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Rodolfo Espina-Valdés
Hydraulic R&D Group, EP Mieres, University of Oviedo, Gonzalo Gutiérrez Quirós, 33600 Mieres, Spain

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Journal article
Published: 08 May 2021 in Sustainability
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Smart cities have a significant impact on the future of renewable energies as terms such as sustainability and energy saving steadily become more common. In this regard, both wind and hydrokinetic compact-size turbines can play important roles in urban communities by providing energy to nearby consumption points in an environmentally suitable manner. To evaluate the operation of a Darrieus turbine rotor as a wind or hydro microgenerator, a series of wind tunnel and water current flume tests were performed. Power and characteristic curves were obtained for all test conditions. In the wind tests, all curves seemed to be identical, which means that the turbine rotor works properly under open-field conditions. Two blockage correction equations were applied to the water channel tests that were performed under blockage values ranging from 0.2 to 0.35 to estimate the operational behavior in open water. Finally, it has been demonstrated that, with the condition of maintaining the Reynolds number between experiments in the wind tunnel and water flume, the turbine wind characteristics represents the its operation in open-water conditions.

ACS Style

Ahmed Gharib-Yosry; Eduardo Blanco-Marigorta; Aitor Fernández-Jiménez; Rodolfo Espina-Valdés; Eduardo Álvarez-Álvarez. Wind–Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems. Sustainability 2021, 13, 5256 .

AMA Style

Ahmed Gharib-Yosry, Eduardo Blanco-Marigorta, Aitor Fernández-Jiménez, Rodolfo Espina-Valdés, Eduardo Álvarez-Álvarez. Wind–Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems. Sustainability. 2021; 13 (9):5256.

Chicago/Turabian Style

Ahmed Gharib-Yosry; Eduardo Blanco-Marigorta; Aitor Fernández-Jiménez; Rodolfo Espina-Valdés; Eduardo Álvarez-Álvarez. 2021. "Wind–Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems." Sustainability 13, no. 9: 5256.

Preprint
Published: 31 March 2021
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Smart cities will have a strong impact on the future of renewable energies as terms like sustainability and energy saving will be more common. In this sense, both of wind and hydrokinetic compact-size turbines, can play an important role in urban communities by providing energy to nearby consumption points in an environmentally suitable way. This work presents the experimental evaluation for a vertical-axis turbine Darrieus type, operating in an open-field wind tunnel and a confined water channel. Power and characteristic curves have been obtained for all test conditions, also the effect of turbine blockage has been evaluated under blockage values ranging from 6.8% to 35%. The peak power coefficient for the confined flow condition reached a value of 0.31 which is 1.5 times higher than the peak one for the experimental open field condition at the same Reynolds number and a blockage of 20%. Finally, two blockage correction equations have been applied to the water channel tests, which gave values quite similar to the results obtained from the wind tunnel.

ACS Style

Ahmed Gharib-Yosry; Eduardo Blanco-Marigorta; Aitor Fernández-Jiménez; Rodolfo Espina-Valdés; Eduardo Álvarez-Álvarez. Wind-Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems. 2021, 1 .

AMA Style

Ahmed Gharib-Yosry, Eduardo Blanco-Marigorta, Aitor Fernández-Jiménez, Rodolfo Espina-Valdés, Eduardo Álvarez-Álvarez. Wind-Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems. . 2021; ():1.

Chicago/Turabian Style

Ahmed Gharib-Yosry; Eduardo Blanco-Marigorta; Aitor Fernández-Jiménez; Rodolfo Espina-Valdés; Eduardo Álvarez-Álvarez. 2021. "Wind-Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems." , no. : 1.

Article
Published: 31 May 2020 in Water Resources Management
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As water is a scarce natural resource, one of the most crucial aspects influencing its management is the measurement of user consumptions. There are many studies which set out to analyze issues related to water meter accuracy from either a technical or economical point of view. This investigation proposes an approach that integrates both technical and economic studies to advise in the error evaluation and the units renewal decisions. The technical study includes a methodology for measuring the error produced at different flow rates and an analysis of the results obtained. In the economic study three methods – linked to different management strategies – have been outlined to make an adequate appraisal of the water meter replacement time. The procedure was applied to the water meter park of a medium-sized Spanish city. Results indicate that both measured volume and age contribute to the error evolution, and that there was no noticeable influence regarding either the transmission type or the brand. In the economic study, specific results related to the water replacement were obtained, and a sensibility analysis revealed the influence of the price of water, water meter cost and the cost of capital.

