The marine environment represents a large and important resource for communities around the world. However, the marine environment increasingly presents hazards that can have a large negative impact. One important marine hazard results from storms and their accompanying surges. This can lead to coastal flooding, particularly when surge and astronomical high tides align, with resultant impacts such as destruction of property, saline degradation of agricultural land and coastal erosion. Where tide and storm surge information are provided and accessed in a timely, accurate and understandable way, the data can provide: 1. Evidence for planning: Statistics of past conditions such as the probability of extreme event occurrence can be used to help plan improvements to coastal infrastructure that are able to withstand and mitigate the hazard from a given extreme event. 2. Early warning systems: Short term forecasts of storm surge allow provide early warnings to coastal communities enabling them to take actions to allow them to withstand extreme events, e.g. deploy flood prevention measures or mobilise emergency response measures. Data regarding sea level height can be provided from various in-situ observations such as tide gauges and remote observations such as satellite altimetry. However, to provide a forecast at high spatial and temporal resolution a dynamic ocean model is used. Over recent decades the National Oceanography Centre has been a world leading in developing coastal ocean models. This paper will present our progress on a current project to develop an information system for the Madagascan Met Office. The project, C-RISC, being executed in partnership with Sea Level Research Ltd, is translating the current modelling capability of NOC in storm surge forecasting and tidal prediction into a system that will provide information that can be easily transferred to other regions and is scalable to include other hazard types The outcome, an operational high-resolution storm surge warning system that is easy to relocate, will directly benefit coastal communities, giving them information they need to make effective decisions before and during extreme storm surge events.
{"title":"Relocatable Tide Prediction and Storm Surge Forecasting","authors":"T. Prime","doi":"10.1115/OMAE2018-77926","DOIUrl":"https://doi.org/10.1115/OMAE2018-77926","url":null,"abstract":"The marine environment represents a large and important resource for communities around the world. However, the marine environment increasingly presents hazards that can have a large negative impact. One important marine hazard results from storms and their accompanying surges. This can lead to coastal flooding, particularly when surge and astronomical high tides align, with resultant impacts such as destruction of property, saline degradation of agricultural land and coastal erosion.\u0000 Where tide and storm surge information are provided and accessed in a timely, accurate and understandable way, the data can provide:\u0000 1. Evidence for planning: Statistics of past conditions such as the probability of extreme event occurrence can be used to help plan improvements to coastal infrastructure that are able to withstand and mitigate the hazard from a given extreme event.\u0000 2. Early warning systems: Short term forecasts of storm surge allow provide early warnings to coastal communities enabling them to take actions to allow them to withstand extreme events, e.g. deploy flood prevention measures or mobilise emergency response measures.\u0000 Data regarding sea level height can be provided from various in-situ observations such as tide gauges and remote observations such as satellite altimetry. However, to provide a forecast at high spatial and temporal resolution a dynamic ocean model is used. Over recent decades the National Oceanography Centre has been a world leading in developing coastal ocean models. This paper will present our progress on a current project to develop an information system for the Madagascan Met Office. The project, C-RISC, being executed in partnership with Sea Level Research Ltd, is translating the current modelling capability of NOC in storm surge forecasting and tidal prediction into a system that will provide information that can be easily transferred to other regions and is scalable to include other hazard types The outcome, an operational high-resolution storm surge warning system that is easy to relocate, will directly benefit coastal communities, giving them information they need to make effective decisions before and during extreme storm surge events.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124431355","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}
Marine structures are subjected to wave forces whether they are stationary or moving. Such wave forces play a significant role in the design and operation of marine structures. The aim of this study is to understand and predict the unsteady hydrodynamic loads experienced by a submerged body near the surface. Both numerical and experimental studies were conducted. For the experimental work, a newly constructed wave maker inside a tow tank was utilized while a computational fluid dynamics model was developed for the numerical study. Both experimental and numerical studies can complement each other. First, the computational model was validated against experimental wave data so as to understand what parameters in numerical modeling influence the reliability of the numerical results. The second aim was to understand the force and moment that a submerged body would experience for different wave lengths.
