Pub Date : 2015-06-30DOI: 10.3329/JNAME.V12I1.21759
N. Hadžić, Marko Tomić, N. Vladimir, S. Ostojić, I. Senjanović
Shipbuilding is one of the most important manufacturing industries in Croatia involved in ships and offshore units’ production, maintenance, repair and installation with a significant impact on Croatian economy and society. Current state of the Croatian shipbuilding industry is presented herein, based on the most recent available data on global and domestic shipbuilding activities and important conclusions and recommendations for its future development are drawn considering current state of the world shipping and shipbuilding databases. Future perspectives are addressed through analysis of current negotiation potential of suppliers and buyers as well as with respect to the rivalry among competitors. An importance of stable financial background and development of the domestic industrial surroundings is pointed out. Along with that, current Croatian industrial 2020 strategy is addressed in order to enhance its application within the existing shipbuilding infrastructure as well as within Croatian economy. Finally, energy, food and entertainment market sectors are pointed out as the most perspective sectors capable of influencing future Croatian society, economy, science and technology.
{"title":"Current state and perspectives of the Croatian shipbuilding industry","authors":"N. Hadžić, Marko Tomić, N. Vladimir, S. Ostojić, I. Senjanović","doi":"10.3329/JNAME.V12I1.21759","DOIUrl":"https://doi.org/10.3329/JNAME.V12I1.21759","url":null,"abstract":"Shipbuilding is one of the most important manufacturing industries in Croatia involved in ships and offshore units’ production, maintenance, repair and installation with a significant impact on Croatian economy and society. Current state of the Croatian shipbuilding industry is presented herein, based on the most recent available data on global and domestic shipbuilding activities and important conclusions and recommendations for its future development are drawn considering current state of the world shipping and shipbuilding databases. Future perspectives are addressed through analysis of current negotiation potential of suppliers and buyers as well as with respect to the rivalry among competitors. An importance of stable financial background and development of the domestic industrial surroundings is pointed out. Along with that, current Croatian industrial 2020 strategy is addressed in order to enhance its application within the existing shipbuilding infrastructure as well as within Croatian economy. Finally, energy, food and entertainment market sectors are pointed out as the most perspective sectors capable of influencing future Croatian society, economy, science and technology.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"12 1","pages":"33-42"},"PeriodicalIF":1.8,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I1.21759","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514850","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 : 2015-06-30DOI: 10.3329/JNAME.V12I1.20450
S. Sunaryo, Dovan Pahalatua
The life cycle of a ship has an age limit related to its operation. When the ship economically is not profitable any more, it will be recycled or scrapped. Since the scrapped ship has plenty of hazardous materials, special care should be carried out to manage the wastes in accordance with the national and international available regulations. With regard to this a ship recycle yard that conducts ship breaking and recycle of the ship’s outfits, machineries, and infrastructure should be well designed in order to comply to all regulations that prevent it from producing harmful and polluting wastes to human and environment. The study was aimed to design an environmentally friendly or green ship recycle yard in Indonesia as a pilot project in anticipation to the booming of old used merchant ships fleet due to the implementation of cabotage principle. The project is located in the Maritime Industrial Cluster in Tanggamus Regency, Lampung Province, Sumatera. The ship recycle yard is designed with a capacity of maximum 30,000 DWT ship to be recycled, and all the activities involve in the yard would comply and refer to the environmental and IMO regulations, to ensure that no harm and hazardous wastes polluting the surrounding land and sea by arranging a proper layout and providing proper facilities and working procedures.
