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Development of liquid-sprays numerical modelling approaches for low-emission gas turbine combustion systems
Get PDFSethi, Vishal - Associate Supervisor
Gauthier, Pierre - Associate SupervisorComputational Fluid Dynamics (CFD) is used to guide the design of novel low-emission
gas turbine combustion technologies. For combustion systems using liquid fuels, injecting
the spray in crossflow, coupled with enhanced turbulence can achieve superior mixing
characteristics and reduce emissions. The development of advanced mixing technologies
requires accurate predictions of the spray characteristics. However, atomization is often
modelled using the Lagrangian approach with deterministic breakup models instead of
the higher-fidelity interface-capturing methods, such as Volume-of-Fluid (VOF), due to
their high computational cost. The breakup models used in state-of-the-art CFD and
developed specifically for liquid jets in crossflow (LJIC) rely on empirical constants
and/or correlations that need to be calibrated with experimental data, which is not
practical. The practicability of modelling LJIC could be improved by using a stochastic
secondary droplet (SSD) breakup model that does not require exhaustive calibration. A
better compromise between computational cost and accuracy could also be achieved by
coupling the Lagrangian and VOF approaches. However, very few studies have assessed
or validated their predictive capabilities for LJIC, especially for fuels and under more
representative gas turbine conditions.
This research aimed to improve the practicability of modelling turbulent liquid fuel jets
in crossflow (LFJIC) and to contribute to the knowledge of the Lagrangian and hybrid
approach through new assessment and validation work. Lower and higher-fidelity
modelling approaches for turbulent LFJIC were assessed and validated using
experimental data over a wide range of pressures, momentum flux ratios and Weber
numbers. This comprised an investigation of the effects of different sub-models and
boundary conditions on the flow properties, predictive capabilities, and computational
cost. This collaborative research between Cranfield University and Siemens Energy has
led to the development and validation of novel stochastic numerical methodologies as
well as a better understanding of LFJIC modelling. The hybrid resolved method proposed
offers superior predictive capabilities for the overall droplet velocities and droplet
diameters in the leeward region but is on average 17 times more computationally
expensive than the URANS Lagrangian methodology. The optimized stripping method
proposed reduces the cost of the hybrid approach by 78% and the average relative
difference between their predictions is less than 15%. Thus, their trade-offs between
accuracy and computational cost were deemed reasonable and guidelines were formulated
to help determine the most suitable methodology for future research work on turbulent
LFJIC. The research outcomes are already being used to hasten the design, development,
and delivery of novel low-emission gas turbine combustion systems.PhD in Aerospac
Insights into Alternaria in apple fruit causing mouldy core, external infection and mycotoxin production under retail and storage conditions
Get PDFApple fruit is widely consumed worldwide, but fungal contamination in the postharvest stage presents a significant food safety concern. This study evaluates the production and accumulation of Alternaria mycotoxins, including alternariol (AOH), alternariol monomethyl-ether (AME), and the modified forms (AOH-3-S, AME-3-S, AOH-3-G, AME-3-G), altenuene (ALT), tenuazonic acid (TeA), tentoxin (TEN), altertoxin I and II (ATX[sbnd]I, ATX-II), in Red Delicious apples under simulated retail and post-harvest conditions. Three Alternaria tenuissima strains (isolates 02, 31 and 36) were inoculated in apple fruit at two sites separately (core and exterior) and incubated at two temperatures (25 °C and 4 °C) for 1 and 9 months. Mycotoxin production was quantified using LC-MS/MS, revealing significant variability across strains and conditions. Isolates 02 and 36 exhibited significant temperature and site-dependent variability in mycotoxin production. Higher levels of AOH, AME, ALT, and ATX-I were produced at 25 °C and in the core. Long-term cold storage delayed fungal growth but did not prevent mycotoxin accumulation, raising concerns about the safety of processed apple products. These findings highlight the need for stricter monitoring of mycotoxins during post-harvest storage to mitigate health risks. The findings provide insights into their toxigenic capacity in vivo and highlight potential risks for food safety.This work was supported by by MYTOX-SOUTH®, Universidad de Buenos Aires [UBACyT 2018, 20020170100094BA], Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT), Argentina [PICT-2017-0907] and Subsidio para investigadores en formación de la Universidad de Buenos Aires 2020.International Journal of Food Microbiolog
A sustainable supply chain finance ecosystem: a review and conceptual framework
