Pub Date : 2020-05-18DOI: 10.1080/09377255.2020.1763591
Ali Ghasemi Koohi Kheili, A. Aghakouchak
ABSTRACT Fixed offshore platforms are always subjected to dynamic loading. A potentially economical method to improve the dynamic behaviour of these platforms is using passive control devices. In this paper, the application of tuned liquid damper, TLD, in controlling the response of a fixed offshore platform located in the Persian Gulf against earthquake and wave loading was studied. Analysis of a 3D model of the structure equipped with TLDs was carried out using the finite element method, and the efficiency of TLDs was investigated. Also, the equivalent models of TLDs were constructed based on the lumped mass method, and linear wave theory and the results were compared to finite element modelling of TLD. Results showed good agreement between the finite element model of TLD and equivalent lumped mass model. Results also indicated that adding TLDs can mitigate jacket deck vibrations and their efficiency increases as wave height or ground motion increase.
{"title":"Feasibility of reducing dynamic response of a fixed offshore platform using tuned liquid dampers","authors":"Ali Ghasemi Koohi Kheili, A. Aghakouchak","doi":"10.1080/09377255.2020.1763591","DOIUrl":"https://doi.org/10.1080/09377255.2020.1763591","url":null,"abstract":"ABSTRACT Fixed offshore platforms are always subjected to dynamic loading. A potentially economical method to improve the dynamic behaviour of these platforms is using passive control devices. In this paper, the application of tuned liquid damper, TLD, in controlling the response of a fixed offshore platform located in the Persian Gulf against earthquake and wave loading was studied. Analysis of a 3D model of the structure equipped with TLDs was carried out using the finite element method, and the efficiency of TLDs was investigated. Also, the equivalent models of TLDs were constructed based on the lumped mass method, and linear wave theory and the results were compared to finite element modelling of TLD. Results showed good agreement between the finite element model of TLD and equivalent lumped mass model. Results also indicated that adding TLDs can mitigate jacket deck vibrations and their efficiency increases as wave height or ground motion increase.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1763591","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45822710","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}
Pub Date : 2020-05-13DOI: 10.1080/09377255.2020.1761618
H. Söding
ABSTRACT Accurate predictions of ship motions and loads in a steep seaway require to include contributions depending non-linearly on wave amplitude. CFD methods do that routinely, but they require very high computing effort. Previous potential methods neglect either all or at least some nonlinear effects. The present method includes all substantial nonlinear effects amenable to potential flow. Using approximations for effects of flow separation at the aft end of hull and rudder, an accuracy comparable to that of good model experiments and CFD calculations is attained. That is demonstrated for motions and loads in cross sections of a containership sailing in head and quartering waves of large amplitude. Compared are results of model experiments, CFD calculations, a linear and the new nonlinear potential flow method. Another comparison is made for motions and added resistance of a second containership in head waves, where, apparently, an exceptional accuracy of experiments and calculations has been attained. A number of new ideas which were necessary to obtain a robust and accurate, fully nonlinear procedure are described. In typical cases, the method may take only one or a few percent of the computing effort of a comparable CFD computation.
