Pub Date : 2020-12-16DOI: 10.1080/09377255.2020.1857007
Shukui Liu, F. Sprenger, A. Papanikolaou, G. Dafermos, G. Zaraphonitis
ABSTRACT The paper presents a comprehensive numerical and experimental study on linear and nonlinear seakeeping phenomena, including six degree of freedom (DOF) ship motions, added resistance, drift forces and moments of the DTC containership in regular waves. Obtained numerical results by the 3D panel method NEWDRIFT+ of NTUA-SDL are systematically compared with corresponding experimental data generated within the SHOPERA project (2013–2016) at MARINTEK for various wave headings at low to moderate speeds. The herein presented experimental data are useful not only for validating the employed seakeeping software and others as a benchmark yardstick, but also for the deeper analysis of various open nonlinear seakeeping issues encountered in the prediction of the added resistance and drift forces of modern large containerships in waves.
{"title":"Experimental and numerical studies on linear and nonlinear seakeeping phenomena of the DTC ship in regular waves","authors":"Shukui Liu, F. Sprenger, A. Papanikolaou, G. Dafermos, G. Zaraphonitis","doi":"10.1080/09377255.2020.1857007","DOIUrl":"https://doi.org/10.1080/09377255.2020.1857007","url":null,"abstract":"ABSTRACT The paper presents a comprehensive numerical and experimental study on linear and nonlinear seakeeping phenomena, including six degree of freedom (DOF) ship motions, added resistance, drift forces and moments of the DTC containership in regular waves. Obtained numerical results by the 3D panel method NEWDRIFT+ of NTUA-SDL are systematically compared with corresponding experimental data generated within the SHOPERA project (2013–2016) at MARINTEK for various wave headings at low to moderate speeds. The herein presented experimental data are useful not only for validating the employed seakeeping software and others as a benchmark yardstick, but also for the deeper analysis of various open nonlinear seakeeping issues encountered in the prediction of the added resistance and drift forces of modern large containerships in waves.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1857007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49619889","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 : 2020-10-29DOI: 10.1080/09377255.2020.1836551
D. Ferreira González, U. Göttsche, S. Netzband, M. Abdel‐Maksoud
ABSTRACT The paper refers to a boundary element method (BEM) in the time domain for the simulation of wave-body interactions considering the free water surface. The approach solves the boundary integral equations for the velocity and the acceleration potential. The model of the free water surface in this approach is based on the mixed-Eulerian-Lagrangian (MEL) method. Validation results are presented for two well-studied test cases. The first validation case is dedicated to the free water surface. Here, the nonlinear wave loads on a truncated cylinder are analysed and compared with a higher-order panel method and experimental data. Second, results of a Wigley hull moving with forward speed in head waves are shown and compared with experimental results published by Kashiwagi. The validation results in both test cases generally show good agreement with published data and demonstrate the ability of BEM to investigate different types of hydrodynamic problems related to wave-body interactions.
{"title":"Advances on simulation of wave-body interactions under consideration of the nonlinear free water surface","authors":"D. Ferreira González, U. Göttsche, S. Netzband, M. Abdel‐Maksoud","doi":"10.1080/09377255.2020.1836551","DOIUrl":"https://doi.org/10.1080/09377255.2020.1836551","url":null,"abstract":"ABSTRACT The paper refers to a boundary element method (BEM) in the time domain for the simulation of wave-body interactions considering the free water surface. The approach solves the boundary integral equations for the velocity and the acceleration potential. The model of the free water surface in this approach is based on the mixed-Eulerian-Lagrangian (MEL) method. Validation results are presented for two well-studied test cases. The first validation case is dedicated to the free water surface. Here, the nonlinear wave loads on a truncated cylinder are analysed and compared with a higher-order panel method and experimental data. Second, results of a Wigley hull moving with forward speed in head waves are shown and compared with experimental results published by Kashiwagi. The validation results in both test cases generally show good agreement with published data and demonstrate the ability of BEM to investigate different types of hydrodynamic problems related to wave-body interactions.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1836551","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41956551","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 : 2020-10-15DOI: 10.1080/09377255.2020.1831840
P. Major, Houxiang Zhang, Hans Petter Hildre, Mathieu Edet
ABSTRACT Virtual prototyping of offshore operations (VPOO) is performed to plan and validate planning of infrequent or demanding operations characterized by high risk and low margins of error in hostile and remote environments distant from emergency response bases that require expensive equipment. Key elements of VPOO is the rapidity of virtual prototyping and the human-centric approach necessitating high quality visuals and real-time time-domain simulation. This survey reviews publications, commercial software and simulators, and regulations on offshore operations. Findings indicate that the VPOO is not common in the industry, offshore operation regulations lag behind the state of the art in industry in terms of mission planning, and this field has been subject to scarce commercial and scientific scrutiny so far. A discussion of future developments and trends concludes the paper.
