaped by human behavior and anthropogenic influences. Here, we elucidate pathogen transmission networks in the environment and identify the increasing risks resulting from mutant viruses and resistant bacteria. We examine the advantages and limitations of techniques for pathogen detection and advocate the development of real-time, high-precision, point-of-need assays capable of detecting microorganisms in waterborne matrices, providing a new conceptual and technological approach to future detection methods. We also highlight the inadequate protection of existing centralized disinfection methods and propose the implementation of decentralized disinfection (i.e., chemical-free and energy-efficient point-of-use disinfection) as a form of multi-barrier protection throughout the different pathways of pathogen transmission. A robust and resilient ecosystem can prevent containment sources and inhibit the bioactivity of residual pathogens, and when working in synergy with multi-barrier disinfection, can achieve a techno-ecological framework for pathogen mitigation. We further address the fact that data-driven technologies (e.g., artificial neural networks and machine learning methods) provide a route for intelligent detection-guided disinfection and the accurate selection of pathogen indicators that are directly relevant to human health. Finally, we highlight concerns regarding potential high-risk pathogens due to climate change.This work was supported by the National Key R&D Program of China (grants 2022YFC3205400 and 2022YFC3204703), the National Natural Science Foundation of China (grant 52200079), and the UKRI Horizon Europe Guarantee funding of Marie Skłodowska-Curie Actions Postdoctoral Fellowship (grant EP/X022730/1).The Innovatio