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  • 1.
    Abdulhameed, Isam Mohammed
    et al.
    University of Anbar, College of Engineering, Upper Euphrates Basin Developing Centre, Ramadi, Iraq.
    Sulaiman, Sadeq Oleiwi
    University of Anbar, College of Engineering, Dams and Water Resources Department, Ramadi, Iraq.
    Ahmed Najm, Abu Baker
    University of Anbar, College of Engineering, Dams and Water Resources Department, Ramadi, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Optimising water resources management by Using Water Evaluation and Planning (WEAP) in the West of Iraq2022In: Journal of Water and Land Development, ISSN 1429-7426, no 53, p. 176-186Article in journal (Refereed)
    Abstract [en]

    Iraq has been suffering from decreasing Euphrates discharge due to the construction of dams within upstream countries and the use of surface irrigation systems. The country is facing a problem with meeting the increasing demand for water as a result of population growth and development in the industrial and agricultural sectors. Therefore, a simulation modelling was applied for western Iraq (Ramadi city as a case study) using the Water Evaluation and Planning System (WEAP) for the period 2018–2035. This research follows a four-step approach that involves: (i) evaluating the available water of the Euphrates River under declined water imports caused by the construction of dams in Turkey and Syria, (ii) assessing present and future water demands of the domestic, industrial, and agricultural sectors, (iii) improving water productivity (WP) by means of saving more water, (iv) estimating the economic returns under improved water use. The results showed that Iraq would face a serious problem in the coming years, represented by the limited storage of Haditha Dam, which is considered the strategic water storage site for the central and southern regions of Iraq. The study indicated the necessity of finding alternative sources of water supply by adopting new water management strategies to reduce the water deficit. 

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  • 2.
    Faraj, Dana Muhammad
    et al.
    Department of Water Resources Engineering, College of Engineering, University of Sulaimani, Sulaymaniyah 46002, Kurdistan Region, Iraq.
    Abdulrahman, Kawa Z.
    Department of Water Resources Engineering, College of Engineering, University of Sulaimani, Sulaymaniyah 46002, Kurdistan Region, Iraq.
    Al-Ansari, Nadhir A.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    The impact of the tropical water project on darbandikhan dam operation2022In: Journal of King Saud University - Engineering Sciences, ISSN 1018-3639Article in journal (Refereed)
    Abstract [en]

    Besides global warming and population growth, the Turkish and the Iranian water projects have negatively affected the water resources in Iraq. Recently, Iran has implemented its largest water project (The Tropical Water Project - TWP). This project aims to store the flowing water in the Sirwan and Zmkan rivers (i.e., tributaries of the Diyala River) to provide irrigation, domestic, and industrial water for areas inside and outside the Diyala River Basin. The Darbandikhan dam and Halabja water supply project are located on the Diyala River. In this study, the impact of the TWP on the operation of the Darbandikhan dam and Halabja water supply project was investigated. The monthly inflow data of the Darbandikhan dam from September 1991 to December 2017 were used to simulate the operation of the dam using the HEC-ResSim 3.1 package. Two scenarios have been adopted for the operation of the Darbandikhan dam. In the first scenario, the Darbandikhan dam operation was simulated without considering the effects of the TWP project.

    In contrast, in the second scenario, the full operation of the TWP project was considered. The results revealed that about 48.4% of the power generation capacity would be lost, and the water surface elevation in the reservoir would be affected significantly due to the TWP project. The water surface elevation would be at or below 443 m for long periods, which will affect the operation of the Halabja water supply project.

  • 3.
    Khullar, Subodh
    et al.
    Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee , Roorkee 247667, India.
    Singh, Krishna M.
    Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee , Roorkee 247667, India.
    Cervantes, Michel
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Gandhi, Bhupendra K.
    Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee , Roorkee 247667, India.
    Numerical Analysis of Water Jet Injection in the Draft Tube of a Francis Turbine at Part Load Operations2022In: Journal of Fluids Engineering, ISSN 0098-2202, E-ISSN 1528-901X, Vol. 144, no 11, article id 111201Article in journal (Refereed)
    Abstract [en]

    The off-design operation of Francis turbines results in the onset of flow instabilities. These instabilities lead to severe pressure pulsations, power swings, fatigue damage, and torque fluctuations in the turbine unit. Axial water jet injection in the draft tube is a relatively recent method proposed to reduce the detrimental effects of flow instabilities on turbine performance. However, its efficacy at different operating points needs to be ascertained before implementing in actual prototype turbines. This work reports the findings of numerical investigations performed with water injection at three different part-load conditions. These operating points represent distinct flow regimes in the draft tube. The effect of water injection on the velocity and pressure fields in the draft tube is investigated. The results indicate that the water jet strongly influences the turbine performance at part-loads involving a precessing vortex rope. However, little influence of water jet is observed at deep part-load operation. The interaction of the jet with the draft tube bend is also investigated. The results show that the amount of water jet needs to be cautiously controlled as higher water jet injection impacting the bend may deteriorate the performance. The influence of water jet injection on the pressure recovery, power output, and efficiency of the turbine unit is also reported.