{"title":"GREEN SHIP RECYCLE YARD DESIGN","authors":"S. Sunaryo, Dovan Pahalatua","doi":"10.3329/JNAME.V12I1.20450","DOIUrl":"https://doi.org/10.3329/JNAME.V12I1.20450","url":null,"abstract":"The life cycle of a ship has an age limit related to its operation. When the ship economically is not profitable any more, it will be recycled or scrapped. Since the scrapped ship has plenty of hazardous materials, special care should be carried out to manage the wastes in accordance with the national and international available regulations. With regard to this a ship recycle yard that conducts ship breaking and recycle of the ship’s outfits, machineries, and infrastructure should be well designed in order to comply to all regulations that prevent it from producing harmful and polluting wastes to human and environment. The study was aimed to design an environmentally friendly or green ship recycle yard in Indonesia as a pilot project in anticipation to the booming of old used merchant ships fleet due to the implementation of cabotage principle. The project is located in the Maritime Industrial Cluster in Tanggamus Regency, Lampung Province, Sumatera. The ship recycle yard is designed with a capacity of maximum 30,000 DWT ship to be recycled, and all the activities involve in the yard would comply and refer to the environmental and IMO regulations, to ensure that no harm and hazardous wastes polluting the surrounding land and sea by arranging a proper layout and providing proper facilities and working procedures.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"12 1","pages":"15-20"},"PeriodicalIF":1.8,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I1.20450","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514670","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 : 2014-12-31DOI: 10.3329/JNAME.V11I2.6477
A. M. Okedoye
This paper to study unsteady MHD mixed convection flow past an infinite vertical oscillating plate through porous medium, taking account of the presence of free/forced convection and mass transfer. Using similarity transformation, the coupled non – linear governing equations are solved numerically by applying the combination of the base scheme submethods – midpoint, and a method enhancement scheme Richardson extrapolation technique together with Fehlberg fourth-fifth order Runge-Kutta shooting iteration method with degree four interpolant. The results are obtained for velocity, temperature, concentration. The effects of various material parameters are discussed on flow variables and presented by graphs. DOI: http://dx.doi.org/10.3329/jname.v11i2.6477
{"title":"Unsteady MHD mixed convection flow past an oscillating plate with heat source/sink","authors":"A. M. Okedoye","doi":"10.3329/JNAME.V11I2.6477","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.6477","url":null,"abstract":"This paper to study unsteady MHD mixed convection flow past an infinite vertical oscillating plate through porous medium, taking account of the presence of free/forced convection and mass transfer. Using similarity transformation, the coupled non – linear governing equations are solved numerically by applying the combination of the base scheme submethods – midpoint, and a method enhancement scheme Richardson extrapolation technique together with Fehlberg fourth-fifth order Runge-Kutta shooting iteration method with degree four interpolant. The results are obtained for velocity, temperature, concentration. The effects of various material parameters are discussed on flow variables and presented by graphs. DOI: http://dx.doi.org/10.3329/jname.v11i2.6477","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"23 1","pages":"167-176"},"PeriodicalIF":1.8,"publicationDate":"2014-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.6477","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514460","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 : 2014-12-24DOI: 10.3329/JNAME.V11I2.18420
S. Chandrasekaran, D. C. Raphel, S. Shree
Deep water offshore structures have access to very powerful ocean waves by virtue of their location and site condition. Should the energy possessed by these waves be harnessed, it can be one of the popular green energy systems. Present study aims at the design and development of a new device that can be fitted on an offshore semisubmersible platform and can produce electricity to meet their operational energy demands partially. Few wave energy devices are developed in the recent past; Common idea in all such devices is that they harness heave, or surge energy of the wave. In the present study, heave energy of the buoy is converted to mechanical work by deploying hydraulic cylinders and a motor. The generated power from the waves shall be primarily utilized in the semi-submersible platform for deep sea mining application. DOI: http://dx.doi.org/10.3329/jname.v11i2.18420
