R. Pellegrini, A. Serani, M. Diez, M. Visonneau, J. Wackers
{"title":"Towards Automatic Parameter Selection for Multifidelity Surrogate-Based Optimization","authors":"R. Pellegrini, A. Serani, M. Diez, M. Visonneau, J. Wackers","doi":"10.2218/marine2021.6794","DOIUrl":"https://doi.org/10.2218/marine2021.6794","url":null,"abstract":"","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"69 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130769957","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}
. Simulation results are presented for a well established ship hydrodynamics validation case with the Japan Bulk Carrier (JBC). The results include the ship position, forces on the hull, water surface deformation and the stern flow. Simulation results are compared with measurements for all these quantities. The open source software OpenFOAM was employed, with finite volume numerics, RANS turbulence modelling, the volume-of-fluid method for the free surface, and ship motion functionality. In order to enhance the reproducibility of the results, the data files of the simulation case are made freely available. In combination with open source software, this allows for other research groups to re-simulate, modify and improve the case. Practical aspects of making this type of simulation data available are also discussed in the paper.
{"title":"Fully reproducible RANS ship hydrodynamics for the JBC validation case","authors":"Linnea Sjökvist, M. Liefvendahl, M. Winroth","doi":"10.2218/marine2021.6825","DOIUrl":"https://doi.org/10.2218/marine2021.6825","url":null,"abstract":". Simulation results are presented for a well established ship hydrodynamics validation case with the Japan Bulk Carrier (JBC). The results include the ship position, forces on the hull, water surface deformation and the stern flow. Simulation results are compared with measurements for all these quantities. The open source software OpenFOAM was employed, with finite volume numerics, RANS turbulence modelling, the volume-of-fluid method for the free surface, and ship motion functionality. In order to enhance the reproducibility of the results, the data files of the simulation case are made freely available. In combination with open source software, this allows for other research groups to re-simulate, modify and improve the case. Practical aspects of making this type of simulation data available are also discussed in the paper.","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"1202 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128632740","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}
Piecewise Linear Interface Calculation (PLIC) schemes have been extensively employed in the Volume of Fluid (VOF) method to capture the interface between water and air in marine applications. The Adaptive Mesh Refinement (AMR) is often adopted to increase the local mesh resolution dynamically within the cells which are close to or contain the interface. Dynamic overset meshes can be especially useful in applications involving component motions involving ship/offshore platform hydrodynamics, semi-submerged propellers, water entry/exiting, etc. An adaptive PLIC-VOF method with overset mesh for static objects has been introduced in the present study. Simulations are performed under the framework of OpenFOAM with a modified flow solver. Numerical simulations of two dam-breaking problems with overset meshes and adaptive PLIC-VOF method have been successfully performed. An extension of solid body movement supporting is currently ongoing.
{"title":"The Adaptive PLIC-VOF Method with Overset Meshes","authors":"Dezhi Dai, A. Y. Tong","doi":"10.2218/marine2021.6834","DOIUrl":"https://doi.org/10.2218/marine2021.6834","url":null,"abstract":"Piecewise Linear Interface Calculation (PLIC) schemes have been extensively employed in the Volume of Fluid (VOF) method to capture the interface between water and air in marine applications. The Adaptive Mesh Refinement (AMR) is often adopted to increase the local mesh resolution dynamically within the cells which are close to or contain the interface. Dynamic overset meshes can be especially useful in applications involving component motions involving ship/offshore platform hydrodynamics, semi-submerged propellers, water entry/exiting, etc. An adaptive PLIC-VOF method with overset mesh for static objects has been introduced in the present study. Simulations are performed under the framework of OpenFOAM with a modified flow solver. Numerical simulations of two dam-breaking problems with overset meshes and adaptive PLIC-VOF method have been successfully performed. An extension of solid body movement supporting is currently ongoing.","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127819984","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}
Yadong Jiang, W. Finnegan, F. Wallace, M. Flanagan, T. Flanagan, J. Goggins
{"title":"Numerical Modelling and Structural Analysis of a 1 MW Tidal Turbine Blade","authors":"Yadong Jiang, W. Finnegan, F. Wallace, M. Flanagan, T. Flanagan, J. Goggins","doi":"10.2218/marine2021.6799","DOIUrl":"https://doi.org/10.2218/marine2021.6799","url":null,"abstract":"","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127882937","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}
. A data-driven and equation-free approach is proposed and discussed to model ships maneuvers in waves, based on the dynamic mode decomposition (DMD). DMD is a dimensionality-reduction/reduced-order modeling method, which provides a linear finite-dimensional representation of a possibly nonlinear system dynamics by means of a set of modes with associated oscillation frequencies and decay/growth rates. DMD also allows for short-term future estimates of the system’s state, which can be used for real-time prediction and control. Here, the objective of the DMD is the analysis and forecast of the trajectories/motions/forces of ships operating in waves, offering a complementary efficient method to equation-based system identification approaches. Results are presented for the course keeping of a free-running naval destroyer (5415M) in irregular stern-quartering waves and for the free-running KRISO Container Ship (KCS) performing a turning circle in regular waves. Results are overall promising and show how DMD is able to identify the most important modes and forecast the system’s state with reasonable accuracy upto two wave encounter periods.