  • 4.
    Li, Shicheng
    et al.
    Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Xie, Qiancheng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Yang, James
    Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Stockholm, Sweden; Vattenfall AB, R&D Hydraulic Laboratory, Älvkarleby, Sweden .
    Daily suspended sediment forecast by an integrated dynamic neural network2022In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 604, article id 127258Article in journal (Refereed)
    Abstract [en]

    Suspended sediment is of importance in river and dam engineering. While, due to its high nonlinearity and stochasticity, sediment prediction by conventional methods is a challenging task. Consequently, this paper establishes a new hybrid model for an improved forecast of suspended sediment concentration (SSC). It is a nonlinear autoregressive network with exogenous inputs (NARX) integrated with a data pre-processing framework (denoted as INARX). In this model, wavelet transformation (WT) is used for time series decomposition and multigene genetic programing (MGGP) for details scaling. The two incorporated modules improve time and frequency domain analysis, allowing the network to unveil the embedded characteristics and capture its non-stationarity. At a hydrological station on the upper reaches of the Yangtze River, the records of daily water stage, flow discharge and suspended sediment are collected and refer to a nine-year period during 2004-2012. The data are used to evaluate the models. Several wavelets are explored, showing that the Coif3 leads to the most accurate prediction. Compared to the sediment rating curve (SRC), the conventional MGGP, multilayer perceptron neural network (MLPNN) and NARX, the INARX demonstrates the best forecast performance. Its mean coefficient of determination (CD) increases by 7.7%-38.6% and the root mean squared error (RMSE) reduces by 15.1%-54.5%. The INARX with the Coif3 wavelet is further evaluated for flood events and multistep forecast. Under flood conditions, the model generates satisfactory results, with CD > 0.83 and 84.7% of the simulated data falling within the ±0.1 kg/m3 error. For the multistep forecast, at a one-week lead time, the network also yields predictions with acceptable accuracy (mean CD = 0.78). The model performance deteriorates if the lead time becomes larger. The established framework is robust and reliable for real-time and multistep SSC forecast and provides reference for time series modeling, e.g. streamflow, river temperature and salinity.

  • 5.
    Nordell, Bo
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water. Lillpite älvdals ekonomiska förening.
    Bergman, Gunnar
    Lillpite älvdals ekonomiska förening.
    Wiklund, Matz
    Lillpite älvdals ekonomiska förening.
    Development of the Lillpite River Valley after Dam Removal2018Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    The Lillpite River Valley stretches 45 km NV, from Piteå at the Gulf of Bothnia. The 619 km2 large catchment area comprises a dozen lakes. The average flow rate of the river is 6.24 m3/s. Lillpite Kraft AB, which owns the two power plants in the Lillpite River, has now applied for a demolition permit after 30 years of unprofitable operation. This demolition will take place in 2020, after which there are no obstacles to the fish's migration in the river. The Lillpite River was famous for its large salmon but also for its trout, grayling and lamprey. River crayfish and freshwater pearl mussel exist in the river, both upstream and downstream of the two dams, and in the brooks. There are even eel and pikeperch in the river, which also hosts beaver and otter. The Lillpite River Economic Association manages the compensation (~30M€ over 50 years) for the wind power intrusion in the area. This organisation is committed to make the river the fishing water it once was, as a driving force for the development of the river valley. At this seminar, we seek your help and advice based on knowledge and experience. How to determine the river status before and after dam removal? River erosion? Timeline after dam removal? Evaluation of ecology and biodiversity? How to improve conditions for fish, crustaceans and pearl mussel? How to meet sceptical locals? What should/could we do before the dam removal?