{"title":"Deep ocean wave energy systems (DOWES): experimental investigations","authors":"S. Chandrasekaran, D. C. Raphel, S. Shree","doi":"10.3329/JNAME.V11I2.18420","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.18420","url":null,"abstract":"Deep water offshore structures have access to very powerful ocean waves by virtue of their location and site condition. Should the energy possessed by these waves be harnessed, it can be one of the popular green energy systems. Present study aims at the design and development of a new device that can be fitted on an offshore semisubmersible platform and can produce electricity to meet their operational energy demands partially. Few wave energy devices are developed in the recent past; Common idea in all such devices is that they harness heave, or surge energy of the wave. In the present study, heave energy of the buoy is converted to mechanical work by deploying hydraulic cylinders and a motor. The generated power from the waves shall be primarily utilized in the semi-submersible platform for deep sea mining application. DOI: http://dx.doi.org/10.3329/jname.v11i2.18420","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"11 1","pages":"139-146"},"PeriodicalIF":1.8,"publicationDate":"2014-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.18420","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514740","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 : 2014-12-24DOI: 10.3329/JNAME.V11I2.18313
Venkata Ramana Reddy Gurrampati, S. Ibrahim, V. Bhagavan
This paper concerns with a steady two-dimensional flow of an electrically conducting incompressible dissipating fluid over an inclined semi-infinite porous surface with heat and mass transfer in presence of chemical reaction. The flow is permeated by a uniform transverse magnetic field. A scaling group of transformations is applied to the governing equations. The system remains invariant due to some relations among the parameters of the transformations. After finding three absolute invariants, a third-order ordinary differential equation corresponding to the momentum equation, and two second-order ordinary differential equations corresponding to energy and diffusion equations are derived. The coupled ordinary differential equations along with the boundary conditions are solved numerically. The effects of various parameters on velocity, temperature and concentration fields as well as skin-friction, Nusselt number and Sherwood number are presented graphically and in tabulated form. DOI: http://dx.doi.org/10.3329/jname.v11i2.18313
{"title":"SIMILARITY TRANSFORMATIONS OF HEAT AND MASS TRANSFER EFFECTS ON STEADY MHD FREE CONVECTION DISSIPATIVE FLUID FLOW PAST AN INCLINED POROUS SURFACE WITH CHEMICAL REACTION","authors":"Venkata Ramana Reddy Gurrampati, S. Ibrahim, V. Bhagavan","doi":"10.3329/JNAME.V11I2.18313","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.18313","url":null,"abstract":"This paper concerns with a steady two-dimensional flow of an electrically conducting incompressible dissipating fluid over an inclined semi-infinite porous surface with heat and mass transfer in presence of chemical reaction. The flow is permeated by a uniform transverse magnetic field. A scaling group of transformations is applied to the governing equations. The system remains invariant due to some relations among the parameters of the transformations. After finding three absolute invariants, a third-order ordinary differential equation corresponding to the momentum equation, and two second-order ordinary differential equations corresponding to energy and diffusion equations are derived. The coupled ordinary differential equations along with the boundary conditions are solved numerically. The effects of various parameters on velocity, temperature and concentration fields as well as skin-friction, Nusselt number and Sherwood number are presented graphically and in tabulated form. DOI: http://dx.doi.org/10.3329/jname.v11i2.18313","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"11 1","pages":"157-166"},"PeriodicalIF":1.8,"publicationDate":"2014-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.18313","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514661","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 : 2014-12-21DOI: 10.3329/JNAME.V11I2.17563
M. C. Raju, S. Varma
The problem of unsteady MHD free convective, incompressible electrically conducting, non-Newtonian fluid through porous medium bounded by an infinite porous plate in the presence of constant suction has been studied. A magnetic field of uniform strength is assumed to be applied normal to the plate. The equations governing the fluid flow which are highly nonlinear are reduced to linear by using perturbation method and have been solved subject to the relevant boundary conditions. It is noted that the velocity of the fluid is increased as Soret number and suction parameter increase, whereas reverse phenomenon is observed in case of magnetic field strength and sink strength. DOI: http://dx.doi.org/10.3329/jname.v11i2.17563
{"title":"Soret effects due to natural convection in a non-Newtonian fluid flow in porous medium with heat and mass transfer","authors":"M. C. Raju, S. Varma","doi":"10.3329/JNAME.V11I2.17563","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.17563","url":null,"abstract":"The problem of unsteady MHD free convective, incompressible electrically conducting, non-Newtonian fluid through porous medium bounded by an infinite porous plate in the presence of constant suction has been studied. A magnetic field of uniform strength is assumed to be applied normal to the plate. The equations governing the fluid flow which are highly nonlinear are reduced to linear by using perturbation method and have been solved subject to the relevant boundary conditions. It is noted that the velocity of the fluid is increased as Soret number and suction parameter increase, whereas reverse phenomenon is observed in case of magnetic field strength and sink strength. DOI: http://dx.doi.org/10.3329/jname.v11i2.17563","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"11 1","pages":"147-156"},"PeriodicalIF":1.8,"publicationDate":"2014-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.17563","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514442","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 : 2014-12-21DOI: 10.3329/JNAME.V11I2.18724
