Pub Date : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.81
R. Jang, Y. Higo
When the seabed is vibrating due to earthquake, not only the compression waves in seawater but also the free surface waves occur at the same time and these interact with each other. In this paper, the wave elevations on free surface interacted with compression waves caused by earthquake is numerically studied. A kernel function satisfying the wave equation in compression wave field is introduced and the free surface elevations which satisfy the free surface boundary condition in three dimensional time domain are calculated by making use of the boundary integral equation method. Through the calculations, the relations between frequencies of vibrating seabed and the free surface waves are made clear. Furthermore, when there is a fixed floating body in the considered region, the effect on the free surface elevations is studied.
{"title":"Free surface wave elevation interacted with compression waves in seawater caused by earthquake","authors":"R. Jang, Y. Higo","doi":"10.2534/JJASNAOE1968.2001.81","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.81","url":null,"abstract":"When the seabed is vibrating due to earthquake, not only the compression waves in seawater but also the free surface waves occur at the same time and these interact with each other. In this paper, the wave elevations on free surface interacted with compression waves caused by earthquake is numerically studied. A kernel function satisfying the wave equation in compression wave field is introduced and the free surface elevations which satisfy the free surface boundary condition in three dimensional time domain are calculated by making use of the boundary integral equation method. Through the calculations, the relations between frequencies of vibrating seabed and the free surface waves are made clear. Furthermore, when there is a fixed floating body in the considered region, the effect on the free surface elevations is studied.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115887985","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.291
K. Gotoh, M. Toyosada, Shoji Takechi
{"title":"A Practical Estimation Method of the Skin Plate Distortion Derived from Fillet Weld","authors":"K. Gotoh, M. Toyosada, Shoji Takechi","doi":"10.2534/JJASNAOE1968.2001.291","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.291","url":null,"abstract":"","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123285797","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.101
Kei Sato, Toru Sato
Air- and CO2-bubble plumes in stratification are studied by laboratory-scale experiments. These plume behavior is important in CO2 ocean sequestration or destruction of stratification using bubble plume. The relations of the depth of intrusion to the strength of stratification, the flow rate of bubbles, and the diameter of bubbles are investigated by using non-dimensional numbers. The results indicate a new tendency that the larger the bubble size becomes, the shallower the depth of intrusion. Also, our numerical simulation method for two-phase flow is validated by comparing with the experiments.
{"title":"An Experimental and Numerical Study on Bubble Plume Behavior in Stratification","authors":"Kei Sato, Toru Sato","doi":"10.2534/JJASNAOE1968.2001.101","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.101","url":null,"abstract":"Air- and CO2-bubble plumes in stratification are studied by laboratory-scale experiments. These plume behavior is important in CO2 ocean sequestration or destruction of stratification using bubble plume. The relations of the depth of intrusion to the strength of stratification, the flow rate of bubbles, and the diameter of bubbles are investigated by using non-dimensional numbers. The results indicate a new tendency that the larger the bubble size becomes, the shallower the depth of intrusion. Also, our numerical simulation method for two-phase flow is validated by comparing with the experiments.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134470958","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.31
B. Iskandar, N. Umeda, M. Hamamoto
In our first report, we presented a methodology for determining the critical metecentric height of an Indonesia RoRo passenger ship in the light of the annual capsizing probability calculated with piece-wise linear mathematical model and wave statistics. The second report follows the methodology in the first report, and provides more realistic outcomes by making use of the ship roll data from the model experiments and corrected wave statistics. As a result, it is demonstrated that the annual capsizing probability of the Indonesian RoRo passenger ship with side openings of the RoRo space almost coincides with the actual capsizing rate taken from the casualty statistics in Indonesian water areas, and can be drastically reduced by closing the side openings.