{"title":"Data-Driven Modeling of Ship Maneuvers in Waves via Dynamic Mode Decomposition","authors":"M. Diez, A. Serani, E. Campana, F. Stern","doi":"10.2218/marine2021.6852","DOIUrl":"https://doi.org/10.2218/marine2021.6852","url":null,"abstract":". A data-driven and equation-free approach is proposed and discussed to model ships maneuvers in waves, based on the dynamic mode decomposition (DMD). DMD is a dimensionality-reduction/reduced-order modeling method, which provides a linear finite-dimensional representation of a possibly nonlinear system dynamics by means of a set of modes with associated oscillation frequencies and decay/growth rates. DMD also allows for short-term future estimates of the system’s state, which can be used for real-time prediction and control. Here, the objective of the DMD is the analysis and forecast of the trajectories/motions/forces of ships operating in waves, offering a complementary efficient method to equation-based system identification approaches. Results are presented for the course keeping of a free-running naval destroyer (5415M) in irregular stern-quartering waves and for the free-running KRISO Container Ship (KCS) performing a turning circle in regular waves. Results are overall promising and show how DMD is able to identify the most important modes and forecast the system’s state with reasonable accuracy upto two wave encounter periods.","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125014872","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":"Marine propeller noise propagation within an ocean waveguide","authors":"G. Petris, M. Cianferra, V. Armenio","doi":"10.2218/marine2021.6831","DOIUrl":"https://doi.org/10.2218/marine2021.6831","url":null,"abstract":"","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129308760","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 investigation of curvature effect on ship hydrodynamics in confined curved channels","authors":"Bo Yang, S. Kaidi, E. Lefrançois","doi":"10.2218/marine2021.6790","DOIUrl":"https://doi.org/10.2218/marine2021.6790","url":null,"abstract":"","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128966595","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":"The Influence of Leading-Edge Tubercles on the Wake Flow Dynamics of a Marine Rudder","authors":"Moritz Troll, Weichao Shi, Callum Stark","doi":"10.2218/marine2021.6802","DOIUrl":"https://doi.org/10.2218/marine2021.6802","url":null,"abstract":"","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"44 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120920608","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}
. Recent research shows that planks of various roughness can be towed in water, and the frictional resistance obtained can be extended to hull forms. Thus, the resistance is determined experimentally with the help of towing tank setup. The estimation of resistance of planks of varied roughness by towing them in the towing tank will help determine frictional resistance of the ship. In the studies of Schultz (Schultz 2007), it is reported that higher drag values are reported for small coverage of barnacles, and smaller drag values are reported for large coverage. The skin friction coefficients for different plate lengths are extrapolated to ship size and speed. Usually, the variation in drag coefficients is minimal for planks of length above 50 feet.
{"title":"Alternate Method For Determining Resistance Of Ship With Fouled Hull","authors":"Della Thomas, S. Surendran, N. J. Vasa","doi":"10.2218/marine2021.6856","DOIUrl":"https://doi.org/10.2218/marine2021.6856","url":null,"abstract":". Recent research shows that planks of various roughness can be towed in water, and the frictional resistance obtained can be extended to hull forms. Thus, the resistance is determined experimentally with the help of towing tank setup. The estimation of resistance of planks of varied roughness by towing them in the towing tank will help determine frictional resistance of the ship. In the studies of Schultz (Schultz 2007), it is reported that higher drag values are reported for small coverage of barnacles, and smaller drag values are reported for large coverage. The skin friction coefficients for different plate lengths are extrapolated to ship size and speed. Usually, the variation in drag coefficients is minimal for planks of length above 50 feet.","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113969279","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}
Konstantin Missios, N. Jacobsen, J. Roenby, Kasper Moeller
We consider the interfacial flow in and around porous structures in coastal and marine engineering. During recent years, interfacial flow through porous media has been repeatedly simulated with Computational Fluid Dynamics (CFD) based on algebraic Volume Of Fluid (VOF) methods (Jensen et al., 2014; Higuera et al., 2014). Here, we present an implementation of a porous medium interfacial flow solver based on the geometric VOF method, isoAdvector (Roenby et al., 2016; Roenby et al., 2017). In our implementation, the porous media is treated without resolving the actual pore geometry. Rather, the porous media, pores, and rigid structure are considered a continuum and the effects of porosity on the fluid flow are modelled through source terms in the Navier-Stokes equations, including Darcy-Forchheimer forces, added mass force and accounting for the part of mesh cells that are occupied by the solid material comprising the skeleton of the porous medium. The governing equations are adopted from the formulation by Jensen et al. (2014). For the interface advection using isoAdvector, we also account for the reduced cell volume available for fluid flow and for the increase in the interface front velocity caused by a cell being partially filled with solid material. The solver is implemented in the open source CFD library OpenFOAM ® . It is validated using two case setups: 1) A pure passive advection test case to compare the isolated advection algorithm against a known analytical soltuion and 2) a porous dam break case by Liu et al. (1999) where both numerical and experimental results are available for comparison. We find good agreement with numerical and experimental results. For both cases the interface sharpness, shape conservation as well as volume conservation and boundedness are demonstrated to be very good. The solver is released as open source for the benefit of the coastal and marine CFD community.