{"title":"Fast accurate seakeeping predictions","authors":"H. Söding","doi":"10.1080/09377255.2020.1761618","DOIUrl":"https://doi.org/10.1080/09377255.2020.1761618","url":null,"abstract":"ABSTRACT Accurate predictions of ship motions and loads in a steep seaway require to include contributions depending non-linearly on wave amplitude. CFD methods do that routinely, but they require very high computing effort. Previous potential methods neglect either all or at least some nonlinear effects. The present method includes all substantial nonlinear effects amenable to potential flow. Using approximations for effects of flow separation at the aft end of hull and rudder, an accuracy comparable to that of good model experiments and CFD calculations is attained. That is demonstrated for motions and loads in cross sections of a containership sailing in head and quartering waves of large amplitude. Compared are results of model experiments, CFD calculations, a linear and the new nonlinear potential flow method. Another comparison is made for motions and added resistance of a second containership in head waves, where, apparently, an exceptional accuracy of experiments and calculations has been attained. A number of new ideas which were necessary to obtain a robust and accurate, fully nonlinear procedure are described. In typical cases, the method may take only one or a few percent of the computing effort of a comparable CFD computation.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1761618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44256877","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}
Pub Date : 2020-05-03DOI: 10.1080/09377255.2019.1655260
Aleksandar-Saša Milaković, Fang Li, R. U. F. von Bock und Polach, S. Ehlers
ABSTRACT Several definitions of equivalent ice thickness for simplification of complex ice cover are found in the literature. However, their systematic analysis is currently absent. Therefore, this paper reviews different definitions and validates them against a high-fidelity ice transit simulator, determining the most accurate one, with an average error of 16% for one analysed ship, and 10.5% for the other. Furthermore, capability of equivalent ice thickness to predict ship besetting in ice is tested, accurately predicting this event in 88% of the cases. Moreover, sensitivity analysis to the parameters not included in the traditional definitions is conducted, and it is found that only the thickness of ridge consolidated layer has significant impact. Finally, traditional concept based on equivalent ice volume is extended, and a concept of equivalent-performance ice thickness is developed, outperforming the traditional approach by reducing the average error to 4.6% for one ship, and to 3.2% for the other.
{"title":"Equivalent ice thickness in ship ice transit simulations: overview of existing definitions and proposition of an improved one","authors":"Aleksandar-Saša Milaković, Fang Li, R. U. F. von Bock und Polach, S. Ehlers","doi":"10.1080/09377255.2019.1655260","DOIUrl":"https://doi.org/10.1080/09377255.2019.1655260","url":null,"abstract":"ABSTRACT Several definitions of equivalent ice thickness for simplification of complex ice cover are found in the literature. However, their systematic analysis is currently absent. Therefore, this paper reviews different definitions and validates them against a high-fidelity ice transit simulator, determining the most accurate one, with an average error of 16% for one analysed ship, and 10.5% for the other. Furthermore, capability of equivalent ice thickness to predict ship besetting in ice is tested, accurately predicting this event in 88% of the cases. Moreover, sensitivity analysis to the parameters not included in the traditional definitions is conducted, and it is found that only the thickness of ridge consolidated layer has significant impact. Finally, traditional concept based on equivalent ice volume is extended, and a concept of equivalent-performance ice thickness is developed, outperforming the traditional approach by reducing the average error to 4.6% for one ship, and to 3.2% for the other.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2019.1655260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43110423","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}
Pub Date : 2020-05-03DOI: 10.1080/09377255.2019.1602976
Yanxin Feng, O. E. Moctar, T. Schellin
ABSTRACT The aim of this study was to reduce the total resistance of a multi-purpose wind offshore supply vessel by optimising its hull. Resistance was computed using a potential flow boundary element method and a Reynolds-averaged Navier–Stokes equations solver. Optimised hull forms were obtained for the ship advancing at different ship speeds under calm water conditions, employing the two multi-objective optimisation algorithms, Non-dominated Sorting Genetic Algorithm II (NSGA-II) and Multi-Objective Simulated Annealing (MOSA). Using NSGA-II yielded slightly larger reductions of total resistances than MOSA. The greatest reductions were achieved at ship speeds between 11 and 14knots. At these speeds, a thinner and longer bulbous bow reduced resistance. At speeds greater than 15knots, a bloated bulbous bow was more helpful to reduce resistance.
