Journal of Ship Research最新文献

{"title":"Influence of Ship Speed and Heading Profiles on Fatigue Damage Accumulation for a Naval Vessel","authors":"Ian Thompson, B. Ellis","doi":"10.5957/JOSR.10180092","DOIUrl":"https://doi.org/10.5957/JOSR.10180092","url":null,"abstract":"Ship speed and heading distributions are essential inputs for spectral fatigue analysis, and both may depend on wave conditions. Because rough-weather operational changes are rarely well defined, uncertainties in these distributions can introduce error in fatigue assessments. The influence of speed and relative heading distribution on fatigue estimates has not been thoroughly examined in the existing literature. This study investigates the influence of ship speed and relative heading distributions on fatigue damage accumulation of two sister naval ships. To represent uncertainties, 16 different operating profiles were used, including a baseline profile created from operator surveys and measurements. Fatigue damage estimates are calculated from a spectral analysis of four structural locations near midship. A linear frequency-domain seakeeping code provides the wave loads. The corresponding stresses are calculated using linear finite element analysis. Efforts to maintain seakeeping quality and crew readiness are reflected in the baseline profile with rough-weather speed and course changes. Ignoring these operational changes leads to reductions in estimated fatigue damage of up to 34% relative to the baseline estimate. This nonconservative result emphasizes the importance of understanding how operators manage rough wave conditions.","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46443589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-fidelity Bayesian Optimization of SWATH Hull Forms","authors":"L. Bonfiglio, P. Perdikaris, S. Brizzolara","doi":"10.5957/JOSR.11180102","DOIUrl":"https://doi.org/10.5957/JOSR.11180102","url":null,"abstract":"This study presents a multi-fidelity framework that enables the construction of surrogate models capable of capturing complex correlations between design variables and quantities of interest. Resistance in calm water is investigated for a SWATH hull in a multidimensional design space using a new method to derive high-quality response surfaces through machine learning techniques based on a low number of high-fidelity computations and a larger number of less-expensive low-fidelity computations. First, a verification and validation study is presented with the goal of comparing and ranking numerical methods against experiments performed on a conventional SWATH geometry. Then, the hull geometry of a new family of unconventional SWATH hull forms with twin counter-canted struts is parametrically defined and sequentially refined using multi-fidelity Bayesian optimization. Ship resistance in calm water is finally predicted using observations from two different fidelity levels. We demonstrate that the multi-fidelity optimization framework is successful in obtaining an optimized design using a small number of high-fidelity computations and a larger number of low-fidelity computations. Simulation and optimization costs are reduced by orders of magnitude, providing accurate certificates of fidelity for the performance of the proposed design.","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41566683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Added Resistance and Speed Loss of a Ship Found Using Onboard Monitoring Data","authors":"Øyvind Øksnes Dalheim, S. Steen","doi":"10.5957/JOSR.10180095","DOIUrl":"https://doi.org/10.5957/JOSR.10180095","url":null,"abstract":"Prediction of the added resistance or corresponding speed loss in real sea conditions is essential to evaluate the performance of a ship. Assessment of the environmental impact on vessel performance is essential for route and cargo planning, optimization of fuel consumption and design, and configuration of engines and the main propulsion system. In the present study, added resistance and speed loss in real sea conditions are evaluated from1 year of onboard monitoring data of a platform supply vessel (PSV) operating in the North Sea. The true sea margin is shown on an annual basis. Relative contributions from environmental conditions and vessel operation control are presented. Results are compared with model experiments and existing numerical methods for prediction of added resistance and speed loss in waves. The study shows that added resistance due to waves for this PSV is significantly larger than predicted by conventional frequency-domain calculations or model tests. No reason for the deviation is found, but it is anticipated that a combination of effects of longitudinal mass radius of gyration, differences in wavelength and steepness in model tests and reality, and nonlinear effects (not accounted for in the numerical calculations) is partly responsible for the deviations. For ships having similar main dimensions, the conventional ways of predicting added resistance or speed loss in waves is nonconservative, and improved methods should be sought.","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45041208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Method for the Prediction of Extreme Ship Responses Using Design-Event Theory and Computational Fluid Dynamics","authors":"Wen-tao Xu, G. Filip, K. Maki","doi":"10.5957/jsr.2020.64.1.48","DOIUrl":"https://doi.org/10.5957/jsr.2020.64.1.48","url":null,"abstract":"The