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Propulsion integration design and evaluation for novel aircraft configurations
Get PDFTo comply with the future environmental requirements for the aviation industry, it
is necessary to move towards more efficient aircraft and propulsive systems. Within
this context, different novel aircraft concepts have been introduced to increase overall
propulsive efficiency compared with the current technologies. A common characteristic
between these concepts is the close integration of the propulsive system within
the airframe. As a consequence, the impact of the propulsion integration on the
aerodynamic performance of the aircraft is expected to increase in comparison with
the conventional wing-mounted podded engines. However, with a few exceptions,
for these new configurations the impact of the propulsion integration on the aerodynamic
performance has not been sufficiently quantified. The aim of this research
is to establish the methods for the aerodynamic design of the propulsion integration
of the novel embedded propulsion systems. These methods are then used, for an
example configuration, to quantify the impact of the propulsion integration in the
overall aerodynamic performance and characteristics.
A systematic design methodology was developed for the aerodynamic analysis of
embedded propulsion systems. This methodology includes the parametric definition
of the geometry, the aerodynamic evaluation of the propulsor, and a tailored postprocessing
approach. An aft-mounted annular boundary layer ingestion propulsor
for a medium-range single-aisle aircraft is used as a sample case study. A hierarchical
approach with an increasing level of fidelity was applied to determine the modelling
requirements for the embedded propulsion systems. This involved low order methods
for drag prediction and computational fluid dynamics (CFD) methods. The CFD
methods included two different fan approaches (one-dimensional and through-flow),
as well as 2D axisymmetric and 3D models. To understand the limits of the design
space, the design methodology was combined with a multi-objective optimisation
(MOO) approach based on evolutionary algorithms.
In a preliminary analysis, power savings for the whole aircraft between 3-11% were
predicted due to the integration of the aft-mounted propulsor. Compared with the
CFD analyses, low order models for the prediction of the aerodynamic performance
found in the open literature overpredicted the power savings in approximately a
50%, making them unsuitable for the evaluation of the aerodynamic performance
in embedded systems. A comparison of the modelling fidelity of the different CFD
approaches shown a reduction of approximately 2% of the power savings from the
original 3-11%, when 2D axisymmetric models are applied instead of more representative
3D approaches. However, the 2D axisymmetric models had about 1% of
the computational cost of the 3D versions. The application of a more representative
through-flow fan model also increased the predicted power savings by up to 1-1.5%
when compared with a one dimensional fan.
The location of the aft-mounted propulsor was found to have a significant impact on
the aerodynamic performance of the embedded propulsor and the predicted power
savings. Relative to the overall benefits in the power consumption of ∼ 11%, variations
of approximately 4-5% on the predicted power savings are observed with the
change of the propulsor axial and radial location. Locations near to the fuselage
centreline are preferred. Short aft-fuselage lengths with a low fan radius of the aft mounted
propulsor provided the highest thrust contribution and power savings. The
more detailed design of the housing components (intake, nacelle and exhaust) of the
aft-mounted propulsor has a second order impact in comparison with the propulsor
location. At a fixed propulsor position, an increase of up to 1.5% of the power
savings was obtained with the MOO of the aerodynamic design of the propulsion
integration. From these changes, approximately one-third was obtained with the
optimisation of the exhaust design, while the remaining benefits were obtained with
the optimisation of the aft-fuselage, intake and nacelle geometries.PhD in Aerospac
Competence in digital forensics
No full textThose practising in the field of digital forensics must be competent to conduct the work they carry out, and such competence must also be evidenced and assessed. Those seeking to demonstrate staff competence must consider what tasks and roles it is being sought for, how it is achieved, what is an acceptable level of performance for a task, and how to evidence and assess any claimed competence. This work intends to explore the multifaceted nature of competence within the field of digital forensics, examining how it is developed, assessed, and maintained in an era characterised by continuous technological advancement. Discussions are also linked to the requirements defined in the accreditation framework ISO/IEC 17025:2017 which governs the digital forensic landscape in England and Wales. We hope to contribute to the ongoing discourse on elevating standards and fostering excellence in the science of digital forensics.Forensic Science International: Digital Investigatio
Exploring advanced functionalities of carbon fiber-graded PEEK composites as bone fixation plates using finite element analysis
Get PDFThis study aims to address the challenges associated with conventional metallic bone fixation plates in biomechanical applications, such as stainless steel and titanium alloys, including stress shielding, allergic reactions, corrosion resistance, and interference with medical imaging. The use of materials with a low elastic modulus is regarded as an effective approach to overcome these problems. In this study, the impact of different types of chopped carbon fiber-reinforced polyether ether ketone (CCF/PEEK) functionally graded material (FGM) bone plates on stress shielding under static and instantaneous dynamic loading was explored using finite element analysis (FEA). The FGM bone plate models were established using ABAQUS and the user’s subroutine USDFLD and VUSDFLD, and each model was established with an equivalent overall elastic modulus and distinctive distributions. The results revealed that all FGM bone plates exhibited lower stress shielding effects compared to metal bone plates. Particularly, the FGM plate with an elastic modulus gradually increased from the centre to both sides and provided maximum stress stimulation and the most uniform stress distribution within the fractured area. These findings offer crucial insights for designing implantable medical devices that possess enhanced mechanical adaptability.This research was funded by the China Scholarship Council: 202006370083Material
Devices and methods for wet gas flow metering: a comprehensive review
Get PDFWet gas is commonly encountered in various industries, including energy, chemical, and electric power sectors. For example, natural gas extracted from production often contains small amounts of liquid, such as water and hydrocarbon condensates, which classifies it as wet gas. The presence of liquid within the gas poses challenges for accurate flow measurement. To improve the performances of wet gas flow metering methods, significant research and development efforts have been invested into the wet gas flow metering technologies due to their vital importance in the production, transfer, and trade benefits.