Get PDFSupply chain finance (SCF) is a set of instruments for optimizing working capital and improving supply chain efficiency. The evolving field of sustainable supply chain finance (SSCF) extends SCF with a growing focus on sustainability. While existing research has primarily focused on the economic benefits of SCF, its potential to generate broader sustainability benefits across environmental, social, and governance dimensions has received limited attention. Moreover, discussions on SSCF solutions and stakeholder interactions remain insufficient, necessitating further exploration to consolidate current research. This study seeks to explore the role of sustainability in SCF and proposes an SSCF ecosystem. A systematic literature review (SLR) of SCF and sustainability resulted in the analysis of 70 interdisciplinary journal papers published between 2008 and 2023. The SSCF ecosystem is defined as a collaborative network of stakeholders leveraging financial tools and sustainability metrics to create shared value and sustainability goals across the supply chain. By applying stakeholder theory and CIMO logic, the study develops a conceptual framework to explain how SSCF mechanisms and interventions produce desirable outcomes for stakeholders. Key influencing factors were identified across four sustainability dimensions—economic, environmental, social, and governance—along with core stakeholders, including buyers, financial institutions, and suppliers, supported by technology/logistics providers and ESG information providers. The study contributes by linking stakeholders to two distinct categories of SSCF solutions: buyer-centric accounts payable financing and supplier-centric accounts receivable financing. Lastly, it proposes future research directions by examining SSCF as an independent subject and capturing its links to traditional SCF.International Journal of Production Economic
Changes in land capability for agriculture under climate change in Wales
Get PDFLand capability assessments are key models that can identify current and future capacity of land for agricultural production. However, assessments of land capability under climate change do not fully consider climate-soil-crop interactions, are produced at scales too coarse for decision making and exclude key end users. We tackle these gaps by co-developing a predictive fine-scale spatial assessment of Agricultural Land Classification in Wales for baseline climate (1961-1990) and future climate scenarios. The findings revealed an increase in the proportion of land with better agricultural potential in 2020 (2010-2039) and 2050 (2040-2069) compared to the baseline, becoming more favourable for agriculture due to decreased soil wetness. However, by 2080 (2070-2099), there was a reduction in the proportion of higher grade and best and most versatile land for agriculture. During this period, an increase in accumulated temperature and decrease in rainfall during the growing season resulted in higher soil moisture deficits and increased risk of summer drought. We identified soil droughtiness as the most limiting factor for agricultural capability in 2080, resulting in a decrease in the best and most versatile land for agriculture (by 2 to 11% compared to the baseline). The transparency of the approach and prediction of land capabilities at local scale enabled effective policy implementation and decision making. The predicted future changes in land capability highlight that policy instruments used currently to protect high grade agricultural land should also consider the potential impacts of climate change.This project was part of the Climate, Capability and Suitability Programme funded by the Welsh Government through the European Agricultural Fund for Rural Development (EAFRD) from the Welsh Government Rural Communities - Rural Development Programme 2014–2020.Science of The Total Environmen
Anaerobic microbial core for municipal wastewater treatment — the sustainable platform for resource recovery
Get PDFThe requirement for carbon neutrality and bioresource recovery has shifted our views on water treatment from health and pollution avoidance to one of sustainability with water and nutrient circularity. Despite progress, the current process of wastewater treatment is linear, based on core aerobic microbiology, which is unlikely to be carbon neutral due to its large use of energy and production of waste sludge. Here, we outline a shift from aerobic to anaerobic microbiology at the core of wastewater treatment and resource recovery, illustrating the state-of-the-art technologies available for this paradigm shift. Anaerobic metabolism primarily offers the benefit of minimal energy input (up to 50% reduction) and minimal biomass production, resulting in up to 95% less waste sludge compared with aerobic treatment, which is increasingly attractive, given dialogue surrounding emerging contaminants in biosolids. Recent innovative research solutions have made ambient (mainstream) anaerobic treatment a ready substitute for the aerobic processes for municipal wastewater in temperate regions. Moreover, utilising anaerobic treatment as the core carbon removal step allows for more biological downstream resource recovery with several opportunities to couple the process with (anaerobic) nitrogen and phosphorus recovery, namely, potential mainstream anaerobic ammonium oxidation (anammox) and methane oxidation (N-DAMO). Furthermore, these technologies can be mixed and matched with membranes and ion-exchange systems, high-value biochemical production, and/or water reuse installations. As such, we propose the reconfiguration of the wastewater treatment plant of the futurewith anaerobic microbiology. Mainstream anaerobic treatment at the core of a truly sustainable platform for modern municipal wastewater treatment, facilitating circular economy and net-zero carbon goals.Partial funding was provided by the U.S. National Science Foundation (Award 2229857).Current Opinion in Biotechnolog
Data for Tracing the botanical origins of UK heather honey by relative quantification of plant DNA
No full textDate of data collection: 2021 - 2025
Geographic location of data collection: Cranfield University, College Road, Cranfield, MK43 0AL, UK.