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  • 6.
    Patil, Aniket
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. SINTEF Narvik, Norway.
    Zhaka, Vasiola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sand, Björnar
    SINTEF Narvik, Norway.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Cwirzen, Andrzej
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Large-scale shear test of brash ice2022In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 249, article id 110935Article in journal (Refereed)
    Abstract [en]

    A large-scale shear apparatus has been originally developed and built to test the mechanical properties of coarse-grained material. It was used to evaluate the shear behaviour of brash ice. The brash ice blocks were collected at Luleå harbour in two separate measuring campaigns in March 2020 and March 2021. The shear cylinder was loaded with brash ice in Luleå port in two different locations for the two test campaigns, and the displacement-controlled shear tests were conducted. A vertical actuator was used to set a constant normal load and then a horizontal actuator was used to move the shear swing. In this setup, time, forces, and displacements were recorded at the forward and return stroke of the horizontal actuator. In total 6 shear cycles on two brash ice samples with axial stress of 4.8 kPa, 2 kPa and 1 kPa were performed. The test data was analysed to determine the relationship between shear stress and shear strain. The macro-porosity and confining axial force were found to be the most influential factors in determining the strength and deformation of the brash ice. Furthermore, an attempt has been made to estimate a few parameters of a material model known as the Continuous Surface Cap Model.

    The full text will be freely available from 2031-10-01 11:18
  • 7.
    Pitorac, Livia
    et al.
    Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, S. P. Andersens veg 5, Trondheim 7031, Norway.
    Vereide, Kaspar
    Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, S. P. Andersens veg 5, Trondheim 7031, Norway; Sira-Kvina Hydropower Company, Stronda 12, Tonstad 4440, Norway.
    Lia, Leif
    Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, S. P. Andersens veg 5, Trondheim 7031, Norway.
    Cervantes, Michel
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Hydraulic Scale Modeling of Mass Oscillations in a Pumped Storage Plant with Multiple Surge Tanks2022In: Journal of Hydraulic Engineering, ISSN 0733-9429, E-ISSN 1943-7900, Vol. 148, no 9, article id 05022002Article in journal (Refereed)
    Abstract [en]

    As power systems include more intermittent renewable energy sources, energy storage solutions are needed to support them. Pumped hydro is a reliable alternative for long-term energy storage. A solution for bringing more pumped hydro into the power system is to upgrade existing hydropower plants into pumped hydro. To investigate this possibility, a case study with a complex tunnel system and multiple surge tanks along both the headrace and the tailrace tunnels is selected. A hydraulic scale model and validation methods were developed. The challenges in developing and validating complex models involving multiple surge tanks, throttles, head loss, and limited prototype information are detailed. 

  • 8.
    Xie, Qiancheng
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Yang, James
    Vattenfall AB, R&D Hydraulic Laboratory, 81426 Älvkarleby, Sweden; Department of Civil and Architectural Engineering, Royal Institute of Technology, 10044 Stockholm, Sweden.
    Lundström, Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Chen, Jieren
    College of Water Conservancy and Hydropower Engineering, Hohai University, 210098 Nanjing, China.
    Hybrid Modeling for Solutions of Sediment Deposition in a Low-Land Reservoir with Multigate Sluice Structure2022In: Applied Sciences, E-ISSN 2076-3417, Vol. 12, no 18, article id 9144Article in journal (Refereed)
    Abstract [en]

    At the multigate sluice structure on a fluvial river, undesired sediment deposition affects the normal operation of the reservoir in question. Physical and numerical models are hybridized to help explore flow and sedimentation patterns. Field and laboratory investigations show that the deposition is attributable to the formation of large recirculation zones at low and medium discharges. As a potential countermeasure, an array of guide vanes is recommended to cope with the concern. Their attack angle with the flow is a dominant parameter that needs to be evaluated. Tests in the fixed-bed model demonstrate that the vanes bend the reservoir flow towards the sluice and suppress the circulation zones along both banks. The favorable range of attack angle is 15–20°. With the examination of sedimentation of both bed and suspended loads, the numerical modeling indicates that the sediment-removal efficiency increases with an increase in attack angle. By weighing the flushing efficiency and the risk of local scouring at the vanes, the 15° vane layout is recommended. This study is expected to provide a reference for guide-vane design in similar situations.

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  • 9.
    Xue, Delai
    et al.
    School of Marine Engineering, Jimei University, Xiamen 361021, PR China.
    Wu, Defeng
    School of Marine Engineering, Jimei University, Xiamen 361021, PR China; Fujian Provincial Key Laboratory of Naval Architecture and Ocean Engineering, Xiamen 361021, PR China.
    Yamashita, Andre S.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Li, Zhixiong
    Donghai Laboratory, Zhoushan 316021, China; Faculty of Mechanical Engineering, Opole University of Technology, Opole 45758, Poland.
    Proximal policy optimization with reciprocal velocity obstacle based collision avoidance path planning for multi-unmanned surface vehicles2023In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 273, article id 114005Article in journal (Refereed)
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