{"title":"Numerical and Experimental Study of Wave-Induced Load Effects on a Submerged Body Near the Surface","authors":"L. Jones, J. Klamo, Young W. Kwon, J. Didoszak","doi":"10.1115/OMAE2018-77624","DOIUrl":"https://doi.org/10.1115/OMAE2018-77624","url":null,"abstract":"Marine structures are subjected to wave forces whether they are stationary or moving. Such wave forces play a significant role in the design and operation of marine structures. The aim of this study is to understand and predict the unsteady hydrodynamic loads experienced by a submerged body near the surface. Both numerical and experimental studies were conducted. For the experimental work, a newly constructed wave maker inside a tow tank was utilized while a computational fluid dynamics model was developed for the numerical study. Both experimental and numerical studies can complement each other. First, the computational model was validated against experimental wave data so as to understand what parameters in numerical modeling influence the reliability of the numerical results. The second aim was to understand the force and moment that a submerged body would experience for different wave lengths.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131085063","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}
The need of continuously improving propulsive efficiency encourages the development of energy saving devices, the understanding of their underlying principles and the validation of their effectiveness. In this work, a design by optimization of Propeller Boss Cap Fin (PBCF) devices is carried out using Computational Fluid Dynamics analyses. RANS calculations (by the OpenFOAM library) are applied in an automatic optimization design approach involving a parametric description of the main characteristics of PBCFs. The optimization is carried out with multiple purposes: identify a reliable design strategy necessary to customize the PBCF geometry based on the propeller functioning and evaluate the influence of alternative configurations and of main geometrical parameters in achieving higher efficiency. The use of high-fidelity RANS calculations confirm that the decrease of the hub vortex strength, the reduction of the net torque and the influence of the additional fins on blades performance are the major contributors to the increase of efficiency. Results of detailed analyses of optimal PBCF configurations show model scale increases of efficiency of about 1%.
{"title":"An Optimization Framework for PBCF Energy Saving Devices","authors":"S. Gaggero, D. Villa","doi":"10.1115/OMAE2018-77921","DOIUrl":"https://doi.org/10.1115/OMAE2018-77921","url":null,"abstract":"The need of continuously improving propulsive efficiency encourages the development of energy saving devices, the understanding of their underlying principles and the validation of their effectiveness. In this work, a design by optimization of Propeller Boss Cap Fin (PBCF) devices is carried out using Computational Fluid Dynamics analyses. RANS calculations (by the OpenFOAM library) are applied in an automatic optimization design approach involving a parametric description of the main characteristics of PBCFs. The optimization is carried out with multiple purposes: identify a reliable design strategy necessary to customize the PBCF geometry based on the propeller functioning and evaluate the influence of alternative configurations and of main geometrical parameters in achieving higher efficiency. The use of high-fidelity RANS calculations confirm that the decrease of the hub vortex strength, the reduction of the net torque and the influence of the additional fins on blades performance are the major contributors to the increase of efficiency. Results of detailed analyses of optimal PBCF configurations show model scale increases of efficiency of about 1%.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124522749","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}
There has been speculation that energy input (wind) can play an important role in the formation of rogue waves in the open ocean. Here we examine the role energy input can play by adding energy to the modified non-linear Schrödinger equation. We consider NewWave type wave-groups with spectra which are realistic for wind waves. We examine the case where energy input is added to the group as the wave-group focuses. We consider whether this energy input can cause significant non-linear effects to the subsequent spatial and spectral evolution. For the parameters considered here we find this to have only a small influence.