design of a naval vessel requires accurate estimation of the extreme loads and motions that it will experience during its lifetime. Operation in large seaways in which the ship-wave interaction is highly nonlinear and transient leads to design events such as maximum internal loads due to global wave bending, local slamming loads, extreme roll, combinations of the global wave bending and local slamming, and many others. In this article, a method is presented that allows for nonlinear analysis to be used to predict events with user-specified rareness. The core of the method combines probability, frequency, and time-domain analyses to generate short time-window sea environments that lead to extreme dynamical events. The Office of Naval Research Tumblehome geometry is analyzed for the extreme roll angle when advancing in stern quartering irregular seas.\u0000 \u0000 \u0000 The design of a naval vessel requires accurate estimation of extreme loads and motions that it will experience during its lifetime. Specific quantities of interest are the maximum slamming load during wet-deck impact, maximum acceleration at different locations on the vessel, maximum green-water load on the bow structure or helicopter deck, maximum roll angle, or frequency of occurrence of capsize, to name a few. It is important to recognize that a ship lifetime is decades long, and the exposure time in different severe storms over the lifetime is of the order of weeks, if not months. Furthermore, because of the random nature of the sea and, hence, the dynamical response of the ship, the extreme response is also random and should be characterized statistically. This means that a single lifetime realization in a given seaway by either model tests or numerical simulation only gives one sample of the extreme response, and multiple lifetime realizations are required to characterize the extreme response.\u0000","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43500519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reducing Undesired Wave Reflection at Domain Boundaries in 3D Finite Volume-Based Flow Simulations via Forcing Zones","authors":"R. Perić, M. Abdel‐Maksoud","doi":"10.5957/jsr.2020.64.1.23","DOIUrl":"https://doi.org/10.5957/jsr.2020.64.1.23","url":null,"abstract":"This article reviews different types of forcing zones (sponge layers, damping zones, relaxation zones, etc.) as used in finite volume-based flow simulations to reduce undesired wave reflections at domain boundaries, with special focus on the case of strongly reflecting bodies subjected to long-crested incidence waves. Limitations and possible sources of errors are discussed. A novel forcing-zone arrangement is presented and validated via three-dimensional (3D) flow simulations. Furthermore, a recently published theory for predicting the forcing-zone behavior was investigated with regard to its relevance for practical 3D hydrodynamics problems. It was found that the theory can be used to optimally tune the case-dependent parameters of the forcing zones before running the simulations.\u0000 \u0000 \u0000 Wave reflections at the boundaries of the computational domain can cause significant errors in flow simulations, and must therefore be reduced. In contrast to boundary element codes, where much progress in this respect has been made decades ago (see e.g., Clement 1996; Grilli &Horillo 1997), for finite volume-based flow solvers, there are many unresolved questions, especially:How to reliably reduce reflections and disturbances from the domain boundaries?How to predict the amount of undesired wave reflection before running the simulation?\u0000 This work aims to provide further insight to these questions for flow simulations based on Navier-Stokes-type equations (Reynolds-averaged Navier-Stokes, Euler equations, Large Eddy Simulations, etc.), when using forcing zones to reduce undesired reflections. The term \"forcing zones\" is used here to describe approaches that gradually force the solution in the vicinity of the boundary towards some reference solution, as described in Section 2; some examples are absorbing layers, sponge layers, damping zones, relaxation zones, or the Euler overlay method (Mayer et al. 1998; Park et al. 1999; Chen et al. 2006; Choi &Yoon 2009; Jacobsen et al. 2012; Kimet al. 2012; Schmitt & Elsaesser 2015; Perić & Abdel-Maksoud 2016a; Vukčević et al. 2016).\u0000","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48885362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probability of Ship High-Runs from Phase-Space Data","authors":"I. Kontolefas, K. Spyrou","doi":"10.5957//josr.09180072","DOIUrl":"https://doi.org/10.5957//josr.09180072","url":null,"abstract":"A clustering scheme has been applied for capturing qualitatively different surge motion patterns in the phase space. The scheme enables the identification of \"high-run\" incidents as soon as such motions are triggered and while their phenomenology has not yet been well developed. A \"high run\" is a surf-riding-like behavior, appearing in irregular following seas. The concept of finite-time coherent sets is exploited for deriving estimates of the probability of high-runs. The method is verified by identifying independently the corresponding hyperbolic Lagrangian coherent structures; then, consistency is sought between the two approaches. An important feature of the method is that it does not rely on the use of some empirical criterion for the high-run threshold, such as one based on the exceedance of an arbitrary high-speed level. Despite its computational burden, the proposed scheme offers \"objective\" statistical information on a ship's high-run tendency that can be used for benchmarking simpler (approximative) probability calculation schemes.