我们考虑了海岸和海洋工程中多孔结构内部和周围的界面流动。近年来，基于代数流体体积(VOF)方法的计算流体动力学(CFD)反复模拟了多孔介质中的界面流动(Jensen et al.， 2014;Higuera et al.， 2014)。在这里，我们提出了一个基于几何VOF方法的多孔介质界面流动求解器的实现，isoAdvector (Roenby等人，2016;Roenby等人，2017)。在我们的实施中，多孔介质的处理没有解决实际的孔隙几何。相反，多孔介质、孔隙和刚性结构被认为是一个连续体，孔隙度对流体流动的影响是通过Navier-Stokes方程中的源项来建模的，包括Darcy-Forchheimer力、附加质量力和由构成多孔介质骨架的固体物质占据的网格单元部分。控制方程采用Jensen et al.(2014)的公式。对于使用isoAdvector的界面平流，我们还考虑了可用于流体流动的细胞体积的减少以及由细胞部分填充固体材料引起的界面前速度的增加。求解器在开源CFD库OpenFOAM®中实现。它使用两种情况设置进行验证:1)一个纯被动平流测试案例，将孤立平流算法与已知解析解进行比较;2)Liu等人(1999)的多孔溃坝案例，其中数值和实验结果均可用于比较。计算结果与实验结果吻合较好。在这两种情况下，界面清晰度、形状守恒、体积守恒和有界性都非常好。为了沿海和海洋CFD社区的利益，求解器作为开源发布。
{"title":"Using the isoAdvector geometric VoF method for interfacial flows through porous media","authors":"Konstantin Missios, N. Jacobsen, J. Roenby, Kasper Moeller","doi":"10.2218/marine2021.6811","DOIUrl":"https://doi.org/10.2218/marine2021.6811","url":null,"abstract":"We consider the interfacial flow in and around porous structures in coastal and marine engineering. During recent years, interfacial flow through porous media has been repeatedly simulated with Computational Fluid Dynamics (CFD) based on algebraic Volume Of Fluid (VOF) methods (Jensen et al., 2014; Higuera et al., 2014). Here, we present an implementation of a porous medium interfacial flow solver based on the geometric VOF method, isoAdvector (Roenby et al., 2016; Roenby et al., 2017). In our implementation, the porous media is treated without resolving the actual pore geometry. Rather, the porous media, pores, and rigid structure are considered a continuum and the effects of porosity on the fluid flow are modelled through source terms in the Navier-Stokes equations, including Darcy-Forchheimer forces, added mass force and accounting for the part of mesh cells that are occupied by the solid material comprising the skeleton of the porous medium. The governing equations are adopted from the formulation by Jensen et al. (2014). For the interface advection using isoAdvector, we also account for the reduced cell volume available for fluid flow and for the increase in the interface front velocity caused by a cell being partially filled with solid material. The solver is implemented in the open source CFD library OpenFOAM ® . It is validated using two case setups: 1) A pure passive advection test case to compare the isolated advection algorithm against a known analytical soltuion and 2) a porous dam break case by Liu et al. (1999) where both numerical and experimental results are available for comparison. We find good agreement with numerical and experimental results. For both cases the interface sharpness, shape conservation as well as volume conservation and boundedness are demonstrated to be very good. The solver is released as open source for the benefit of the coastal and marine CFD community.","PeriodicalId":367395,"journal":{"name":"The 9th Conference on Computational Methods in Marine Engineering (Marine 2021)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116335430","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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