{"title":"Ocean Wave Non-Linearity and Wind Input in Directional Seas: Energy Input During Wave-Group Focussing","authors":"T. Adcock, P. Taylor","doi":"10.1115/OMAE2018-77998","DOIUrl":"https://doi.org/10.1115/OMAE2018-77998","url":null,"abstract":"There has been speculation that energy input (wind) can play an important role in the formation of rogue waves in the open ocean. Here we examine the role energy input can play by adding energy to the modified non-linear Schrödinger equation. We consider NewWave type wave-groups with spectra which are realistic for wind waves. We examine the case where energy input is added to the group as the wave-group focuses. We consider whether this energy input can cause significant non-linear effects to the subsequent spatial and spectral evolution. For the parameters considered here we find this to have only a small influence.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"2011 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129755325","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}
In widely used metocean terminology, solitons are large amplitude, often highly nonlinear, internal waves. They are responsible for complex vertical profiles of rapidly varying ocean currents. These current profiles need to be reliably quantified for a wide range of offshore engineering applications, often with very limited suitable data. Some recent advances in this field of applied research were described at OMAE2017 by Jeans et al (2017) [1]. Vertical displacements, derived from temperature measurements, were the primary input for soliton quantification. Associated current speeds were estimated from relevant theory and validated using available measured current data. This represents a notable development, because soliton current profiles are traditionally quantified via direct measurements of velocity. However, reliable current measurements can be a challenge, so the new approach is considered more reliable in some circumstances. Jeans et al (2017) [1] applied one simple and elegant theory for relating vertical displacement to velocity. This theory performed well, considering its limitations. This paper further evaluates different theoretical options, using a new dataset with much larger amplitude solitons. Theories with higher order nonlinearity are required for estimation of soliton current profiles in such challenging conditions.
在广泛使用的海洋术语中，孤子是大振幅，通常是高度非线性的内波。它们负责快速变化的洋流的复杂垂直剖面。目前这些剖面需要可靠地量化，用于广泛的海上工程应用，通常只有非常有限的合适数据。Jeans et al(2017)[1]在OMAE2017上描述了该领域应用研究的一些最新进展。由温度测量得出的垂直位移是孤子量化的主要输入。根据相关理论估计相关电流速度，并使用现有的测量电流数据进行验证。这代表了一个显著的发展，因为传统上孤子电流剖面是通过直接测量速度来量化的。然而，可靠的电流测量可能是一个挑战，因此在某些情况下，新方法被认为更可靠。Jeans等人(2017)[1]应用了一个简单而优雅的理论来将垂直位移与速度联系起来。考虑到它的局限性，这个理论表现得很好。本文使用具有更大振幅孤子的新数据集进一步评估了不同的理论选择。在这种具有挑战性的条件下，需要具有高阶非线性的理论来估计孤子电流分布。
{"title":"The Quantification of Soliton Current Profiles for Offshore Engineering","authors":"G. Jeans, A. Osborne, C. Jackson","doi":"10.1115/OMAE2018-77863","DOIUrl":"https://doi.org/10.1115/OMAE2018-77863","url":null,"abstract":"In widely used metocean terminology, solitons are large amplitude, often highly nonlinear, internal waves. They are responsible for complex vertical profiles of rapidly varying ocean currents. These current profiles need to be reliably quantified for a wide range of offshore engineering applications, often with very limited suitable data.\u0000 Some recent advances in this field of applied research were described at OMAE2017 by Jeans et al (2017) [1]. Vertical displacements, derived from temperature measurements, were the primary input for soliton quantification. Associated current speeds were estimated from relevant theory and validated using available measured current data. This represents a notable development, because soliton current profiles are traditionally quantified via direct measurements of velocity. However, reliable current measurements can be a challenge, so the new approach is considered more reliable in some circumstances.\u0000 Jeans et al (2017) [1] applied one simple and elegant theory for relating vertical displacement to velocity. This theory performed well, considering its limitations. This paper further evaluates different theoretical options, using a new dataset with much larger amplitude solitons. Theories with higher order nonlinearity are required for estimation of soliton current profiles in such challenging conditions.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126632312","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}
This online compilation of papers from the ASME Turbo Expo 2014: Turbine Technical Conference and Exposition (GT2014) represents the archival version of the Conference Proceedings. According to ASME’s conference presenter attendance policy, if a paper is not presented at the Conference, the paper will not be published in the official archival Proceedings, which are registered with the Library of Congress and are submitted for abstracting and indexing. The paper also will not be published in The ASME Digital Collection and may not be cited as a published paper.