{"title":"Virtual prototyping of offshore operations: a review","authors":"P. Major, Houxiang Zhang, Hans Petter Hildre, Mathieu Edet","doi":"10.1080/09377255.2020.1831840","DOIUrl":"https://doi.org/10.1080/09377255.2020.1831840","url":null,"abstract":"ABSTRACT Virtual prototyping of offshore operations (VPOO) is performed to plan and validate planning of infrequent or demanding operations characterized by high risk and low margins of error in hostile and remote environments distant from emergency response bases that require expensive equipment. Key elements of VPOO is the rapidity of virtual prototyping and the human-centric approach necessitating high quality visuals and real-time time-domain simulation. This survey reviews publications, commercial software and simulators, and regulations on offshore operations. Findings indicate that the VPOO is not common in the industry, offshore operation regulations lag behind the state of the art in industry in terms of mission planning, and this field has been subject to scarce commercial and scientific scrutiny so far. A discussion of future developments and trends concludes the paper.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1831840","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48510241","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 : 2020-10-07DOI: 10.1080/09377255.2020.1836552
Angus Gray-Stephens, T. Tezdogan, S. Day
ABSTRACT This study details an extensive investigation into the nearfield longitudinal wake profiles of a high-speed planing hull. Developing understanding this flow is benaficial to the designers of stepped hulls in determining how the forebody’s wake intersects with the afterbody. As no experimental data was available, a novel small-scale model-testing programme was undertaken, measuring Centreline (CL) and Quarter Beam (QB) nearfield longitudinal wake profiles, as well as the forces. The nearfield wake profile was found to exhibit trends in agreement with the findings of studies investigating the mid and far-field wake. The results of this experimental work are provided in full as validation data. Savitsky’s Wake Equations and the Linear Wake Assumption are then assessed to determine the level of confidence with which they may be used to model this flow. Savitsky’s Wake Equations displayed a surprising level of accuracy whereas the Linear Wake Assumption was invalid for the conditions investigated.
