International Journal of Marine Energy最新文献

{"title":"Performance characterization of a cross-flow hydrokinetic turbine in sheared inflow","authors":"Dominic Forbush ,&nbsp;Brian Polagye ,&nbsp;Jim Thomson ,&nbsp;Levi Kilcher ,&nbsp;James Donegan ,&nbsp;Jarlath McEntee","doi":"10.1016/j.ijome.2016.06.001","DOIUrl":"https://doi.org/10.1016/j.ijome.2016.06.001","url":null,"abstract":"<div><p><span>A method for constructing a non-dimensional performance curve for a cross-flow hydrokinetic turbine in sheared flow is developed for a natural river site. The river </span>flow characteristics are quasi-steady, with negligible vertical shear, persistent lateral shear, and synoptic changes dominated by long time scales (days to weeks). Performance curves developed from inflow velocities measured at individual points (randomly sampled) yield inconclusive turbine performance characteristics because of the spatial variation in mean flow. Performance curves using temporally- and spatially-averaged inflow velocities are more conclusive. The implications of sheared inflow are considered in terms of resource assessment and turbine control.</p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 150-161"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91726027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A sensitivity analysis on tidal stream turbine loads caused by operational, geometric design and inflow parameters","authors":"T.M. Nevalainen,&nbsp;C.M. Johnstone,&nbsp;A.D. Grant","doi":"10.1016/j.ijome.2016.05.005","DOIUrl":"10.1016/j.ijome.2016.05.005","url":null,"abstract":"<div><p><span>This paper presents a sensitivity analysis on a numerical tidal stream turbine model where a multitude of input parameters’ effect on the load output were determined. The statistical procedure used, known as the Morris method, provided insight into the interactions between the parameters as well as showing their comparative influence on the turbine loading. The investigation covered parameters from the operational, geometric design and inflow variable domains where the </span>rotor radius<span>, current shear, blade root pitch, surface velocity<span><span> and wave height were identified as most influential. The blade pitch was regarded as a surprisingly prominent influence on the loads. The turbine’s operating depth and the blade geometry were also found to be of limited influence in the ranges investigated. In terms of load transmission into the internal components of a turbine’s drive train, the rotor out-of-plane bending moment, or eccentric bending moment, was found to be a considerable contribution to the off-axis loads on the shaft. Therefore, special attention was paid to the input parameters’ relationship to the </span>eccentric load component by performing a detailed study on the load variations caused by the identified primary input parameters. It is concluded that performing a sensitivity analysis on a tidal stream turbine in a specific operating climate can yield insight to the expected load range and that the eccentric loading transmitted to the shaft is significant for most input cases.</span></span></p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 51-64"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.05.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74449913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aims & Scope + Editorial Board (IFC)","authors":"","doi":"10.1016/S2214-1669(16)30070-4","DOIUrl":"https://doi.org/10.1016/S2214-1669(16)30070-4","url":null,"abstract":"","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Page IFC"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S2214-1669(16)30070-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137168018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing nekton distributions at two tidal energy sites suggests potential for generic environmental monitoring","authors":"Lauren Wiesebron, J. Horne, B. Scott, B. Williamson","doi":"10.1016/J.IJOME.2016.07.004","DOIUrl":"https://doi.org/10.1016/J.IJOME.2016.07.004","url":null,"abstract":"","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"22 1","pages":"235-249"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73764726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling, simulation and testing of a submerged oscillating water column","authors":"J. Fairhurst, J. V. Niekerk","doi":"10.1016/J.IJOME.2016.07.005","DOIUrl":"https://doi.org/10.1016/J.IJOME.2016.07.005","url":null,"abstract":"","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"2014 1","pages":"181-195"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82738804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accelerated reliability testing of articulated cable bend restrictor for offshore wind applications","authors":"Philipp R. Thies ,&nbsp;Lars Johanning ,&nbsp;Imran Bashir ,&nbsp;Ton Tuk ,&nbsp;Marloes Tuk ,&nbsp;Marco Marta ,&nbsp;Sven Müller-Schütze","doi":"10.1016/j.ijome.2016.05.006","DOIUrl":"10.1016/j.ijome.2016.05.006","url":null,"abstract":"<div><p>Power cable failures for offshore marine energy applications are a growing concern since experience from offshore wind has shown repeated failures of inter-array and export cables. These failures may be mitigated by dedicated cable protection systems, such as bend restrictors. This paper presents the rationale and the results for accelerated reliability tests of an articulated bend restrictor. The tests are a collaborative effort between the University of Exeter, CPNL Engineering and NSW, supported by the EU MARINET programme.