{"title":"Capsizing Probability of an Indonesian RoRo Passenger Ship in Irregular Beam Seas (Second Report)","authors":"B. Iskandar, N. Umeda, M. Hamamoto","doi":"10.2534/JJASNAOE1968.2001.31","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.31","url":null,"abstract":"In our first report, we presented a methodology for determining the critical metecentric height of an Indonesia RoRo passenger ship in the light of the annual capsizing probability calculated with piece-wise linear mathematical model and wave statistics. The second report follows the methodology in the first report, and provides more realistic outcomes by making use of the ship roll data from the model experiments and corrected wave statistics. As a result, it is demonstrated that the annual capsizing probability of the Indonesian RoRo passenger ship with side openings of the RoRo space almost coincides with the actual capsizing rate taken from the casualty statistics in Indonesian water areas, and can be drastically reduced by closing the side openings.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122028626","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.13
Jong-Chun Park, H. Miyata
The present paper describes the numerical estimation of maximum wave run-up and higher-harmonic forces on an Arctic and offshore structures using a Numerical Wave Tank (NWT) simulation technique. A finite-difference method and a modified marker-and-cell (MAC) algorithm are adopted to calculate wave forces and wave run-up on an Arctic and offshore structures of arbitrary shape, and to investigate the characteristics of nonlinear wave motions and their complexity of interactions with structures The Navier-Stokes (NS) and continuity equation are governed in the computational domain and the boundary values updated at each time step by a finite-difference time-marching scheme in the frame of rectangular coordinate system. The fully-nonlinear kinematic free-surface condition is satisfied by the marker-density function technique The results by NS-MAC NWT simulation for an Arctic structure are compared to the predictions of linear diffraction analysis, based on an integral equation method for vertical axisymmetric structures. For an offshore structure the simulated results are also compared with those of other numerical methods and measured data.
{"title":"Numerical Simulation of Fully-Nonlinear Wave Motions around Arctic and Offshore Structures","authors":"Jong-Chun Park, H. Miyata","doi":"10.2534/JJASNAOE1968.2001.13","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.13","url":null,"abstract":"The present paper describes the numerical estimation of maximum wave run-up and higher-harmonic forces on an Arctic and offshore structures using a Numerical Wave Tank (NWT) simulation technique. A finite-difference method and a modified marker-and-cell (MAC) algorithm are adopted to calculate wave forces and wave run-up on an Arctic and offshore structures of arbitrary shape, and to investigate the characteristics of nonlinear wave motions and their complexity of interactions with structures The Navier-Stokes (NS) and continuity equation are governed in the computational domain and the boundary values updated at each time step by a finite-difference time-marching scheme in the frame of rectangular coordinate system. The fully-nonlinear kinematic free-surface condition is satisfied by the marker-density function technique The results by NS-MAC NWT simulation for an Arctic structure are compared to the predictions of linear diffraction analysis, based on an integral equation method for vertical axisymmetric structures. For an offshore structure the simulated results are also compared with those of other numerical methods and measured data.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115098098","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.405
H. Kurokawa, Nobue Matsuura, S. Tsuruta, Tomikazu Kazama
The examinations of the modal shift to the marine transportation were carried out by many researchers. But, the multi-mode choice in the transportation was not sufficiently analyzed.So, we build the model of the multi-mode choice based on the freight rates and the time required. In this paper, the examination results of the modal shift to the marine transportation which used the modal-split model (minimum sacrifice model) are shown. The effect of the modal shift by the decrease of the freight rates and the shortening of the time required becomes clear. The difference of the effect by the classification of the cargo is also found out.
{"title":"An Examination about the Modal Shift to the Marine Transportation by the Modal Split Model","authors":"H. Kurokawa, Nobue Matsuura, S. Tsuruta, Tomikazu Kazama","doi":"10.2534/JJASNAOE1968.2001.405","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.405","url":null,"abstract":"The examinations of the modal shift to the marine transportation were carried out by many researchers. But, the multi-mode choice in the transportation was not sufficiently analyzed.So, we build the model of the multi-mode choice based on the freight rates and the time required. In this paper, the examination results of the modal shift to the marine transportation which used the modal-split model (minimum sacrifice model) are shown. The effect of the modal shift by the decrease of the freight rates and the shortening of the time required becomes clear. The difference of the effect by the classification of the cargo is also found out.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128832094","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.219
S. Nakasumi, Katsuyuki Suzuki, D. Fujii, H. Ohtsubo
This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate the effectiveness of the method.