P. Ghadimi, M. A. F. Chekab, A. Dashtimanesh
Water impact phenomenon of general bow section is a critical event for planning hulls. In this paper, the water entry of several arbitrary bow sections is investigated. For this purpose, arbitrary bow shapes which are introduced by Lewis form approximation are considered. In order to obtain pressure distribution and free surface profile, volume of fluid (VOF) method coupled with finite volume method (FVM) are utilized in Ansys-CFX solver. The main feature of present study is consideration of some new arbitrary bow sections which have not been previously studied. Another motivation of the current work is investigation of water entry of arbitrary bow sections using a coupled numerical solution of FVM/VOF. Pressure distribution, free surface, and evolution of intersection point on bow sections are presented, while secondary water impact is demonstrated. Comparison of selected current findings against the results of previous studies indicates favorable agreement. DOI: http://dx.doi.org/10.3329/jname.v11i2.18724
{"title":"NUMERICAL SIMULATION OF WATER ENTRY OF DIFFERENT ARBITRARY BOW SECTIONS","authors":"P. Ghadimi, M. A. F. Chekab, A. Dashtimanesh","doi":"10.3329/JNAME.V11I2.18724","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.18724","url":null,"abstract":"Water impact phenomenon of general bow section is a critical event for planning hulls. In this paper, the water entry of several arbitrary bow sections is investigated. For this purpose, arbitrary bow shapes which are introduced by Lewis form approximation are considered. In order to obtain pressure distribution and free surface profile, volume of fluid (VOF) method coupled with finite volume method (FVM) are utilized in Ansys-CFX solver. The main feature of present study is consideration of some new arbitrary bow sections which have not been previously studied. Another motivation of the current work is investigation of water entry of arbitrary bow sections using a coupled numerical solution of FVM/VOF. Pressure distribution, free surface, and evolution of intersection point on bow sections are presented, while secondary water impact is demonstrated. Comparison of selected current findings against the results of previous studies indicates favorable agreement. DOI: http://dx.doi.org/10.3329/jname.v11i2.18724","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"11 1","pages":"117-129"},"PeriodicalIF":1.8,"publicationDate":"2014-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.18724","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514776","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 : 2014-12-19DOI: 10.3329/JNAME.V11I2.19167
N. Agarwala, E. M. D. Nair
When designing a floating airport we need to address the structural response both by ocean waves and dynamic loads such as the landing / take off of an airplane. Since such problems are not conducive to physical modeling and experimental validation due to their size and speeds involved, numerical analysis is an accepted norm. However conventional means to study structural responses using a three dimensional runway with time varying dynamic loads is numerically difficult and time consuming. The analysis is made simpler by assuming the airport to be a simple, infinitely long beam, given by a one dimensional Timoshenko-Mindlin plate equation, in contact with the water surface. In developing this expression, a Fourier transformation in space in wave number domain is utilized rather than using the wave propagation method to reduce the analysis to a substructure. On analyzing, the structural response is seen as local peaks emanating from the point of load application which moves in a curvilinear path with increasing speed of the airplane. The location of these peaks a priori is however not feasible. DOI: http://dx.doi.org/10.3329/jname.v11i2.19167
{"title":"Structural response of a floating runway excited by the taking off of an airplane","authors":"N. Agarwala, E. M. D. Nair","doi":"10.3329/JNAME.V11I2.19167","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.19167","url":null,"abstract":"When designing a floating airport we need to address the structural response both by ocean waves and dynamic loads such as the landing / take off of an airplane. Since such problems are not conducive to physical modeling and experimental validation due to their size and speeds involved, numerical analysis is an accepted norm. However conventional means to study structural responses using a three dimensional runway with time varying dynamic loads is numerically difficult and time consuming. The analysis is made simpler by assuming the airport to be a simple, infinitely long beam, given by a one dimensional Timoshenko-Mindlin plate equation, in contact with the water surface. In developing this expression, a Fourier transformation in space in wave number domain is utilized rather than using the wave propagation method to reduce the analysis to a substructure. On analyzing, the structural response is seen as local peaks emanating from the point of load application which moves in a curvilinear path with increasing speed of the airplane. The location of these peaks a priori is however not feasible. DOI: http://dx.doi.org/10.3329/jname.v11i2.19167","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"11 1","pages":"131-138"},"PeriodicalIF":1.8,"publicationDate":"2014-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.19167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514864","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 : 2014-12-18DOI: 10.3329/JNAME.V11I2.17341