{"title":"Hydrodynamic optimisation of a multi-purpose wind offshore supply vessel","authors":"Yanxin Feng, O. E. Moctar, T. Schellin","doi":"10.1080/09377255.2019.1602976","DOIUrl":"https://doi.org/10.1080/09377255.2019.1602976","url":null,"abstract":"ABSTRACT The aim of this study was to reduce the total resistance of a multi-purpose wind offshore supply vessel by optimising its hull. Resistance was computed using a potential flow boundary element method and a Reynolds-averaged Navier–Stokes equations solver. Optimised hull forms were obtained for the ship advancing at different ship speeds under calm water conditions, employing the two multi-objective optimisation algorithms, Non-dominated Sorting Genetic Algorithm II (NSGA-II) and Multi-Objective Simulated Annealing (MOSA). Using NSGA-II yielded slightly larger reductions of total resistances than MOSA. The greatest reductions were achieved at ship speeds between 11 and 14knots. At these speeds, a thinner and longer bulbous bow reduced resistance. At speeds greater than 15knots, a bloated bulbous bow was more helpful to reduce resistance.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2019.1602976","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47946557","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}
Pub Date : 2020-02-28DOI: 10.1080/09377255.2020.1729454
O. Kinaci, Metin Kemal Gokce, C. Delen
ABSTRACT In this study, resistance and propulsion characteristics of the Duisburg Test Case (DTC) Post-Panamax Container Ship were investigated experimentally and numerically. The model scale was different from other studies in the literature. First, resistance experiments with uncertainty analysis were carried out in the Ata Nutku Ship Model Testing Laboratory at Istanbul Technical University. Good agreement was found with other experiments conducted at bigger scales. Then; using the experimental resistance results, self-propulsion point was estimated with a quick methodology recently published in the literature. The study was finalized with numerical simulations of bare hull resistance and self-propulsion tests. Comparisons with other studies having different scales or adopting different methods were made and agreements were satisfactory. Robustness of the self-propulsion estimation methodology was noted, considering its easy implementation and accurate predictions. Resistance experiments and propulsion parameters obtained in this study are expected to form a basis for predicting manoeuvring abilities of DTC.
{"title":"Resistance experiments and self-propulsion estimations of Duisburg Test Case at 1/100 scale","authors":"O. Kinaci, Metin Kemal Gokce, C. Delen","doi":"10.1080/09377255.2020.1729454","DOIUrl":"https://doi.org/10.1080/09377255.2020.1729454","url":null,"abstract":"ABSTRACT In this study, resistance and propulsion characteristics of the Duisburg Test Case (DTC) Post-Panamax Container Ship were investigated experimentally and numerically. The model scale was different from other studies in the literature. First, resistance experiments with uncertainty analysis were carried out in the Ata Nutku Ship Model Testing Laboratory at Istanbul Technical University. Good agreement was found with other experiments conducted at bigger scales. Then; using the experimental resistance results, self-propulsion point was estimated with a quick methodology recently published in the literature. The study was finalized with numerical simulations of bare hull resistance and self-propulsion tests. Comparisons with other studies having different scales or adopting different methods were made and agreements were satisfactory. Robustness of the self-propulsion estimation methodology was noted, considering its easy implementation and accurate predictions. Resistance experiments and propulsion parameters obtained in this study are expected to form a basis for predicting manoeuvring abilities of DTC.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1729454","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41953849","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}
Pub Date : 2020-02-09DOI: 10.1080/09377255.2020.1724647
V. Shabarov, Pavel Kaliasov, F. Peplin
ABSTRACT Accurate determination of longitudinal stability characteristics of wing-in-ground (WIG) effect vehicles is an essential step in their design. In order to estimate WIG vehicle’s stability, one needs to determine aerodynamic derivatives, including unsteady ones. The latter are very hard to obtain via wind tunnel tests, so traditionally they are expressed via steady derivatives. The method presented in this paper allows calculating unsteady aerodynamic derivatives by means of Reynolds-averaged Navier–Stokes simulations. The effect of different aerodynamic derivatives on stability characteristics is investigated. It is demonstrated that the decrement is two times greater in case of taking into account the unsteady aerodynamic derivatives calculated according to the presented method.