{"title":"Experimental measurement of the nearfield longitudinal wake profiles of a high-speed prismatic planing hull","authors":"Angus Gray-Stephens, T. Tezdogan, S. Day","doi":"10.1080/09377255.2020.1836552","DOIUrl":"https://doi.org/10.1080/09377255.2020.1836552","url":null,"abstract":"ABSTRACT This study details an extensive investigation into the nearfield longitudinal wake profiles of a high-speed planing hull. Developing understanding this flow is benaficial to the designers of stepped hulls in determining how the forebody’s wake intersects with the afterbody. As no experimental data was available, a novel small-scale model-testing programme was undertaken, measuring Centreline (CL) and Quarter Beam (QB) nearfield longitudinal wake profiles, as well as the forces. The nearfield wake profile was found to exhibit trends in agreement with the findings of studies investigating the mid and far-field wake. The results of this experimental work are provided in full as validation data. Savitsky’s Wake Equations and the Linear Wake Assumption are then assessed to determine the level of confidence with which they may be used to model this flow. Savitsky’s Wake Equations displayed a surprising level of accuracy whereas the Linear Wake Assumption was invalid for the conditions investigated.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1836552","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46911815","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 : 2020-09-02DOI: 10.1080/09377255.2020.1808759
A. Betge, A. Cura Hochbaum, E. Weitendorf
ABSTRACT Cavitation test results of identical bodies obtained in different cavitation tunnels sometimes differ from each other. One main reason for this is the influence of gas and nuclei content in the water. The knowledge of the water quality in the tunnel is crucial for comparing different results and for transferring them to full scale. Holography is a very promising optical technique for the measurement of cavitation nuclei, not least because of its accuracy, reliability, and repeatability at relatively low costs for its setup. First inline holography measurements have been performed at the cavitation tunnel K27 of TU Berlin with a preliminary setup. The K27 has a free water surface and therefore a high degassing behaviour. Selected measurements have been analysed and their results are shown here. Possible improvements for the test setup are considered. An inline digital holography configuration with laser and camera inside of the test section seems promising.
{"title":"Measurement of nuclei content by digital holography in a free surface cavitation tunnel","authors":"A. Betge, A. Cura Hochbaum, E. Weitendorf","doi":"10.1080/09377255.2020.1808759","DOIUrl":"https://doi.org/10.1080/09377255.2020.1808759","url":null,"abstract":"ABSTRACT Cavitation test results of identical bodies obtained in different cavitation tunnels sometimes differ from each other. One main reason for this is the influence of gas and nuclei content in the water. The knowledge of the water quality in the tunnel is crucial for comparing different results and for transferring them to full scale. Holography is a very promising optical technique for the measurement of cavitation nuclei, not least because of its accuracy, reliability, and repeatability at relatively low costs for its setup. First inline holography measurements have been performed at the cavitation tunnel K27 of TU Berlin with a preliminary setup. The K27 has a free water surface and therefore a high degassing behaviour. Selected measurements have been analysed and their results are shown here. Possible improvements for the test setup are considered. An inline digital holography configuration with laser and camera inside of the test section seems promising.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1808759","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48810333","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 : 2020-08-06DOI: 10.1080/09377255.2020.1802165
Malte Mittendorf, A. Papanikolaou
ABSTRACT This paper demonstrates the practical benefit of using efficient computational methods to optimize fast catamarans hydrodynamically. The development of a simplified panel method, which is based on thin ship theory, and the validation of the associated code for the prediction of the calm water resistance of twin-hull vessels is presented. The method was applied in the multi-objective optimization of a fast, zero-emission, battery-driven catamaran by a genetic algorithm, while considering the ensuing design constraints. Results of the study were compared with resistance predictions from a non-linear Rankine panel method and a viscous CFD solver. Moreover, surrogate models were implemented to speed up the optimization process involving several hundred parametrically generated designs. The proposed simplified panel method in connection with a empirical correction for the stern flow proved very valuable in the resistance prediction and hull form optimization of fast catamarans and of slender hulls in general.