This repository contains the following data files:
a) a.honey_Cq_RQ_DODD2025.csv :a dataset containing qPCR amplification (Cq value) for all honey samples , relative quantification calculation and the resulting class group.
b) b.BLAST_ling_DODD2025.pdf :complete in silico analysis of the Calluna vulgaris marker using PrimerBLAST.
c) c.BLAST_bell_DODD2025.pdf :complete in silico analysis of the Erica cinerea marker using PrimerBLAST.
DATA-SPECIFIC INFORMATION FOR: [a.honey_Cq_RQ_DODD2025.csv]
Number of variables: 15
Number of cases/rows: 271
Variable List: The Cq values from reaction 1-3 for trnL_P6 marker, The Cq values from reaction 1-3 for CV_trnL marker, The Cq values from reaction 1-3 for EC_trnL marker, The relative quantity (RQ) of ling, The relative quantity (RQ) of bell, The standard deviation (SD) of RQ of ling, The SD of RQ of bell, the final class of ling, the final class of bell.
Missing data codes: na: not amplified, N/A: not applicable
Specialized formats or other abbreviations used: ling: Calluna vulgaris plant, bell: Erica cinerea plant, final class calculated according to RQ value for ling or bell (dominant: > 0.45, secondary: 0.16 – 0.45, important minor: 0.03 – 0.16, trace: 0.03 – 0.01, sporadic: 0.01 – 0.001 and none: <0.001)
Grant: BB/T008776/1Heather 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. Therefore, 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 94% 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.Biotechnology and Biological Sciences Research Council (BBSRC
Enzyme-free pretreatment of brewer’s spent grain for xylose recovery for potential xylitol production
Get PDFBrewer’s spent grains (BSG), a by-product in beer brewing, have historically been relegated to animal fodder. This study delves into the untapped potential of BSG as a valuable source of fermentable sugars, specifically xylose. Proximate analysis confirmed the presence of xylan-rich hemicellulose (21.5 ± 0.32%) in BSG, making it ideal for xylose production. The FTIR spectrum of BSG confirmed peaks at 900–950 cm⁻¹ corresponding to hemicellulose xylan. A combined pretreatment of BSG by hydrothermal (110 °C) and acid hydrolysis (100 °C) resulted in 50.11 ± 0.15% of reducing sugar recovery as quantified by Lane and Eyon method again reconfirmed by HPLC with 48.15 ± 0.05 g/L of xylose. GC-MS analysis of pre-treated BSG hydrolysate revealed presence of some inhibitory compounds with mass spectra viz. Levoglucosenone, 9,12-octadecadienoic acid, n-hexadecenoic acid and furfural derivatives. Further the BSG hydrolysate obtained after combined pretreatment was further used as a carbon source in addition to other ingredients of medium. A preliminary fermentation trial with Pichia fermentans was carried out at 30° C, at pH 7.0 for 24 h and resulted in 6.13 ± 0.05 g/L xylitol production at 30 °C at 150 RPM. The results validated the effectiveness of the pre-treatment in maximizing fermentable sugar recovery and give conformity for further optimization of xylitol production making it enzyme free and cost-effective approach.Graphical AbstractBiotechnology for Sustainable Material
Instance-specific heuristic learning for scalable UAV path planning
Get PDFEfficient and scalable path planning is critical for autonomous UAVs navigating complex, obstacle-dense environments. Traditional heuristic search algorithms like A∗ and Focal Search often face challenges with scalability and adaptability in such scenarios. We present a framework that leverages Transformer-based heuristic learning to predict Path Probability Maps (PPM), which are probabilistic grids that indicate the likelihood of each cell being part of an optimal path from start to goal. This significantly enhances search efficiency and solution quality by guiding the search towards high-probability regions. Trained on diverse motion planning datasets and tailored for UAV-specific challenges, our method reduces computational overhead while maintaining near-optimal path quality. Empirical results demonstrate the framework’s effectiveness, solving over 50% of scenarios optimally and reducing node expansions by a factor of 2. Additionally, the framework exhibits robust scalability across varying instance sizes, highlighting the potential of instance-dependent heuristic learning to transform UAV path planning for real-time applications.AIAA Aviation Forum and Ascend 202
Bioremediation of oil-rich wastewater: managing sewer Fats, Oils, and Grease (FOG) deposits with energy uncoupler product
No full textBajón Fernández, Yadira - Associate SupervisorThe disposal of Fats, Oils, and Grease (FOG) down drains in both residential and
commercial settings results in the buildup of these substances within sewer systems.
