A novel standalone solar-driven agriculture greenhouse desalianation system

Postdoctoral Research Project: Dr Mohammad Akrami

Countries in the Middle East and North Africa (MENA) region are suffering from the scarcity of freshwater resources. With the economic development and population growth, planning additional water supplies is critical for this region. Desalination of saline water is considered as a strategic alternative for water supply in the MENA region. On the other hand, open field agriculture in such conditions is not economical, particularly with high ambient temperature and solar intensity. Agricultural greenhouses (GH) present a suitable alternative for growth of different plants for the region. In most cases, GHs can reduce about 90% of irrigation water demand compared to open field agriculture. With the availability of high solar energy, integration of solar, GH and desalination systems can generate energy from Photovoltaic/Thermal (PV/T) panels and fresh water in a sustainable manner. This two-year project is funded by British Council (BC) in the UK (Grant ID: 332435306) and the Science & Technology Development Fund (STDF) (Grant ID: 30771) in Egypt under the Newton-Musharafa funding scheme.

Contact: a.a.javadi@exeter.ac.uk

Buckle pattern formation in modern materials

Work is being undertaken to study the behaviour of structures in which induced instabilities cause elastic buckling. The scale of the structures to which this is applicable is from the everyday macroscopic scale down to nanoscale mechanics of novel materials. The latter could lead to the development of new sensors and devices for diagnosing various large-scale mechanical behaviours.

Contact: m.k.wadee@exeter.ac.uk

• Zhao, Y., Cao, Y., Hong, W., Wadee, M. K., & Feng, X.-Q. 2015. Towards a quantitative understanding of period-doubling wrinkling patterns occurring in film/substrate bilayer systems. Proc. R. Soc. Lond. A 471(2173): 20140695. Available online.
  
  
• Wang, C. G., Liu, Y. P., Al-Ghalith, J., Dumitrică, T., Wadee, M. K., & Tan, H. F. 2016. Buckling behavior of carbon nanotubes under bending: from ripple to kink. Carbon, 102, 224-235. Available online.
  
  
• Wadee, M. K., Lloyd, D. J. B., & Bassom, A. P. 2016. On the interaction of uni-directional and bi-directional buckling of a plate supported by an elastic foundation. Proc. R. Soc. Lond. A 472(2188): 20150873. Available online.
  
  
• Liu, Y. P., Wang, C. G., Tan, H. F., & Wadee, M. K. 2016. The interactive bending wrinkling behaviour of inflated beams. Proc. R. Soc. Lond. A 472(2193): 20160504. Available online.

International links include with the Harbin Institute of Technology (HIT), China. The China Scholarship Council (CSC) funded a Ph.D. student (Zihui Zhao) from HIT to visit the University of Exeter for a year in 2017-18.

Thin layer (elastic plate) under biaxial compression, Px and Py, supported by an elastic substrate. With fixed edges along the x direction and periodic boundary conditions along the y direction.

COLBE

The EPSRC funded project titled "The creation of localised current and future weather for the built environment" working with the University of Bath and Newcastle University. The aim of this project will be to see if a method can be devised that is capable of creating local weather from 2015 to 2080 covering the whole UK at a resolution of 5km, and to include within this files that represent various excursions from the mean: e.g. heat waves and cold snaps. 

For further information, visit our project website.

Contact: m.e.eames@exeter.ac.uk

Computational and Experimental Fluid Dynamics (CFD and EFD) analysis of ocean renewable energy convertors

PhD Project: Mohammad Hassan Khanjanpour

Due to the increase of price for energy from fossil fuels as well as the harmful impacts they have on the environment, there is a growing shift towards clean energy like ocean power, wind, biomass, geothermal and solar which have enormous potential for providing vast amounts of energy required by humans. Ocean provides a renewable source of energy with the advantage of being predictable many days in advance, stable during day and night, and significantly greater in its energy density compared to wind and solar energies. Although advantages of energy generated from the ocean is appealing, the potential of ocean power systems has not been researched in great detail. The development of ocean-powered systems has been limited due to technological limitations of energy harvesting and transporting. In this project, some of ocean power convertors are analysed both numerically and experimentally with the aim of improving the systems.

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EFD analysis (Hydraulic Laboratory of University of Exeter)

CFD analysis

Developing a risk assessment model using fuzzy logic and a Canadian case study to assess groundwater contamination from unconventional gas development in the UK

PhD Project: Olivia Milton-Thompson

Hydraulic fracturing is a viable method for extracting a wealth of natural gas from shale rock and has recently begun production in the UK. The process took off in the US but brought with it controversial debates over environmental protection. To feel confident in applying this technique to an apprehensive population in the UK, it is important to consider the science and engineering involved in the process. This project focuses on assessing the risks to groundwater contamination through well integrity failure pathways during both the injection and producing stages of an onshore gas-producing hydraulically fractured well. Data is often limited or confidential in the oil and gas industry so to understand the pathways with which gas can reach groundwater through integrity failure, event and fault trees are developed and quantified using both numerical and fuzzy logic approaches. The risk models for the injection and producing wells are built using a case study in British Columbia, Canada and discussions around the application of the model framework to the UK are vital for the UK shale gas industry.

