DSpace 7

DSpace is the world leading open source repository platform that enables organisations to:

easily ingest documents, audio, video, datasets and their corresponding Dublin Core metadata
open up this content to local and global audiences, thanks to the OAI-PMH interface and Google Scholar optimizations
issue permanent urls and trustworthy identifiers, including optional integrations with handle.net and DataCite DOI

Photo by @inspiredimages

Communities in CERES

Select a community to browse its collections.

Now showing 1 - 5 of 20

Aerospace and Aviation 45
AI, Robotics and Space 43
Alumni 3
Cranfield Alumni output
Archives 103
Archival Material
Automotive, Energy and Photonics engineering 31

Recent Submissions

Access status: Open Access ,
Trajectory optimization with sparse gauss-hermite quadrature
(Cranfield University, 2023-04) Park, On; Shin, Hyo-Sang; Tsourdos, Antonios
This thesis aims to innovate knowledge on the trajectory optimization problem for aerospace applications by adopting a numerical integration in optimal control designs. Quadrature point scheme is considered to substitute a derivative of an optimal cost-to-go function and system dynamics approximated by Gaussian Quadrature rule. Based on the Differential Dynamic Programming (DDP) algorithm, a sequence of optimal control input is derived by sparsely chosen quadrature points with the Smolyak’s rule over an exponential weighting function on the Gaussian quadrature, called as Sparse Gauss-Hermite Quadrature (SGHQ). The sampling points propagated via system dynamics computes the mean and covariance of a probability distribution of the value function avoiding a numerical differentiation in the DDP. This approach improves an accuracy and robustness against the numerical calculation in the highly nonlinear environment despite the less number of the quadrature points compared with the fully composed by Gauss- Hermite Quadrature. Besides, the number of sampling points can be determined by Smolyak’s rule definitely, while the other sampling point-based approach chooses by heuristic/empirical method such as a trial and error. The proposed method is carried out and validate via numerical simulation: a fixed-wing aircraft controller and missile guidance. Considering a stochastic environment and control policy, trajectory optimization problem can be extended to a stochastic trajectory optimization and maximum entropy problem by adding an entropy term in a deterministic trajectory optimization problem: a Guided Policy Search (GPS). This entropy term in a stochastic problem enables to prevent a control policy from falling into local minima by maximizing exploration in the given unknown environment, and improves robustness to respond to a potentially flexible environment. A local policy is updated by DDP framework where the SGHQ-DDP can be implemented to find a mean and covariance of policy distribution by solving the soft Bellman equation. The numerical simulation shows the feasibility of the SGHQ-GPS method under an unknown system dynamics under the fitted model.
Access status: Open Access ,
Introduction of social benefits to the tera – gas turbines and pipelines
(Cranfield University, 2023-04) Ojo, Oluwatayo Babatope; Pilidis, Pericles; Igie, Uyioghosa
The aim of this work is the techno-economic and environmental risk analysis (TERA) of the Trans-Saharan Gas Pipeline on gas turbine compressor stations. A pipeline project encompasses many aspects, viz., choice of compressor station location, power of each compressor station, compressor station availability, pipeline sizing, and it includes socioeconomic impacts. Therefore, this research considered the impacts of engine availability, compressor station location, and socioeconomic impact in the TERA for pipelines while optimising for the lowest lifecycle cost. The pipeline and gas compressor modules were evaluated considering segmented pipe length, elevation, and station location ambient temperature variation at varying flow conditions. The design and off-design points performance of the selected gas turbine models were simulated using Turbomatch to obtain essential performance data required for the techno socio- economic analysis. The unit availability was evaluated based on a developed local maintenance schedule and failure rate retrieved from literature studies. The analysis considered the social impacts and benefits of compressor station locations. A scenario-based techno socio-economic analysis was performed to show the sensitivities of the compressor station and pipeline systems to social and technical aspects of the project in terms of social benefits and availabilities. The economic model was developed based on social benefit algorithms and the variation in compressor station location ambient temperatures at varying flow conditions. Results show compressor station system availabilities of 0.2542, 0.4657, and 0.9926 with corresponding lifecycle costs of $22.22 billion, $23.05 billion, and $24.11 billion assuming a 15% discount rate for scenarios 1, 2, and 3, respectively. An increase in availability leads to a corresponding increase in the lifecycle cost estimate. The employment and road benefit ratios would increase by a factor of 10 and reciprocal of new locations. This ratio is for every 10 km decrease in the distance at each station location. Results show the significance of the modelling and optimisation approaches utilised in this research for compressor station locations optimisation of the integrated pipeline TERA. This will guide decision-makers on the ultimate selection of engine configurations that will give the optimum lifecycle cost and socio-economic benefits at the optimised station locations.