</p><p>The tests have been carried out at full-scale and exposed the static submarine power cable, fitted with an articulated pipe bend restrictor, to mechanical load regimes exceeding the allowable design loads in order to provoke accelerated wear and component failures. The tested load cases combined cyclic bending motions with oscillating tensile forces. A range of acceleration factors have been applied in respect to the 1:50<!--> <!-->years load case, subjecting each of the three restrictor samples to 25,000 bending cycles (50,000 tensile cycles). The static power cable was also loaded beyond its intended use, testing the worst case scenario of repeated dynamic loading, purposely inflicting failure modes for investigation. Throughout the test the static submarine power cable sustained over 77,000 bending cycles.</p><p>The test demonstrated the integrity of the cable protection system with quantified wear rates obtained through 3D scanning of the individual shells. The static power cable also maintained its integrity throughout the accelerated test regime. None of the failure modes, mainly fatigue cracks and fretting of individual wires, identified by cable dissection would have caused a direct loss of service. The observed failure modes could also be predicted through numerical load analysis, giving confidence in the utilised mechanical modelling and cross-sectional analysis for dynamic applications.</p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 65-82"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.05.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86191677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical assessments of ocean energy extraction from western boundary currents using a quasi-geostrophic ocean circulation model","authors":"Omer San","doi":"10.1016/j.ijome.2016.05.002","DOIUrl":"10.1016/j.ijome.2016.05.002","url":null,"abstract":"<div><p>A single-layer, quasi-geostrophic (QG), large-scale ocean circulation model is developed in this paper to study available ocean current energy potentials harnessed by using the ocean current turbines. Power extraction is modeled by adding a parameterized Rayleigh friction term in the barotropic vorticity equation. Numerical assessments are performed by simulating a set of mid-latitude ocean basins in the beta plane, which are standard prototypes of more realistic ocean dynamics considering inter-decadal variability in turbulent equilibrium. The third-order Runge–Kutta scheme for the temporal discretization and the second-order conservative Arakawa scheme for the spatial discretization are utilized to perform Munk scale resolving high-resolution computations. A sensitivity analysis with respect to the turbine parameters is performed for various physical conditions. Results show that the proposed model captures the quasi-stationary ocean dynamics and provides the four-gyre circulation patterns in time mean. After an initial spin-up process, the proposed model reaches a statistically steady state at an average maximum speed between 1.5<!--> <!-->m/s and 2.5<!--> <!-->m/s, which is close to the observed maximum zonal velocities in the western boundary currents. The probability density function of the available power over a long time period is computed for a wide range of parameters. Numerical results shows that 10<!--> <!-->GW mean power can be extracted from the turbines distributed over a length scale of 100<!--> <!-->km along the western boundaries. However, it is demonstrated that bigger turbine areas would alter the flow patterns and energetics due to excessive dissipation. An increase in the turbine area results in an increase in the available power ranging from 8 to 22<!--> <!-->GW depending on the values of turbine modeling parameters. This first step in the numerical assessment of the proposed QG model shows that the present framework could represent a viable tool for evaluating energy potentials in a highly turbulent flow regime.</p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 12-29"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.05.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87520462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal Wells turbine speeds at different wave conditions","authors":"Paresh Halder,&nbsp;Abdus Samad","doi":"10.1016/j.ijome.2016.05.008","DOIUrl":"https://doi.org/10.1016/j.ijome.2016.05.008","url":null,"abstract":"<div><p>The present study aims to predict and optimize the operating range of a Wells turbine that essentially works on the principle of bidirectional flow in an ocean renewable energy system. The turbine operates in a narrow range because of variability in waves, machine geometry and low incidence angle that lead to stumpy performance of the turbine. Hence, a relationship between the fluid velocity and the turbine speed has been established to design a turbine with higher performance. The two different cases, with and without a tip groove, were considered to predict the optimal turbine speed for the different flow velocities. A multiple-surrogate based approach has been used to find correlation between the turbine speed and the air velocity, and a Reynolds-averaged Navier–Stokes equation solver evaluated the turbine performance parameters. Furthermore, several combinations of the variables (flow velocity and turbine speed) along with an objective function (efficiency) were evaluated by the solver. The grooved-casing design performs better than that of the without grooved-casing, and the mid-chord of the blade enhances the exchange of momentum among different directions and suppresses the unsteadiness.