This paper presents a comprehensive overview of the recent development of wet gas flow metering. Firstly, a comprehensive discussion of the Lockhart-Martinelli parameter (Xlm) and its relation to the gas void fraction (Óg) is presented, which was mostly overlooked in previous wet gas research work. The occurrence of various flow patterns in wet gas conditions at different orientations (horizontal and vertical) was explored. Following an investigation of pressure impact on the wet gas flow patterns and development of the wet gas regions, a different test matrix for further research work was suggested. After a novel classification of wet gas measurement methods, the paper offers a detailed comparison of differential pressure (DP) meters including Venturi, Cone meter, and orifice meters, by considering both liquid and gas flow rate measurements. Secondly, the paper discusses and compares vortex flow meters, Coriolis and ultrasonic meters in comparison to DP meters. Notable phase fraction meters are also examined and compared to one another. Thirdly, the paper reviewed the concept of existing and potential hybrid wet gas meters, conducting a detailed discussion and comparison with commercial solutions by evaluating their ranges and accuracies. This assessment provides valuable insights into the capabilities of these hybrid meters, highlighting their potential to enhance the measurement of wet gas flow rates.Flow Measurement and Instrumentatio
Examining thermally induced movement of the fatal fire victim
Get PDFInvestigating a fatal fire scene comprises analysis not only of the fire’s development to identify the point of fire origin and ignition source, but analysis of a victim’s position and their relationship within the scene. This work presents both qualitative and quantitative results from experimentation investigating the effect of a real fire environment on the human body, and how the position of a victim at the post burn investigation stage may be significantly different to the position at fire ignition. Qualitative observations were undertaken on the burning of 39 compartment and vehicle scenes from ignition through to suppression, each containing a human cadaver. The results of analysis question the validity of previous work based on cremation observations. Quantitative results were produced by recording 13 points on the body on the X, Y and Z axis, both pre and post burn on a smaller dataset of ten compartment burns. Results have enabled a more robust assessment of thermally induced movement of the body within the scene along each axis, evidencing that pugilism is not the universal reaction of the fatal victim to thermal exposure, with extension of the upper limbs far more common than has been previously reported.Forensic Science Internationa
Response of a coriolis gas flow meter to steady and transient wet gas flow conditions
Get PDFCoriolis devices are continuously evolving to meet the demands of different conditions, such as wet gas flow. However, their application in wet gas flow has not yet been thoroughly explored. The impact of steady flow disturbances on Coriolis flow meters is well-documented, and empirical compensation or correction methods can be implemented accordingly. However, there has been inadequate investigation into the response of Coriolis meters under transient flow conditions and their comparison with steady flow in a wet gas. In this study, a Coriolis device was horizontally installed in a 50 mm pipe diameter. The experimental fluids consisted of air and water, with Lockhart-Martinelli (XLM) values ranging from 0.02 to 0.40. Steady and transient flow conditions at different gas and liquid flow rates were studied. The findings demonstrate the capability of standard deviation (STD) in distinguishing transient flow from steady one. Additionally, a strong correlation was observed between XLM and gas Over-Reading (OR) across various gas flow rates and XLM values. This correlation is particularly evident for XLM < 0.1. At extremely low liquid loading (XLM < 0.05), the average percentage error remains below 7 % even without the utilization of any correction models. Furthermore, the impact of different sensor installations, which had been largely overlooked in previous studies, was investigated.9th World Congress on Momentum, Heat and Mass Transfe
Rapid enzymatic assays for fecal contamination in aquatic environment: challenges, advances and prospects