这篇来自ASME涡轮博览会2014:涡轮技术会议和博览会(GT2014)的在线论文汇编代表了会议论文集的档案版本。根据ASME会议主讲人出席政策，如果一篇论文没有在会议上发表，该论文将不会发表在美国国会图书馆注册的官方档案论文集上，并提交摘要和索引。该论文也不会在ASME Digital Collection上发表，也不能作为已发表论文被引用。
{"title":"ASME Conference Presenter Attendance Policy and Archival Proceedings","authors":"","doi":"10.1115/omae2018-ns7b","DOIUrl":"https://doi.org/10.1115/omae2018-ns7b","url":null,"abstract":"This online compilation of papers from the ASME Turbo Expo 2014: Turbine Technical Conference and Exposition (GT2014) represents the archival version of the Conference Proceedings. According to ASME’s conference presenter attendance policy, if a paper is not presented at the Conference, the paper will not be published in the official archival Proceedings, which are registered with the Library of Congress and are submitted for abstracting and indexing. The paper also will not be published in The ASME Digital Collection and may not be cited as a published paper.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133380926","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}
Typical offshore structures are designed as tension-leg platforms or gravity based structures with cylindrical substructures. The interaction of waves with the vertical cylinders in high sea states can result in a resonant response called ringing. Here, the frequency of the structural response is close to the natural frequency of the structure itself and leads to large amplitude motions. This is a case of extreme wave loading in high sea states. This understanding of higher-order wave forces in extreme sea states is an essential parameter for obtaining a safe, reliable and economical design of an offshore structure. The study of such higher-order effects needs detailed near-field modelling of the wave-structure interaction and the associated flow phenomena. In such cases, a Computational Fluid Dynamics (CFD) model that can accurately represent the free surface and further the wave-structure interaction problem can provide important insights into the wave hydrodynamics and the structural response. In this paper, the open source CFD model REEF3D is used to simulate wave interaction with a vertical cylinder and the wave forces on the cylinder are calculated. The harmonic components of the wave force are analysed. The model employs higher-order discretisation schemes such as a fifth-order WENO scheme for convection discretisation and a third-order Runge-Kutta scheme for time advancement on a staggered Cartesian grid. The level set method is used to obtain the free surface, providing a sharp interface between air and water. The relaxation method is used to generate and absorb the waves at the two ends of the numerical wave tank. This method provides good quality wave generation and also the wave reflected from the cylinder are absorbed at the wave generation zone. In this way, the generated waves are not affected by the wave interaction process in the numerical wave tank. This is very essential in the studies of higher-order wave interaction problems which are very sensitive to the incident wave characteristics. The numerical results are compared to experimental results for higher-order forces on a vertical cylinder to validate the numerical model.