This accumulation can ultimately lead to blockages and subsequent sewer overflows,
posing significant challenges for the water industry. The impacts include potential
customer dissatisfaction, negative effects on business operations, and regulatory fines.
Effectively managing FOG is a complex issue, and finding viable solutions is paramount.
Solutions leading to an alleviation of this problem are of great value, nonetheless, no
uniform approaches have been established so far, and the existing measures remain
insufficient. FOG bioremediation is emerging as a promising alternative to traditional
sewer cleaning methods, but effective, targeted implementation requires higher scientific
understanding of FOG deposit formation and modes of action of biological products.
This research introduces a novel approach to understanding and addressing FOG
deposit formation and treatment. It does so by tailoring these methods to the specific
stages of FOG deposit development and utilizing an energy uncoupler product—
specifically, a combination of yeast protein extract with surfactants.
To substantiate the effectiveness of this approach, comprehensive trials were
conducted. These trials encompassed synthetic solutions to simulate deposit formation,
preformed synthetic deposits, as well as real deposits collected from the UK's sewerage
network. The results of the thesis question and provide an alternative to the currently
accepted model of FOG deposit formation through saponification. Instead, the work
proposes a two-stage model based on the initial starch-lipid complexation followed by
growth through accumulation of fats, lipids, carbohydrates, proteins, and calcium. The
study then assessed the uncoupler treatment's impact through two mechanisms of
action, i.e., inhibition and rehabilitation, in terms of reducing deposit mass and removing
organic fractions present in wastewater. The results provided compelling evidence for
the advantageous use of metabolic uncouplers in minimizing FOG deposit formation
within sewer systems. Finally, the economic assessment of using the metabolic
uncoupler revealed its financial feasibility for both planned and unplanned sewer
cleaning procedures through the reduced maintenance that occurred when using it.Engineering and Physical Sciences Research Council (EPSRC)STREAM EngD Programm
On residual tensile strength after lightning strikes
Get PDFThe data that has been used is confidential.The study of post lightning strike residual strength is still relatively underdeveloped in the literature. Different approaches including in-plane compression or flexural testing have been used, but in-plane tensile loading post-strike has not been studied in detail. Although previous attempts have been made to determine the residual strength using Compression-After-Lightning (CAL) tests on composite laminates, these have been limited and not readily applicable under tensile loads. Therefore, this work completes Tension-After-Lightning (TAL) testing at 75 kA on composite laminates, a more realistic peak current than previously reported for TAL tests, to assess the knock-down in strength post-strike. The measured average TAL failure stress was 716 MPa, a reduction of 23 % from the baseline tensile failure stress of 929 MPa in the literature. This confirms a similar knock-down factor reported at lower peak currents (e.g. 50 kA), but the new TAL specimen geometry ensures that the lightning damage is contained within both the lightning and TAL specimen widths. In addition, a new Finite Element (FE) based virtual test was conducted, considering 0° ply splitting, and validated with the TAL tests herein. The TAL simulation predicted the residual tensile failure stress well, within 6 % of the measured value.Composites Part A: Applied Science and Manufacturin