{"title":"Influence of ground effect on longitudinal aerodynamic damping of wing-in-ground effect vehicles","authors":"V. Shabarov, Pavel Kaliasov, F. Peplin","doi":"10.1080/09377255.2020.1724647","DOIUrl":"https://doi.org/10.1080/09377255.2020.1724647","url":null,"abstract":"ABSTRACT Accurate determination of longitudinal stability characteristics of wing-in-ground (WIG) effect vehicles is an essential step in their design. In order to estimate WIG vehicle’s stability, one needs to determine aerodynamic derivatives, including unsteady ones. The latter are very hard to obtain via wind tunnel tests, so traditionally they are expressed via steady derivatives. The method presented in this paper allows calculating unsteady aerodynamic derivatives by means of Reynolds-averaged Navier–Stokes simulations. The effect of different aerodynamic derivatives on stability characteristics is investigated. It is demonstrated that the decrement is two times greater in case of taking into account the unsteady aerodynamic derivatives calculated according to the presented method.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1724647","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44323536","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}
Pub Date : 2020-01-02DOI: 10.1080/09377255.2020.1718377
S. Ehlers
The papers entitled “Investigation of a semi-submersible floating wind turbine in surge decay using CFD”, “Self-aligning behaviour of a passively yawing floating offshore wind turbine”, “Model scale investigation of aspects influencing the ice resistance of ships sailing ahead in level ice”, and “A partitioned solution approach for the simulation of the dynamic behaviour of flexible marine propellers” were also presented at the 1st Ship Technology Research Conference on the Status of Maritime Research held in Hamburg on 28th and 29th June 2018. The conference which takes place every other year serves as a platform for the exchange of the latest research results, with a view to making these available on an international basis.
{"title":"Foreword","authors":"S. Ehlers","doi":"10.1080/09377255.2020.1718377","DOIUrl":"https://doi.org/10.1080/09377255.2020.1718377","url":null,"abstract":"The papers entitled “Investigation of a semi-submersible floating wind turbine in surge decay using CFD”, “Self-aligning behaviour of a passively yawing floating offshore wind turbine”, “Model scale investigation of aspects influencing the ice resistance of ships sailing ahead in level ice”, and “A partitioned solution approach for the simulation of the dynamic behaviour of flexible marine propellers” were also presented at the 1st Ship Technology Research Conference on the Status of Maritime Research held in Hamburg on 28th and 29th June 2018. The conference which takes place every other year serves as a platform for the exchange of the latest research results, with a view to making these available on an international basis.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1718377","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49619914","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}
Pub Date : 2020-01-02DOI: 10.1080/09377255.2018.1555986
S. Netzband, C. Schulz, M. Abdel‐Maksoud
ABSTRACT Floating offshore wind turbines are a promising concept for expanding offshore wind energy. In comparison with fix-founded offshore wind turbines, the overall costs are less dependent on water depths, which leads to a variety of potential locations and markets worldwide. Furthermore, floating platforms allow for new structural designs with the potential to save material and installation costs. In this paper, a self-aligning platform equipped with a 6 MW turbine is presented. The platform is moored on a single point and uses a turret buoy to be able to rotate freely around its anchor point. A downwind rotor and an airfoil-shaped tower induce self-aligning turning moments to passively follow changes of the wind direction. The first order boundary element method panMARE is used to simulate the motion behaviour considering aerodynamic, hydrodynamic and mooring loads. The self-aligning capability is demonstrated under partial turbine load for steady and dynamic conditions with waves and current.
{"title":"Self-aligning behaviour of a passively yawing floating offshore wind turbine","authors":"S. Netzband, C. Schulz, M. Abdel‐Maksoud","doi":"10.1080/09377255.2018.1555986","DOIUrl":"https://doi.org/10.1080/09377255.2018.1555986","url":null,"abstract":"ABSTRACT Floating offshore wind turbines are a promising concept for expanding offshore wind energy. In comparison with fix-founded offshore wind turbines, the overall costs are less dependent on water depths, which leads to a variety of potential locations and markets worldwide. Furthermore, floating platforms allow for new structural designs with the potential to save material and installation costs. In this paper, a self-aligning platform equipped with a 6 MW turbine is presented. The platform is moored on a single point and uses a turret buoy to be able to rotate freely around its anchor point. A downwind rotor and an airfoil-shaped tower induce self-aligning turning moments to passively follow changes of the wind direction. The first order boundary element method panMARE is used to simulate the motion behaviour considering aerodynamic, hydrodynamic and mooring loads. The self-aligning capability is demonstrated under partial turbine load for steady and dynamic conditions with waves and current.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2018.1555986","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46886771","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}
Pub Date : 2020-01-02DOI: 10.1080/09377255.2019.1576390
D. Myland, S. Ehlers
ABSTRACT For a reliable prediction of the total resistance in ice in an early ship design stage, it is of great importance to have knowledge on the different influencing aspects. Three of the quite poorly investigated aspects of ship resistance in ice are evaluated for a contemporary common ice-breaking ship type with model tests in ice: The different components of the total resistance in ice are investigated by tests in pre-sawn ice. The additional resistance of a skeg in the bow area is analysed with model tests in ice with an instrumented skeg. The ship bottom ice coverage is determined by means of an underwater image analysis methodology. The results of these investigations are given and discussed.