{"title":"Investigation of Higher-Harmonic Wave Forces and Ringing Using CFD Simulations","authors":"A. Kamath, H. Bihs, Csaba Pákozdi","doi":"10.1115/OMAE2018-77925","DOIUrl":"https://doi.org/10.1115/OMAE2018-77925","url":null,"abstract":"Typical offshore structures are designed as tension-leg platforms or gravity based structures with cylindrical substructures. The interaction of waves with the vertical cylinders in high sea states can result in a resonant response called ringing. Here, the frequency of the structural response is close to the natural frequency of the structure itself and leads to large amplitude motions. This is a case of extreme wave loading in high sea states. This understanding of higher-order wave forces in extreme sea states is an essential parameter for obtaining a safe, reliable and economical design of an offshore structure. The study of such higher-order effects needs detailed near-field modelling of the wave-structure interaction and the associated flow phenomena. In such cases, a Computational Fluid Dynamics (CFD) model that can accurately represent the free surface and further the wave-structure interaction problem can provide important insights into the wave hydrodynamics and the structural response. In this paper, the open source CFD model REEF3D is used to simulate wave interaction with a vertical cylinder and the wave forces on the cylinder are calculated. The harmonic components of the wave force are analysed. The model employs higher-order discretisation schemes such as a fifth-order WENO scheme for convection discretisation and a third-order Runge-Kutta scheme for time advancement on a staggered Cartesian grid. The level set method is used to obtain the free surface, providing a sharp interface between air and water. The relaxation method is used to generate and absorb the waves at the two ends of the numerical wave tank. This method provides good quality wave generation and also the wave reflected from the cylinder are absorbed at the wave generation zone. In this way, the generated waves are not affected by the wave interaction process in the numerical wave tank. This is very essential in the studies of higher-order wave interaction problems which are very sensitive to the incident wave characteristics. The numerical results are compared to experimental results for higher-order forces on a vertical cylinder to validate the numerical model.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129305909","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}
Pan Fang, Yuxin Xu, Shuai Yuan, Yong Bai, Peng Cheng
Fibreglass reinforced flexible pipe (FRFP) is regarded as a great alternative to many bonded flexible pipes in the field of oil or gas transportation in shallow water. This paper describes an analysis of the mechanical behavior of FRFP under torsion. The mechanical behavior of FRFP subjected to pure torsion was investigated by experimental, analytical and numerical methods. Firstly, this paper presents experimental studies of three 10-layer FRFP subjected to torsional load. Torque-torsion angle relations were recorded during this test. Then, a theoretical model based on three-dimensional (3D) anisotropic elasticity theory was proposed to study the mechanical behavior of FRFP. In addition, a finite element model (FEM) including reinforced layers and PE layers was used to simulate the torsional load condition in ABAQUS. Torque-torsion angle relations obtained from these three methods agree well with each other, which illustrates the accuracy and reliability of the analytical model and FEM. The impact of fibreglass winding angle, thickness of reinforced layers and radius-thickness ratio were also studied. Conclusions obtained from this research may be of great practicality to manufacturing engineers.
{"title":"Investigation on Mechanical Properties of Fibreglass Reinforced Flexible Pipes Under Torsion","authors":"Pan Fang, Yuxin Xu, Shuai Yuan, Yong Bai, Peng Cheng","doi":"10.1115/OMAE2018-77354","DOIUrl":"https://doi.org/10.1115/OMAE2018-77354","url":null,"abstract":"Fibreglass reinforced flexible pipe (FRFP) is regarded as a great alternative to many bonded flexible pipes in the field of oil or gas transportation in shallow water. This paper describes an analysis of the mechanical behavior of FRFP under torsion. The mechanical behavior of FRFP subjected to pure torsion was investigated by experimental, analytical and numerical methods. Firstly, this paper presents experimental studies of three 10-layer FRFP subjected to torsional load. Torque-torsion angle relations were recorded during this test. Then, a theoretical model based on three-dimensional (3D) anisotropic elasticity theory was proposed to study the mechanical behavior of FRFP. In addition, a finite element model (FEM) including reinforced layers and PE layers was used to simulate the torsional load condition in ABAQUS. Torque-torsion angle relations obtained from these three methods agree well with each other, which illustrates the accuracy and reliability of the analytical model and FEM. The impact of fibreglass winding angle, thickness of reinforced layers and radius-thickness ratio were also studied. Conclusions obtained from this research may be of great practicality to manufacturing engineers.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"429 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126088481","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}
Numerical investigation on storm surge characteristics would benefit the planners and designers of coastal structures and offshore platforms along the Krishna-Godavari (K-G) basin. The adjoining coastline has a wide range of geomorphological features and varying geometries due to the sediment deposition from the two major rivers, Krishna and Godavari. Two severe cyclonic storms (SCS) Laila (2010) and Helen (2013) that approached the basin from two different directions and made landfalls closer to each other were analyzed for determining the storm surge heights and currents along the K-G river basin. The maximum water elevations and maximum currents during the storm event and evolution of storm surge heights at different locations were studied. It could be concluded from the study that when a SCS event approaches K-G basin, in addition to the tide and wave effect, a maximum storm surge height and current of 1 m and 1.2 m/s can be expected along the coast, respectively. Similarly, the surge and current in the offshore regions were found to be 0.3 m and 0.8 m/s, respectively. These values may be considered while deriving design parameters for the offshore installations. The critical regions in the basin were identified where high surge heights and currents are expected.