Development of an assessment procedure for seawater intrusion mitigation

PI; Funded by Royal Society; £12,000 (with National Taiwan University).

Contact: a.a.javadi@exeter.ac.uk

Fatigue life monitoring for steel bridges

This research uses combine detailed finite element models of fatigue-critical connections and in-service strain measurements that capture the real-time shear, flexure, and axial demands of the connections to estimate accurately the in-situ hot spot/nominal stresses. The developed approach enables much more reliable assessment of fatigue life than is possible by current methods. It also enables predicting hot spot and nominal stresses at un-instrumented connections by combining numerical models with real-time measurements from a few instrumented connections. The research has proven the methodology using in-service measurements from three full-scale bridges – 2 rail and 1 road bridge. It has also demonstrated that the methodology can be integrated within a measurement interpretation platform for continuous bridge monitoring.

Contact: p.kripakaran@exeter.ac.uk

GeoRes - Geomaterials: from waste to resource

Principal Investigator: Prof. Akbar Javadi

GeoRes is a Marie Skłodowska-Curie Research and Innovation Staff Exchange (RISE) project, aimed to develop innovative solutions for the reuse of waste geomaterials generated by construction and mining industries across Europe and worldwide.

The project involves a network of 17 partners, including 6 universities from Europe (University of Exeter in the UK, University of Lorraine in France, University of Cassino in Italy, Lulea University of Technology in Sweden, Norwegian Geotechnical Institute in Norway, and Greenland Institute of Natural Resources in Greenland); 5 European Companies (Ginger CEBTP in France, Ramböll in Sweden, Ecoloop in Sweden, Horizon Consulting Engineers (HCE) in the UK, and Synopsys in the UK); and 6 universities outside Europe (École Polytechnique de Montréal in Canada, Monash University in Australia, Universidad de los Andes in Colombia, Universidade Federal do Rio Grande do Sul in Brazil, Iran University of Science and Technology in Iran and Institute of Rock and Soils Mechanics from the Chinese Academy of Science in China).

GeoRes develops protocols, software and tools to improve the engineering characteristics of waste geomaterials, and to guarantee the level of performance over the service life of geostructures considering site-specific conditions.

Further information is available on our website.

Contact: a.a.javadi@exeter.ac.uk

Investigation of saltwater intrusion in heterogeneous coastal aquifers in arid regions

PhD Project: Samia Saad

In arid coastal regions, groundwater aquifers, as an important source of freshwater, are threatened due to overexploitation to fulfil increasing water demand, as well as land use change, and the effects of climate change and sea level rise. This project involves the development and application of 3D finite element models to simulate sea water intrusion (SWI) considering various influencing factors. The results of the numerical modelling are used to propose practical methods for control and management of seawater intrusion. The Wadi Ham aquifer in the United Arab Emirates and the Nile Delta aquifer in Egypt are considered as case studies. Different sustainable SWI management scenarios are developed and applied to the study areas. Surrogate modelling and optimization techniques are used to evaluate the efficiency of different management scenarios and address the uncertainty in model predictions. The effects of natural and anthropogenic activities and future conditions, including changes in the natural recharge, and water and irrigation demands as well as sea level rise are studied.

Wadi Ham Study Domain & Boundary Conditions

A three-layer model of Wadi gravel and sand underlain by consolidated rocks of Ophiolite sequence. Unstructured mesh of 69880 triangular prisms.

Low carbon building materials

Waste and co-products management is a pressing issue, as well as the need for low cost, low carbon, safe and locally available building materials with improved thermal insulation properties.

The 2008 Climate Change Act declares a target reduction of the UK’s greenhouse gas emissions by at least 80% (from the 1990 baseline) by 2050. The built environment is responsible for some 40% of energy consumption and 36% of CO2 emissions. Energy consumption, and associated greenhouse gas emissions, is derived from whole life cycle, including manufacture of products, construction, maintenance and disassembly (e.g. embodied energy) as well as operational energy during building’s use.

A £18k funding from the GW4 alliance has been secured by Dr Vinai and Dr Eames for the set-up of the research community “Circular economy for affordable, low-carbon secondary raw materials” in partnership with Universities of Bath, Bristol and Cardiff.

Novel materials need to ensure their performance also in terms of durability. The microstructure of the material drives the paths that water and air use for infiltrating the matrix. Dr Vinai recently obtained a £48k grant from EPSRC Early Career Researcher Capital Fund 2019 for the procurement of an environmental chamber for controlling moisture, temperature, CO2 content for conditioning and testing, and a mercury intrusion porosimeter (MIP) for assessing the porosity, bulk and apparent density, particle size and pore related properties of developed materials.