ACS Style

Víctor Manuel Fernández Pacheco; Rodolfo Espina Valdés; Enrique Bonet Gil; Antonio Navarro Manso; Eduardo Álvarez Álvarez. Techno-Economic Analysis of Residential Water Meters: A Practical Example. Water Resources Management 2020, 34, 2471 -2484.

AMA Style

Víctor Manuel Fernández Pacheco, Rodolfo Espina Valdés, Enrique Bonet Gil, Antonio Navarro Manso, Eduardo Álvarez Álvarez. Techno-Economic Analysis of Residential Water Meters: A Practical Example. Water Resources Management. 2020; 34 (8):2471-2484.

Chicago/Turabian Style

Víctor Manuel Fernández Pacheco; Rodolfo Espina Valdés; Enrique Bonet Gil; Antonio Navarro Manso; Eduardo Álvarez Álvarez. 2020. "Techno-Economic Analysis of Residential Water Meters: A Practical Example." Water Resources Management 34, no. 8: 2471-2484.

Journal article
Published: 22 April 2020 in Energy Conversion and Management
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Obtaining electrical energy from water streams with velocities below one meter per second using hydrokinetic turbines presents an important challenge as it is significantly lower than the range of operations (higher than two meters per second) offered by units currently commercialized. This research goes one step further than the state-of-the-art studies regarding the degree to which energy extraction is influenced by the water flow blockage caused by turbines in water flows; presenting that blockage as a key factor in the procurement of electrical energy using hydrokinetic micro turbines from low-velocity flowing water. Primarily, it describes the design and characterization of a small vertical-axis cross-flow hydrokinetic turbine whose dimensions maximize the blockage of the water circulating in a channel at very low velocity. For the turbine characterization, a model has been tested experimentally in a water tunnel with different flow rates and complemented by simulations under the same conditions using an adjusted computational fluid dynamics model. The experimental tests contemplate the measuring of the turbine’s electrical power, hydraulic coefficient and rotational speeds. The simulations of the numerical model facilitate the procurement of the corresponding water pressure and velocity fields. Further analysis has allowed for a closer examination of the different type of forces exerted on the faces of the blades as well as their position. Upon even closer inspection there appear to be a variety of possible scenarios contingent on the turbine load.

ACS Style

Rodolfo Espina-Valdés; Aitor Fernández-Jiménez; Joaquín Fernández Francos; Eduardo Blanco Marigorta; Eduardo Álvarez-Álvarez. Small cross-flow turbine:Design and testing in high blockage conditions. Energy Conversion and Management 2020, 213, 112863 .

AMA Style

Rodolfo Espina-Valdés, Aitor Fernández-Jiménez, Joaquín Fernández Francos, Eduardo Blanco Marigorta, Eduardo Álvarez-Álvarez. Small cross-flow turbine:Design and testing in high blockage conditions. Energy Conversion and Management. 2020; 213 ():112863.

Chicago/Turabian Style

Rodolfo Espina-Valdés; Aitor Fernández-Jiménez; Joaquín Fernández Francos; Eduardo Blanco Marigorta; Eduardo Álvarez-Álvarez. 2020. "Small cross-flow turbine:Design and testing in high blockage conditions." Energy Conversion and Management 213, no. : 112863.

Original paper
Published: 31 May 2019 in Clean Technologies and Environmental Policy
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Tidal energy is considered as an energy resource of maximum interest in both technical and research fields due to its largely unexploited energy potential. The use of hydrokinetic microturbines is now an attractive option with reduced environmental impact. The first step to evaluate the feasibility of a hydrokinetic microturbines installation is to perform a study of the velocity field characteristics and therefore the energy potential available. Up to now, different numerical models, of one, two and three spatial dimensions have been applied to evaluate the tidal potential in large areas. Due to the high computational resources needed, they include simplifications, like avoiding a precise study of the velocity in the vertical dimension, resulting in incomplete estimations of the available kinetic energy. To complete these estimations, the research presented sets out a methodology to evaluate the current effects, velocity profiles and the energy potential derived from tide movements in an estuary or port by solving the full Navier–Stokes equations. It also considers the water–air interface in the numerical scheme. The methodology is based, firstly, on the definition of a three-dimensional geometrical model of the geographical area of study, and then, the complete model is meshed with finite volumes, where the full three-dimensional Unsteady Navier–Stokes equations are solved. The methodology was applied and validated with a three-dimensional water–air numerical model of the port of Avilés (Spain). In conclusion, water surface elevations, averaged speed cycles, velocity profiles as a function of depth and tidal power and energy data have been obtained without the usual simplifications, which will mean an evaluation more accurate when assessing the implementation of a power generation system.