{"title":"Model scale investigation of aspects influencing the ice resistance of ships sailing ahead in level ice","authors":"D. Myland, S. Ehlers","doi":"10.1080/09377255.2019.1576390","DOIUrl":"https://doi.org/10.1080/09377255.2019.1576390","url":null,"abstract":"ABSTRACT For a reliable prediction of the total resistance in ice in an early ship design stage, it is of great importance to have knowledge on the different influencing aspects. Three of the quite poorly investigated aspects of ship resistance in ice are evaluated for a contemporary common ice-breaking ship type with model tests in ice: The different components of the total resistance in ice are investigated by tests in pre-sawn ice. The additional resistance of a skeg in the bow area is analysed with model tests in ice with an instrumented skeg. The ship bottom ice coverage is determined by means of an underwater image analysis methodology. The results of these investigations are given and discussed.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2019.1576390","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41379165","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}
Pub Date : 2020-01-02DOI: 10.1080/09377255.2018.1555987
S. Burmester, G. Vaz, S. Gueydon, O. el Moctar
ABSTRACT The hydrodynamic damping estimation of the surge motion and the flow characteristics of a moored semi-submersible floating offshore wind turbine is the focus of this paper. The numerical surge decay tests were investigated using a Reynolds-Averaged Navier–Stokes solver. Solution verification on the numerical simulations was performed by estimation of the numerical errors and uncertainties. A linear stiffness matrix and a non-linear quasi-static mooring model were used in the equations of motion. Several surge decay simulations were performed to understand the effects of wave radiation, coupled motions and non-linear moorings on the hydrodynamic damping and the flow field around the floater. The numerical results were compared with experimental data. The free surface had major effects on the hydrodynamic damping and the flow field.
摘要本文研究了系泊式半潜式海上风力机喘振运动和流动特性的水动力阻尼估计。采用reynolds - average Navier-Stokes解算器对激波衰减进行了数值研究。通过对数值误差和不确定性的估计，对数值模拟结果进行了验证。运动方程采用线性刚度矩阵和非线性准静态系泊模型。为了了解波浪辐射、耦合运动和非线性系泊对浮子水动力阻尼和周围流场的影响，进行了几次浪涌衰减模拟。数值计算结果与实验数据进行了比较。自由表面对流体动力阻尼和流场有重要影响。
{"title":"Investigation of a semi-submersible floating wind turbine in surge decay using CFD","authors":"S. Burmester, G. Vaz, S. Gueydon, O. el Moctar","doi":"10.1080/09377255.2018.1555987","DOIUrl":"https://doi.org/10.1080/09377255.2018.1555987","url":null,"abstract":"ABSTRACT The hydrodynamic damping estimation of the surge motion and the flow characteristics of a moored semi-submersible floating offshore wind turbine is the focus of this paper. The numerical surge decay tests were investigated using a Reynolds-Averaged Navier–Stokes solver. Solution verification on the numerical simulations was performed by estimation of the numerical errors and uncertainties. A linear stiffness matrix and a non-linear quasi-static mooring model were used in the equations of motion. Several surge decay simulations were performed to understand the effects of wave radiation, coupled motions and non-linear moorings on the hydrodynamic damping and the flow field around the floater. The numerical results were compared with experimental data. The free surface had major effects on the hydrodynamic damping and the flow field.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2018.1555987","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48308166","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}
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