{"title":"Hydrodynamic hull form optimization of fast catamarans using surrogate models","authors":"Malte Mittendorf, A. Papanikolaou","doi":"10.1080/09377255.2020.1802165","DOIUrl":"https://doi.org/10.1080/09377255.2020.1802165","url":null,"abstract":"ABSTRACT This paper demonstrates the practical benefit of using efficient computational methods to optimize fast catamarans hydrodynamically. The development of a simplified panel method, which is based on thin ship theory, and the validation of the associated code for the prediction of the calm water resistance of twin-hull vessels is presented. The method was applied in the multi-objective optimization of a fast, zero-emission, battery-driven catamaran by a genetic algorithm, while considering the ensuing design constraints. Results of the study were compared with resistance predictions from a non-linear Rankine panel method and a viscous CFD solver. Moreover, surrogate models were implemented to speed up the optimization process involving several hundred parametrically generated designs. The proposed simplified panel method in connection with a empirical correction for the stern flow proved very valuable in the resistance prediction and hull form optimization of fast catamarans and of slender hulls in general.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1802165","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49595624","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 : 2020-07-27DOI: 10.1080/09377255.2020.1798060
M. Andrun, B. Blagojević, J. Bašić, B. Klarin
ABSTRACT This article discusses numerical prediction of ventilated flows around the surface-piercing hydrofoil. A ventilated cavity is developed on the hydrofoil surface and the growth of the cavity is uncontrolled, which can have harmful effects as it leads to changes in the lift and unexpected loads. The occurrence of ventilation is computed by a Reynolds-Averaged Navier–Stokes solver based on the Finite Volume Method and the Volume of Fluid free surface capturing. The impact of numerical parameters on the ventilation is investigated by testing various momentum, gradient, and interface-capturing schemes, turbulence intesities, acceleration and time stepping scenarios, for 10 Froude numbers and 2 angles of attack. The analysis shows that simulations are consistent and comparable with the experimental data, if proper free surface capturing scheme and very low Courant numbers are used.
{"title":"Impact of CFD simulation parameters in prediction of ventilated flow on a surface-piercing hydrofoil","authors":"M. Andrun, B. Blagojević, J. Bašić, B. Klarin","doi":"10.1080/09377255.2020.1798060","DOIUrl":"https://doi.org/10.1080/09377255.2020.1798060","url":null,"abstract":"ABSTRACT This article discusses numerical prediction of ventilated flows around the surface-piercing hydrofoil. A ventilated cavity is developed on the hydrofoil surface and the growth of the cavity is uncontrolled, which can have harmful effects as it leads to changes in the lift and unexpected loads. The occurrence of ventilation is computed by a Reynolds-Averaged Navier–Stokes solver based on the Finite Volume Method and the Volume of Fluid free surface capturing. The impact of numerical parameters on the ventilation is investigated by testing various momentum, gradient, and interface-capturing schemes, turbulence intesities, acceleration and time stepping scenarios, for 10 Froude numbers and 2 angles of attack. The analysis shows that simulations are consistent and comparable with the experimental data, if proper free surface capturing scheme and very low Courant numbers are used.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1798060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49630336","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 : 2020-07-07DOI: 10.1080/09377255.2020.1786932
A. Bambulyak, S. Ehlers
ABSTRACT The global demand in energy resources is moving the petroleum industry to the Arctic with its huge resource potential. The lack of infrastructure onshore increases the role of the Arctic marine shipping and the importance of the Northern Sea Route (NSR). Shipping within NSR waters is associated with challenges and risks, including environmental ones, and may lead to high losses caused by an accidental oil spill. The present paper provides a description and the results from the application of a simulation model for selected tanker collision scenarios with an evaluation of possible oil spill sizes as result of discharge time, penetration depth, energy and force applied. NSR navigation data from 2013, the year with the record number of transits through NSR, were studied. These were used to generate probable oil spill scenarios caused by tanker collision, and financial liabilities for environmental damage were calculated using existing international and Russian methods.