\u0000 \u0000 \u0000 Current efforts to assess a ship's tendency for abnormal behavior in extreme seas are still limited from our inadequate grasp of the full variety of nonlinear ship motion phenomena that could be realized in an irregular seaway. A classification of these motion patterns would provide a sound basis for developing probabilistic calculation methods of ship operability and safety in extreme seas. A few recent research efforts in our group have been related to this target. In one case, it was endeavored to distinguish ship high-runs from ordinary surging, by engaging the concept of instantaneous wave celerity (Spyrou et al. 2014). In another, the derivation of a practical metric for the probability of high-run was pursued (Belenky et al. 2016). Also, high-run and broaching-to statistics were produced through a direct approach based on assigning prescriptive exceedance thresholds (Spyrou et al. 2016b). Moreover, the theory of surf-riding was extended for bichromatic waves, revealing some rather unexpected types of motion (Spyrou et al. 2018). Even richer phenomena could be conjectured for a multifrequency environment.\u0000","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48871435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of Hydrodynamic Characteristics of Underwater Hull Cleaning Robot Using CFD Techniques","authors":"Yanzhen Chen, Yi-Huai Hu, Tai-You Wang, E. Munyao, Sheng-Long Zhang, Jiawei Jiang, Cheng Ma","doi":"10.5957/JOSR.07180039","DOIUrl":"https://doi.org/10.5957/JOSR.07180039","url":null,"abstract":"In this article, an underwater hull cleaning robot model based on propeller thrust adsorption is established for near-wall conditions. By using a computational fluid dynamics method, which is proven feasible by comparing a calm water resistance simulation with its experimental data, the influence of floating body shape and wall distance on its hydrodynamic characteristics is studied. Then, the body force propeller model is used to analyze the interaction between the propeller flow field and the flow field around the underwater cleaning robot. Compared with the cuboid floating body, the results show that the streamlined appearance can greatly reduce front high-pressure area, the pressure drag between the front and rear ends, and the viscous resistance. Its drag coefficient is reduced by 11.5%. The presence of the hull will increase the pressure drag and viscous resistance of the underwater hull cleaning robot, which is similar to the \"shallow water blockage effect\" of a ship. For this model, the decrease in the wall distance results in a progressive increase in resistance and drag coefficient. As the wall distance is .15 m, the drag coefficient of the underwater hull cleaning robot increases by 4.55%, compared with the limitless water field. For the body force propeller model, the study indicates that when the flow velocity is constant, both the resistance in the forward direction and the adsorption force of the underwater hull cleaning robot increase with the increase in rotation speed of the propeller. The thrust propeller generates a higher increase in resistance and a lower increase in adsorption force compared with the adsorption of the propeller. When the rotation speed is constant, the resistance of the underwater hull cleaning robot increases, with the increase in the flow velocity, and the adsorption force of the underwater hull cleaning robot first decreases and then increases. Therefore, it must be fully considered that the significant influence of the hull and the propeller on the underwater hull cleaning robot can provide theoretical guidance for future related design and research.","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46910080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EFD and CFD Study of Forces, Ship Motions, and Flow Field for KRISO Container Ship Model in Waves","authors":"P. Wu, Md. Al-Amin Hossain, Naoki Kawakami, Kento Tamaki, Htike Aung Kyaw, Ayaka Matsumoto, Y. Toda","doi":"10.5957/JSR.2020.64.1.61","DOIUrl":"https://doi.org/10.5957/JSR.2020.64.1.61","url":null,"abstract":"Ship motion responses and added resistance in waves have been predicted by a wide variety of computational tools. However, validation of the computational flow field still remains a challenge. In the previous study, the flow field around the Korea Research Institute for Ships and Ocean Engineering (KRISO) Very Large Crude-oil Carrier 2 tanker model with and without propeller condition and without rudder condition was measured by the authors, as well as the resistance and self-propulsion tests in waves. In this study, the KRISO container ship model appended with a rudder was used for the higher Froude number .26 and smaller block coefficient .65. The experiments were conducted in the Osaka University towing tank using a 3.2-m-long ship model for resistance and self-propulsion tests in waves. Viscous flow simulation was performed by using CFDShip-Iowa. The wave conditions proposed in Computational Fluid Dynamics (CFD) Workshop 2015 were considered, i.e., the wave-ship length ratio λ/L = .65, .85, 