</p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 133-149"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.05.008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91761055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimising power take-off of an oscillating wave surge converter using high fidelity numerical simulations","authors":"Pál Schmitt ,&nbsp;Henrik Asmuth ,&nbsp;Björn Elsäßer","doi":"10.1016/j.ijome.2016.07.006","DOIUrl":"10.1016/j.ijome.2016.07.006","url":null,"abstract":"<div><p>Oscillating wave surge converters are a promising technology to harvest ocean wave energy in the near shore region. Although research has been going on for many years, the characteristics of the wave action on the structure and especially the phase relation between the driving force and wave quantities like velocity or surface elevation have not been investigated in detail. The main reason for this is the lack of suitable methods. Experimental investigations using tank tests do not give direct access to overall hydrodynamic loads, only damping torque of a power take off system can be measured directly. Non-linear computational fluid dynamics methods have only recently been applied in the research of this type of devices. This paper presents a new metric named wave torque, which is the total hydrodynamic torque minus the still water pitch stiffness at any given angle of rotation. Changes in characteristics of that metric over a wave cycle and for different power take off settings are investigated using computational fluid dynamics methods. Firstly, it is shown that linearised methods cannot predict optimum damping in typical operating states of OWSCs. We then present phase relationships between main kinetic parameters for different damping levels. Although the flap seems to operate close to resonance, as predicted by linear theory, no obvious condition defining optimum damping is found.</p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 196-208"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.07.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83574689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing nekton distributions at two tidal energy sites suggests potential for generic environmental monitoring","authors":"Lauren E. Wiesebron ,&nbsp;John K. Horne ,&nbsp;Beth E. Scott ,&nbsp;Benjamin J. Williamson","doi":"10.1016/j.ijome.2016.07.004","DOIUrl":"https://doi.org/10.1016/j.ijome.2016.07.004","url":null,"abstract":"<div><p>Tidal energy is a renewable resource that can contribute towards meeting growing energy demands, but uncertainties remain about environmental impacts of device installation and operation. Environmental monitoring programs are used to detect and evaluate impacts caused by anthropogenic disturbances and are a mandatory requirement of project operating licenses in the United States. In the United Kingdom, consent conditions require monitoring of any adverse impacts on species of concern. While tidal turbine sites share similar physical characteristics (e.g. strong tidal flows), similarities in their biological characteristics have not been examined. To characterize the generality of biological attributes at tidal energy sites, metrics derived from acoustic backscatter describing temporal and spatial distributions of fish and macrozooplankton at Admiralty Inlet, Washington State and the Fall of Warness, Scotland were compared using <em>t</em>-tests, <em>F</em>-tests, linear regressions, spectral analysis, and extreme value analysis (EVA). EVA was used to characterize metric values that are rare but potentially associated with biological impacts, defined as relevant change as a consequence of human activity. Pelagic nekton densities were similar at both sites, as evidenced by no statistically significant difference in densities, and similar daily density patterns of pelagic nekton between sites. Biological characteristics were similar, suggesting that generic biological monitoring programs could be implemented at these two sites, which would streamline permitting, facilitate site comparison, and enable environmental impact detection associated with tidal energy deployment.</p></div>","PeriodicalId":100705,"journal":{"name":"International Journal of Marine Energy","volume":"16 ","pages":"Pages 235-249"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ijome.2016.07.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91726030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}