Get PDFRoutine monitoring of sanitation and hygiene to identify fecal contamination in aquatic environments is an effective means to prevent threatening disease transmission. Compared to immunological or genetic methods performed in a central lab, enzymatic assays are considered simple, quick, cost-effective and thus promising for in-field (near) real-time detection. However, the long detection time for mildly polluted samples is a major obstacle to its deployment as an early warning system. Here, the challenges faced by the assays in real environmental sample measurements are summarized, followed by the current status of their field applications. Furthermore, the likelihood and ways are discussed for significant assay improvements using state-of-the-art synthetic biology technologies. Rapid advances in synthetic biology such as various new enabling tools for precise biomolecular manipulation and cell-free expression systems have great potential to address the present bottlenecks of the enzymatic assays, paving the way for better early warning strategies and performance.TrAC Trends in Analytical Chemistr
Ammonia for civil aviation: a design and performance study for aircraft and turbofan engine
Get PDFThe 2050 net zero targets for aviation to decarbonize the industry means that solutions need to be delivered that can help achieve those targets. Transitioning to zero carbon aviation fuel is an effective solution to achieve those targets. This research article aims to highlight the potential design and performance implications of using Ammonia as a zero-carbon fuel for civil aviation through a retrofit case study conducted for an Airbus A350-1000 equivalent aircraft. The impacts on both turbofan design and aircraft payload-range capability are presented. A feasibility study of using Ammonia as a Hydrogen carrier for civil aviation is also presented. The turbofan design impacts, and payload range capability are assessed using Cranfield University’s in-house gas turbine performance tool TURBOMATCH and NASA FLOPS respectively. A 3-point turbofan cycle design strategy is utilized for redesigning turbofan engine cycles using Ammonia as a fuel. Ammonia fuel conditioning assessment is made using REFPROP to investigate its impact on turbofan design. Utilizing pure Ammonia as an aircraft fuel can provide significant turbofan redesign opportunities. Fuel conditioning assessment revealed that for a 430 kN thrust class engine, 2.1 MW of thermal power is required to condition Ammonia fuel at take-off. As a result, various strategies to condition the fuel and its significant impact on turbofan design are presented indicating fuel conditioning as a major design driver for Ammonia fuelled turbofan engines in the future. Although upon initial preliminary assessment, Ammonia utilized as a Hydrogen carrier showcased potential by providing additional mission range capability when compared to a pure Ammonia burning aircraft, the significant thermal energy required to crack (decompose) Ammonia into Hydrogen highlighted the challenges at aircraft mission level and Hydrogen turbofan design implications. It is found that energy requirement (power) to crack Ammonia into Hydrogen are significant which is approximately an order of magnitude higher than Ammonia fuel conditioning itself.The author would like to acknowledge Rolls-Royce plc and Cranfield University for funding this doctoral program.Energy Conversion and Managemen
Automated Microfluidic Analysis of CUP-2 UOC for Forensic Applications
Get PDFPoster contribution to the Defence and Security Doctoral Symposium 2023 EPSR
Critical assessment of the lattice Boltzmann method for cavitation modelling based on single bubble dynamics
Get PDFThe lattice Boltzmann Method (LBM) is recognised as a popular technique for simulating cavitation bubble dynamics due to its simplicity. In the validation of LBM results, the Rayleigh-Plesset (R-P) equation is commonly employed. However, most studies to date have neglected the impact of simulation settings on the predictions. This article sets out to quantify the impact of LBM domain size and bubble size, and the initial conditions of the R-P equations on the predicted bubble dynamics. First, LBM results were validated against the classical benchmarks of Laplace’s law and Maxwell’s area construction. LBM results corresponding to these fundamental test cases were found to be in satisfactory agreement with theory and previous simulations. Secondly, a one-to-one comparison was considered between the predictions of the LBM and the R-P equation. The parameters of the two models were matched based on careful considerations. Findings revealed that a good overlap between the predictions is observable only under certain conditions. The warming-up period of the LBM simulations, small domain size, and small bubble radius were identified as key factors responsible for the measured differences. The authors hope that the results will promote good simulation practices for cavitation simulation including both single bubbles and bubble clusters.Discover Applied Science