{"title":"Oil spill damage: a collision scenario and financial liability estimations for the Northern Sea Route area","authors":"A. Bambulyak, S. Ehlers","doi":"10.1080/09377255.2020.1786932","DOIUrl":"https://doi.org/10.1080/09377255.2020.1786932","url":null,"abstract":"ABSTRACT The global demand in energy resources is moving the petroleum industry to the Arctic with its huge resource potential. The lack of infrastructure onshore increases the role of the Arctic marine shipping and the importance of the Northern Sea Route (NSR). Shipping within NSR waters is associated with challenges and risks, including environmental ones, and may lead to high losses caused by an accidental oil spill. The present paper provides a description and the results from the application of a simulation model for selected tanker collision scenarios with an evaluation of possible oil spill sizes as result of discharge time, penetration depth, energy and force applied. NSR navigation data from 2013, the year with the record number of transits through NSR, were studied. These were used to generate probable oil spill scenarios caused by tanker collision, and financial liabilities for environmental damage were calculated using existing international and Russian methods.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1786932","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48326100","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 : 2020-06-16DOI: 10.1080/09377255.2020.1780717
Shukui Liu
ABSTRACT This study reviews alternative analytical methods accounting for the influence of ship’s finite draft on the drift force due to diffraction effect. In very short waves, the wave is completed reflected and no wave energy can be transmitted under the ship. As the wave becomes longer, however, only part of the wave will be reflected and the remainder transmitted. The reflected waves will induce drift force due to its interaction with the ship between free surface and draft. The former effect can be quantified by the reflection coefficient, while the latter can be account for by introducing the draft based exponential function ( ). When both effects are accounted for, a unified and theoretically more complete formulation results. The performance of the method is demonstrated by comparative results for a vertical plate of finite draft and a standard ship.
{"title":"Revisiting the influence of a ship’s draft on the drift force due to diffraction effect","authors":"Shukui Liu","doi":"10.1080/09377255.2020.1780717","DOIUrl":"https://doi.org/10.1080/09377255.2020.1780717","url":null,"abstract":"ABSTRACT This study reviews alternative analytical methods accounting for the influence of ship’s finite draft on the drift force due to diffraction effect. In very short waves, the wave is completed reflected and no wave energy can be transmitted under the ship. As the wave becomes longer, however, only part of the wave will be reflected and the remainder transmitted. The reflected waves will induce drift force due to its interaction with the ship between free surface and draft. The former effect can be quantified by the reflection coefficient, while the latter can be account for by introducing the draft based exponential function ( ). When both effects are accounted for, a unified and theoretically more complete formulation results. The performance of the method is demonstrated by comparative results for a vertical plate of finite draft and a standard ship.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1780717","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48663335","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 : 2020-06-12DOI: 10.1080/09377255.2020.1759849
H. Yasukawa, Tsujimoto Masaru
ABSTRACT Resistance tests were conducted in regular and irregular head waves to study the impact of the bow shape on the added resistance of a full hull ship with block coefficient . The study used three different ship models with identical stern forms but systematically altered bow shapes. It was observed that a vertical stem without a protruding bow could help in reducing the added resistance in waves. The reduction ratio was about under both full and ballast loading conditions compared to a normal stem with a protruding bow. The strip method, known as the NMRI method, is applied in addition to the above- mentioned tests to predict the added resistances affecting the ships in regular waves and to clarify the effectiveness and range of application of the method. The NMRI method can qualitatively capture the differences in the added resistances in the bow shape series for a full hull ship. However, the calculations become less accurate under ballast loading condition.
{"title":"Impact of bow shape on added resistance of a full hull ship in head waves","authors":"H. Yasukawa, Tsujimoto Masaru","doi":"10.1080/09377255.2020.1759849","DOIUrl":"https://doi.org/10.1080/09377255.2020.1759849","url":null,"abstract":"ABSTRACT Resistance tests were conducted in regular and irregular head waves to study the impact of the bow shape on the added resistance of a full hull ship with block coefficient . The study used three different ship models with identical stern forms but systematically altered bow shapes. It was observed that a vertical stem without a protruding bow could help in reducing the added resistance in waves. The reduction ratio was about under both full and ballast loading conditions compared to a normal stem with a protruding bow. The strip method, known as the NMRI method, is applied in addition to the above- mentioned tests to predict the added resistances affecting the ships in regular waves and to clarify the effectiveness and range of application of the method. The NMRI method can qualitatively capture the differences in the added resistances in the bow shape series for a full hull ship. However, the calculations become less accurate under ballast loading condition.","PeriodicalId":51883,"journal":{"name":"Ship Technology Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2020-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09377255.2020.1759849","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43732529","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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