D. S. B. Rao, R. Selvam, N. Srinivasan
Tension Leg Platforms (TLPs) are one of the reliable structures for offshore industry in deep waters because of its motion characteristics in heave, roll and pitch degrees of freedom. Heave motion is very important in offshore facilities and have to kept as minimum as possible. As the water depth increases TLPs suffers from some limitations and hence has to be modified to cater to deeper waters. One such concept proposed is Tension Based Tension Leg Platform (TBTLP). In this paper, experimental investigations carried out on a scaled model of a Tension Based Tension Leg Platform in regular waves are reported. This is the first ever experiments that was carried out on a scaled model of the new concept. To investigate the effect of Tension Base, experiments were also conducted on the TLP (without Tension Base) in two different water depths. RAOs have been compared for surge and heave dof of TLP and TBTLP. Numerical modeling of the TLP and TBTLP responses using ANSYS AQWA software are included as well for comparisons. DOI: http://dx.doi.org/10.3329/jname.v11i2.17341
{"title":"EXPERIMENTAL INVESTIGATIONS ON TENSION BASED TENSION LEG PLATFORM (TBTLP)","authors":"D. S. B. Rao, R. Selvam, N. Srinivasan","doi":"10.3329/JNAME.V11I2.17341","DOIUrl":"https://doi.org/10.3329/JNAME.V11I2.17341","url":null,"abstract":"Tension Leg Platforms (TLPs) are one of the reliable structures for offshore industry in deep waters because of its motion characteristics in heave, roll and pitch degrees of freedom. Heave motion is very important in offshore facilities and have to kept as minimum as possible. As the water depth increases TLPs suffers from some limitations and hence has to be modified to cater to deeper waters. One such concept proposed is Tension Based Tension Leg Platform (TBTLP). In this paper, experimental investigations carried out on a scaled model of a Tension Based Tension Leg Platform in regular waves are reported. This is the first ever experiments that was carried out on a scaled model of the new concept. To investigate the effect of Tension Base, experiments were also conducted on the TLP (without Tension Base) in two different water depths. RAOs have been compared for surge and heave dof of TLP and TBTLP. Numerical modeling of the TLP and TBTLP responses using ANSYS AQWA software are included as well for comparisons. DOI: http://dx.doi.org/10.3329/jname.v11i2.17341","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"6 1","pages":"105-116"},"PeriodicalIF":1.8,"publicationDate":"2014-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V11I2.17341","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69513853","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 : 2014-06-25DOI: 10.3329/JNAME.V11I1.16725
S. Zahir
This contribution presents a computational simulation for a generic hull shape with attached short pin-protuberance for its hydrodynamic characteristics. This work is a part of a large framework of numerical simulation and experimentation carried out for blunted head-forms of hemispheric shapes for determination of aero-hydrodynamic coefficients and static stability features. Results are presented for a clean hull-form and with the pin-protuberance, as static axial and circumferential pressure distribution on the surface, calculated at a fixed velocity and at different angle of attacks, under non-cavitating depth and velocity. It is shown that a suitably located short lateral pin has an adequate effectiveness to control pitch maneuver of an underwater hemisphere-cylinder hull-form. In view of that, a suitable pin-height adjustment commensurate to pitch attitude trajectory corrections is a workable idea, and the concept has potential of effective pitch attitude control of the hemisphere-cylinder hull-form. DOI: http://dx.doi.org/10.3329/jname.v11i1.16725
{"title":"Computational hydrodynamic simulations for an underwater axisymmetric hemisphere-cylinder hull-form at incidence","authors":"S. Zahir","doi":"10.3329/JNAME.V11I1.16725","DOIUrl":"https://doi.org/10.3329/JNAME.V11I1.16725","url":null,"abstract":"This contribution presents a computational simulation for a generic hull shape with attached short pin-protuberance for its hydrodynamic characteristics. This work is a part of a large framework of numerical simulation and experimentation carried out for blunted head-forms of hemispheric shapes for determination of aero-hydrodynamic coefficients and static stability features. Results are presented for a clean hull-form and with the pin-protuberance, as static axial and circumferential pressure distribution on the surface, calculated at a fixed velocity and at different angle of attacks, under non-cavitating depth and velocity. It is shown that a suitably located short lateral pin has an adequate effectiveness to control pitch maneuver of an underwater hemisphere-cylinder hull-form. In view of that, a suitable pin-height adjustment commensurate to pitch attitude trajectory corrections is a workable idea, and the concept has potential of effective pitch attitude control of the hemisphere-cylinder hull-form. DOI: http://dx.doi.org/10.3329/jname.v11i1.16725","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":"11 1","pages":"93-104"},"PeriodicalIF":1.8,"publicationDate":"2014-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69513453","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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