The NERC GW4+ DTP NPIF is currently funding a PhD studentship for the project “Development of bio-based, low carbon and low cost building materials with improved thermal and acoustic properties – harvesting the potential of vegetal fibres”, under the supervision of Dr Vinai.

Contact: r.vinai@exeter.ac.uk

Managing debris risks for local authority bridges

This project funded by an EPSRC Impact Acceleration Award (IAA) and Devon County Council aims to embed research findings on assessing scour and hydrodynamic effects of debris blockage within current bridge management practice. Specifically, using a secondment to the council, the project will incorporate adapt their procedures for scour risk management and debris management. It will also investigate novel debris mitigation strategies to reduce flood risks and debris removal costs. The immediate impact for the council will be in significantly reduced costs for managing debris-related risks to bridge structures. The broader societal and economic impact will be via reduced disruption to the local transport network. The project will also engage with Highways England and other stakeholders in bridge management to adapt current guidance to better deal with debris risks to bridge structures.

Contact: p.kripakaran@exeter.ac.uk

Modelling of hydraulic fracturing using Extended Finite Element Method

PhD Projects: Davood Mahdavian & Yuxiao Wang

Gas produced from shale has revolutionised the oil and gas industry in the US and is a potential resource in many countries worldwide. Production is dependent on hydraulic fracture stimulation. Although hydraulic fracturing has been used for several decades, a thorough understanding of fracking processes is still lacking. To increase efficiency and meet political, environmental and public concerns it is essential to improve the current understanding of the geomechanical processes which occur during fracture stimulation which is the focus of this project. The study involves the development of a fully coupled hydro-mechanical model for hydro-fracturing of porous media with existing discontinues. Two fluids are considered: one representing the fracturing fluid and the other the host fluid. Flow through fracture and the rock matrix is considered. The fracture discontinuity in the mechanical model is captured using eXtended Finite Element Method (XFEM). The developed model will provide a valuable tool that can be used for (i) evaluating the hydraulic fracturing process and fracture propagation, (ii) predicting induced seismicity, and (iii) assessing potential leakage from the system and fate of contaminants in subsurface environment. Using the developed model, further understanding of the processes involved and their impacts can be achieved.

Scour and hydrodynamic forces on bridges

The EPSRC funded project titled “Risk assessment of masonry bridges under flood conditions: Hydrodynamic effects of debris blockage and scour” is aimed at characterising the science underpinning the flow around debris piled up in front of bridge piers and abutments. The project undertaken with extensive collaboration with industry (e.g. Network Rail, ADEPT, Devon County Council, Bridge Owners Forum, JBA Consulting) is leading to novel guidance for practitioners on managing the scour risks to bridge structures from debris accumulation.

For further information, visit our project blog.

Contact: p.kripakaran@exeter.ac.uk

Caption: Scour development for a bridge in Cumbria. (Image courtesy of Cumbria County Council).

Scour profiles and contour maps for a sharp-nosed bridge pier with a cylindrical debris.

Stabilization of soils with ash and fly ash based geopolymers

PhD Project: Canan Turan

In general, fine-grained soils have poor mechanical properties such as high swelling potential and low strength, which creates problems in construction projects. Many soil stabilization methods have been used to improve the properties of fine-grained soils. Fly ash is a waste material obtained from burning of coal in thermal power plants. Using of fly ash or fly ash with alkali activators has been shown to improve the mechanical properties of soils in an environmentally friendly and economical manner. The broad aim of this study is to understand the mechanical behaviour of clay soils stabilized with fly ash and fly ash based geo-polymers through a programme of laboratory experiments, chemical analysis, and numerical analysis.

Trixial testing system

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SEM images of class C fly ash, pure kaolinite and class F fly ash with 50 µm magnification factor

Three-dimensional finite element modelling of the groundwater flow and seawater intrusion in the Pingtung plain in Taiwan

PhD Project: Mahdieh Dibaj

In this study, a three-dimensional finite element model is developed to study the groundwater flow and seawater intrusion in Pingtung Plain, Taiwan. FEFLOW and Mike zero (Supported by DHI) are used in this research. This is a collaborative project with the National Taiwan University. The project is partially funded by the Royal Society.

Three-dimensional finite element modelling of knee structure

PhD Project: Kulchamai Thienkarochanakul

Knee osteoarthritis (OA) is a common medical condition that necessitates primary care for a significant proportion of adults over the age of 45. This causes functional limitations and decreases the quality of life. The most common symptoms of knee OA are persistent knee pain, morning stiffness and reduced function. In this project, a three-dimensional finite element model of a healthy knee was constructed. The geometric data were obtained by MRI scanning. Bones, articular cartilages, menisci, patella, patella tendon and all the relevant ligaments were included in the model in their bio-realistic structures. 3D gait measurements were analysed to define loading and boundary conditions. After validation, the 3D finite element model was used to analyse stresses and strains in the knee joint. The model provides a powerful tool to study the structural performance of the knee joint and the effects of OA on the stress and strain distributions in the knee.