{"title":"Mixed analysis of shell and solid elements using overlaying mesh method","authors":"S. Nakasumi, Katsuyuki Suzuki, D. Fujii, H. Ohtsubo","doi":"10.2534/JJASNAOE1968.2001.219","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.219","url":null,"abstract":"This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate the effectiveness of the method.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117276079","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.1
Erwandi, Toshio Suzuki
This paper is the second report that describes the capability of projected light distribution method to measure the diffraction waves generated by a ship operating in regular incident waves. In this method the waves are projected onto a screen as light distribution images and the images are recorded using a CCD Camera. In order to obtain diffraction waves, experiments were divided into two steps. Firstly, incident waves were measured. Secondly, the combination between incident waves with diffraction waves around a ship model was measured. The diffraction waves can then be obtained by subtracting incident wave images from combined one. The Kochin function was obtained using the same method as explained in the previous paper 6) . The results are evaluated by making some transverse cuts on the image data in the y-direction (transverse cut). The obtained Kochin functions are compared with the longitudinal cut results based on Ohkusu method, and also with theoretical results based on slender body theory. Using the results of Kochin Function, the wave pattern are recalculated and they are compared with the results of measurement using super sonic wave height meters.
{"title":"Analysis of Diffraction Waves Around a Ship Using Projected Light Distribution Method","authors":"Erwandi, Toshio Suzuki","doi":"10.2534/JJASNAOE1968.2001.1","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.1","url":null,"abstract":"This paper is the second report that describes the capability of projected light distribution method to measure the diffraction waves generated by a ship operating in regular incident waves. In this method the waves are projected onto a screen as light distribution images and the images are recorded using a CCD Camera. In order to obtain diffraction waves, experiments were divided into two steps. Firstly, incident waves were measured. Secondly, the combination between incident waves with diffraction waves around a ship model was measured. The diffraction waves can then be obtained by subtracting incident wave images from combined one. The Kochin function was obtained using the same method as explained in the previous paper 6) . The results are evaluated by making some transverse cuts on the image data in the y-direction (transverse cut). The obtained Kochin functions are compared with the longitudinal cut results based on Ohkusu method, and also with theoretical results based on slender body theory. Using the results of Kochin Function, the wave pattern are recalculated and they are compared with the results of measurement using super sonic wave height meters.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"539 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125785158","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.119
R. Jung, Toru Sato
A CFD code based on unstructured mesh consisting of tetrahedrons and triangular prisms has been developed. The prisms are generated along body boundaries to resolute momentum boundary layers. A cell-centered finite volume discretization, the fractional step algorithm, third order compact scheme for convection term, a central difference for the diffusion term are adopted. In high Schmidt number problems, mass boundary layer is much thinner than that of momentum so that very thin layers (VTL) are generated in one layer of prisms attached to the interface only for solving mass transfer. It is noted that the explicit time integration is used for momentum, while mass is solved implicitly in time for reducing computational time. The Sherwood numbers of a solid sphere are obtained in our numerical experiments and are in good agreement with some typical empirical equations.
{"title":"Very Thin Layer Method for Solving High Schmidt Number Flow on Unstructured Hybrid Mesh","authors":"R. Jung, Toru Sato","doi":"10.2534/JJASNAOE1968.2001.119","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.119","url":null,"abstract":"A CFD code based on unstructured mesh consisting of tetrahedrons and triangular prisms has been developed. The prisms are generated along body boundaries to resolute momentum boundary layers. A cell-centered finite volume discretization, the fractional step algorithm, third order compact scheme for convection term, a central difference for the diffusion term are adopted. In high Schmidt number problems, mass boundary layer is much thinner than that of momentum so that very thin layers (VTL) are generated in one layer of prisms attached to the interface only for solving mass transfer. It is noted that the explicit time integration is used for momentum, while mass is solved implicitly in time for reducing computational time. The Sherwood numbers of a solid sphere are obtained in our numerical experiments and are in good agreement with some typical empirical equations.","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122155680","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 : 2001-06-01DOI: 10.2534/JJASNAOE1968.2001.241
H. Yasukawa, M. Ozaki, E. Kogure, M. Ohashi, K. Ishida, Hiroaki Hirayama
{"title":"Dynamic Analysis of a Near Surface Disconnectable Drilling Riser","authors":"H. Yasukawa, M. Ozaki, E. Kogure, M. Ohashi, K. Ishida, Hiroaki Hirayama","doi":"10.2534/JJASNAOE1968.2001.241","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.2001.241","url":null,"abstract":"","PeriodicalId":321056,"journal":{"name":"Journal of the Society of Naval Architects of Japan","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125114762","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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