1.15, 1.37, 1.95, and calm water. The objective of this study was to validate CFD results by Experimental Fluid Dynamics (EFD) data for ship vertical motions, added resistance, and wake flow field. The detailed flow field for nominal wake and self-propulsion condition will be analyzed for λ/L = .65, 1.15, 1.37, and calm water. Furthermore, bilge vortex movement and boundary layer development on propeller plane, propeller thrust, and wake factor oscillation in waves will be studied.","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41646899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Investigation of DARPA Suboff Submarine Propelled with INSEAN E1619 Propeller for Self-Propulsion","authors":"Yasemin Arikan Özden, M. C. Özden, Ersin Demir, Sertaç Kurdoglu","doi":"10.5957/JOSR.09180084","DOIUrl":"https://doi.org/10.5957/JOSR.09180084","url":null,"abstract":"The Defense Advanced Research Projects Agency (DARPA) Suboff Submarine propelled by the Italian Ship Model Basin (INSEAN) E1619 propeller is extensively used in submarine validation studies. Although there are several numerical studies where the DARPA Suboff submarine is used in combination with E1619 propeller there are no experimental data available in open literature for the self-propulsion condition. In this article, the self-propulsion characteristics of the DARPA Suboff submarine model with INSEAN E1619 propeller obtained with experimental and numerical methods are presented and discussed by means of Taylor wake fraction, thrust deduction, hull efficiency, relative rotative efficiency, and propulsive efficiency. To experimentally investigate the submarine form, a self-propulsion experimental setup is designed and manufactured. Resistance and self-propulsion experiments are conducted in Istanbul Technical University Ata Nutku Ship Model Testing Laboratory. Resistance tests are carried out for three different speeds, and the results show good agreement with the published experimental results. Propulsion tests are conducted by using the load-varying self-propulsion test method for constant speed and seven different propeller rotation rates. Rotational speed, thrust, and torque forces at self-propulsion point are investigated. For the numerical computations a commercial Computational Fluid Dynamics (CFD) code is used. Propeller open water characteristics and nondimensional velocities behind the propeller are calculated. Self-propulsion point of the submarine and propeller assembly is also solved numerically and the results are compared with the results obtained from the experiments, and it is seen that especially the propeller rate of revolution and thrust force are predicted with very good approximation.","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":"63 1","pages":"235-250"},"PeriodicalIF":1.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46274204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent Developments in Computational Methods for the Analysis of Ducted Propellers in Open Water","authors":"J. Baltazar, J. Campos, J. Bosschers, D. Rijpkema","doi":"10.5957/JOSR.09180063","DOIUrl":"https://doi.org/10.5957/JOSR.09180063","url":null,"abstract":"This article presents an overview of the recent developments at Instituto Superior Técnico and Maritime Research Institute Netherlands in applying computational methods for the hydrodynamic analysis of ducted propellers. The developments focus on the propeller performance prediction in open water conditions using boundary element methods and Reynolds-averaged Navier-Stokes solvers. The article starts with an estimation of the numerical errors involved in both methods. Then, the different viscous mechanisms involved in the ducted propeller flow are discussed and numerical procedures for the potential flow solution proposed. Finally, the numerical predictions are compared with experimental measurements.\u0000 \u0000 \u0000 Ducted propellers have been widely used for marine applications. Nowadays, they may be found in tugs, trawlers, tankers, bulk ships, warships, and in dynamic positioning systems of offshore platforms or vessels. The duct may be classified as an accelerating or decelerating type. Accelerating ducts are often used to increase the efficiency and thrust of heavily loaded propellers. In the case of a decelerating duct, they are used to reduce the risk of cavitation and resulting noise.\u0000 The complex interaction which occurs between the propeller and duct makes the hydrodynamic design of such systems a complicated task. For the selection of the numerical simulation tool, the designer has to choose between a simplified method that predicts the main features of the flow field around the ducted propeller, and a more complex tool that provides detailed information in problematic areas such as the gap region between propeller and duct inner surface. On the other hand, model tests in a towing tank or cavitation tunnel may be seen as an alternative, but they are usually expensive. Presently, the development of an accurate and cost-effective numerical method for the design and analysis of ducted propellers is still not complete.\u0000","PeriodicalId":50052,"journal":{"name":"Journal of Ship Research","volume":"63 1","pages":"219-234"},"PeriodicalIF":1.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5957/JOSR.09180063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48765089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}