{"title":"Surge Height and Current Estimation Along K-G Basin","authors":"Maneesha Sebastian, M. Behera","doi":"10.1115/OMAE2018-77945","DOIUrl":"https://doi.org/10.1115/OMAE2018-77945","url":null,"abstract":"Numerical investigation on storm surge characteristics would benefit the planners and designers of coastal structures and offshore platforms along the Krishna-Godavari (K-G) basin. The adjoining coastline has a wide range of geomorphological features and varying geometries due to the sediment deposition from the two major rivers, Krishna and Godavari. Two severe cyclonic storms (SCS) Laila (2010) and Helen (2013) that approached the basin from two different directions and made landfalls closer to each other were analyzed for determining the storm surge heights and currents along the K-G river basin. The maximum water elevations and maximum currents during the storm event and evolution of storm surge heights at different locations were studied. It could be concluded from the study that when a SCS event approaches K-G basin, in addition to the tide and wave effect, a maximum storm surge height and current of 1 m and 1.2 m/s can be expected along the coast, respectively. Similarly, the surge and current in the offshore regions were found to be 0.3 m and 0.8 m/s, respectively. These values may be considered while deriving design parameters for the offshore installations. The critical regions in the basin were identified where high surge heights and currents are expected.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124023653","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}
Xi Chen, Yushen Huang, Peng Wei, Zhiguo Zhang, F. Jin
Simulations of propeller E1619 of two models with different scales are presented using an in-house numerical code based on the solution of the Reynolds averaged Navier-Stokes equations for the purpose of analyzing the scale effect on propellers. Propeller open water performance at given advance coefficient was obtained and compared against experimental data, showing good agreement. In aspect of CFD results, scale effect is not obvious. ITTC’78 Performance Prediction Method is applied to correct both experimental and computational open water performance of model 1. Computational KT of model 2 and corrected KT of model 1 agrees well, but the difference between computational KQ of model 2 and corrected KQ of model 1 is not neglectable. The locations of the tip vortex core of the two models are similar to each other, and so is the pressure and fluid velocity distribution. The absolute value of pressure on the blades of the smaller model is higher than the bigger model. The fluid axial velocity around the smaller model is higher than the bigger model.
{"title":"Numerical Analysis of Scale Effect on Propeller E1619","authors":"Xi Chen, Yushen Huang, Peng Wei, Zhiguo Zhang, F. Jin","doi":"10.1115/OMAE2018-78213","DOIUrl":"https://doi.org/10.1115/OMAE2018-78213","url":null,"abstract":"Simulations of propeller E1619 of two models with different scales are presented using an in-house numerical code based on the solution of the Reynolds averaged Navier-Stokes equations for the purpose of analyzing the scale effect on propellers. Propeller open water performance at given advance coefficient was obtained and compared against experimental data, showing good agreement. In aspect of CFD results, scale effect is not obvious. ITTC’78 Performance Prediction Method is applied to correct both experimental and computational open water performance of model 1. Computational KT of model 2 and corrected KT of model 1 agrees well, but the difference between computational KQ of model 2 and corrected KQ of model 1 is not neglectable. The locations of the tip vortex core of the two models are similar to each other, and so is the pressure and fluid velocity distribution. The absolute value of pressure on the blades of the smaller model is higher than the bigger model. The fluid axial velocity around the smaller model is higher than the bigger model.","PeriodicalId":124589,"journal":{"name":"Volume 7B: Ocean Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126703714","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：