ACS Style

Rodolfo Espina-Valdés; Eduardo Álvarez Álvarez; Julio García-Maribona; Antonio José Gutiérrez Trashorras; Juan Manuel Gonzalez-Caballin. Tidal current energy potential assessment in the Avilés Port using a three-dimensional CFD method. Clean Technologies and Environmental Policy 2019, 21, 1367 -1380.

AMA Style

Rodolfo Espina-Valdés, Eduardo Álvarez Álvarez, Julio García-Maribona, Antonio José Gutiérrez Trashorras, Juan Manuel Gonzalez-Caballin. Tidal current energy potential assessment in the Avilés Port using a three-dimensional CFD method. Clean Technologies and Environmental Policy. 2019; 21 (6):1367-1380.

Chicago/Turabian Style

Rodolfo Espina-Valdés; Eduardo Álvarez Álvarez; Julio García-Maribona; Antonio José Gutiérrez Trashorras; Juan Manuel Gonzalez-Caballin. 2019. "Tidal current energy potential assessment in the Avilés Port using a three-dimensional CFD method." Clean Technologies and Environmental Policy 21, no. 6: 1367-1380.

Review
Published: 02 May 2019 in Energies
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Tides can be a vast and predictable source of renewable energy. Due to the solar and lunar influx on our planet, they move large amounts of water periodically, and this energy can be harnessed using devices designed and positioned adequately, such as current turbines. However, the relation between the energy obtained with actual devices and the economic and environmental cost of their installation limits the practical application of these solutions. In order to optimize the design of this technology and achieve its successful installation and use, a detailed knowledge about the energy potential of tides at the specific location is necessary. This calculation is not easy and requires the use of specialized software tools. Currently, there is no specific software to evaluate the tidal currents energy potential, but there are more than a few codes able to calculate the hydraulic flow in rivers, estuaries and coastal regions. These programs are usually used for the calculation of pollutant dispersion and floods, but they can be adapted with more or less success. This paper reviews the available 1D, 2D, and 3D software tools with the aim of analyzing their functionality and their validity to evaluate the energy potential of tidal currents.

ACS Style

María José Suárez-López; Rodolfo Espina-Valdés; Víctor Manuel Fernández Pacheco; Antonio Navarro Manso; Eduardo Blanco-Marigorta; Eduardo Alvarez Alvarez. A Review of Software Tools to Study the Energetic Potential of Tidal Currents. Energies 2019, 12, 1673 .

AMA Style

María José Suárez-López, Rodolfo Espina-Valdés, Víctor Manuel Fernández Pacheco, Antonio Navarro Manso, Eduardo Blanco-Marigorta, Eduardo Alvarez Alvarez. A Review of Software Tools to Study the Energetic Potential of Tidal Currents. Energies. 2019; 12 (9):1673.

Chicago/Turabian Style

María José Suárez-López; Rodolfo Espina-Valdés; Víctor Manuel Fernández Pacheco; Antonio Navarro Manso; Eduardo Blanco-Marigorta; Eduardo Alvarez Alvarez. 2019. "A Review of Software Tools to Study the Energetic Potential of Tidal Currents." Energies 12, no. 9: 1673.

Journal article
Published: 23 May 2018 in Open Engineering
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Obtaining energy from tide currents in onshore locations is of great interest due to the proximity to the points of consumption. This opens the door to the feasibility of new installations based on hydrokinetic microturbines even in zones of moderate speed. In this context, the accuracy of energy predictions based on hydrodynamic models is of paramount importance. This research presents a high precision methodology based on a multidimensional hydrodynamic model that is used to study the energetic potential in estuaries. Moreover, it is able to estimate the flow variations caused by microturbine installations. The paper also shows the results obtained from the application of the methodology in a study of the Nalón river mouth (Asturias, Spain).

ACS Style

Nicolás Badano; Rodolfo Espina Valdés; Eduardo Álvarez Álvarez. Tidal current energy potential of Nalón river estuary assessment using a high precision flow model. Open Engineering 2018, 8, 118 -123.

AMA Style

Nicolás Badano, Rodolfo Espina Valdés, Eduardo Álvarez Álvarez. Tidal current energy potential of Nalón river estuary assessment using a high precision flow model. Open Engineering. 2018; 8 (1):118-123.

Chicago/Turabian Style

Nicolás Badano; Rodolfo Espina Valdés; Eduardo Álvarez Álvarez. 2018. "Tidal current energy potential of Nalón river estuary assessment using a high precision flow model." Open Engineering 8, no. 1: 118-123.