Access status: Open Access ,
Dataset relating to Arsenic contamination of rainfed versus irrigated rice
(Cranfield University, 2025-07-23) Ingram, Ben; Kirk, Guy; Corstanje, Ron; Simmons, Robert
Arsenic (As) contamination of rice remains a major human health issue in Asia. Most research has been on irrigated rice. However much of the projected increase in global rice demand over coming decades must be met by rainfed lowland systems, for which As relations are poorly understood. We present the most comprehensive survey to date of As in rice in farmers’ fields across Bangladesh, covering both irrigated and rainfed systems. We collected rice grain and soil at 943 sites in the three rice growing seasons: irrigated Boro, rainfed Aus, and longer-duration rainfed Aman. Grain As concentrations increased in the order Aman << Boro < Aus with 2, 25 and 41 % of the sites exceeding permitted thresholds, respectively. The greater concentration in Aus than Boro challenges the accepted wisdom that contaminated irrigation water is the main source of As. The main growth and grain filling periods, when most As is taken up, coincide in Aus with the peak of the monsoon rains, suggesting a link between rainfall and high grain As. We suggest this is due to stronger soil reducing conditions and hence As solubility during peak rainfall. We discuss implications for rainfed lowland rice across Asia and mitigation options.
Access status: Embargo ,
Design and analysis of sandwich structure for the application on FAR25 wing
(Cranfield University, 2021-12) Naik, Vivekanand K.; Wenli, Liu; Jamshidi, Jafar
With the growing concern towards global warming and increase in fuel prices, many countries advocate stringent environmental laws to restrict any further damage to the environment. The new laws will affect how the future vehicles are designed. The aerospace industry is also one of the main contributors of pollution. To design better fuel-efficient aeroplanes, aero industry is switching to weight efficient materials. Since last few decades the aerospace industry is shifting from isotropic materials to composite materials to design weight efficient structures. The structures made up of composite materials are mostly in two different forms such as monolithic composite materials used on primary structures and composite sandwich materials which are commonly seen on the secondary structures. The research aims at investigating the sandwich structure as the potential material for the application on FAR25 type wing primary structure. The transport category airplanes with greater than 19 sets or the maximum take of weight (MTOW) is greater than 8618kg are referred to FAR25 type aeroplanes. In the first phase of the research, the focus is to assess the literature to find research gaps within the sandwich structures along with feedback from Airbus Research and Technology (R&T). In second phase, the focus is to investigate the stiffened panel design which is based on the current Airbus single aisle aeroplane. The review of sandwich structures and its current application on FAR25 structures along with the current research and development of sandwich material technology is conducted. The different failure modes of the sandwich structures are also investigated. In the third phase, parametric study and optimization of stiffened panel and sandwich panel is performed within the range of operational loads. In addition, the influence of core properties in improving the structural efficiency of sandwich structure is investigated. The research also focused on understanding the efficiency of different sandwich joints. In the final phase of the research the study looks into the design of hybrid/variable stiffness core to help tailoring core properties to improve the structural efficiency of sandwich panel. The research study demonstrated the importance of core properties in designing the efficient sandwich panel as potential material for the application on FAR25 primary structure. Investigation of novel variable core design has demonstrated how the tailoring of core properties can influence the overall performance of sandwich structure so that the core can be tailored as per different application. From the research it has shown that the sandwich core with single property structure can be still used on secondary structure whereas the tailored core design for the primary structure on FAR25 type aeroplanes. It is also shown that a better manufacturing process can add considerable value for sandwich materials.
Access status: Embargo ,
Propulsion integration design and evaluation for novel aircraft configurations
(Cranfield University, 2022-10) Matesanz Garcia, Jesus; MacManus, David G.
To 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.