Day 2 Tue, September 21, 2010最新文献

{"title":"AURORA BOREALIS – A new European Combined Research Icebreaker and Drilling Vessel","authors":"W. Doelling, A. Delius, L. Lembke‐Jene","doi":"10.5957/icetech-2010-123","DOIUrl":"https://doi.org/10.5957/icetech-2010-123","url":null,"abstract":"The paper discusses the development of the AURORA BOREALIS, a new European Polar Research and Scientific Drilling Vessel with dynamical positioning capability in drifting ice. The Vessel will be designed as a heavy icebreaker with the highest polar ice class. She will be powered to break continuously multiyear ice of more than 2.5m thickness and she will be able to manage ice ridges up to 15m height and more. She shall perform research tasks including scientific drilling missions all-year-round in the Arctic and in Antarctica without any other assisting support vessels. One of the key issues in the required performance specification for the vessel is the mandatory performance of autonomous station keeping operations in drifting level ice of more than 2.0m thickness during drilling and other research tasks.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114900052","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}

{"title":"Effect of Moving Ice Loads on the Plastic Capacity of a Ship’s Structure","authors":"B. Quinton, C. Daley, R. Gagnon","doi":"10.5957/icetech-2010-110","DOIUrl":"https://doi.org/10.5957/icetech-2010-110","url":null,"abstract":"The IACS unified polar rules define the design ice load as a glancing impact on the bow shoulder. The load and structural response model in the polar rules ignore the tangential motions and assumes the interaction occurs at one location. If the impact duration were sufficient, the ice may “score” along the hull during a glancing impact. This paper examines the questions of how structure responds to moving loads, in comparison to normal loads. An explicit nonlinear numerical model was created and validated against full-scale physical experiments. Moving load scenarios were then simulated. The structure’s capacity to withstand moving loads causing “progressive damage” was found to be generally less than its capacity to withstand static loads.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132557873","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}

{"title":"Modeling of Pressured Ice Interaction with Ships","authors":"I. Kubat, M. Sayed, A. Collins","doi":"10.5957/icetech-2010-138","DOIUrl":"https://doi.org/10.5957/icetech-2010-138","url":null,"abstract":"The paper describes numerical simulations of ship transit through ice. The simulations employ a model which is based on solving the conservation of mass and linear momentum together with constitutive equations representing plastic yield. A cohesive Mohr-Coulomb criterion with a tension cut-off is used to represent the yield condition. The numerical solution approach is based on a Lagrangian-Eulerian hybrid formulation. A depth-averaged version of the model is used, whereby the stresses and velocities are averaged over ice thickness. Ice thickness build-up and lead opening are accounted for in the model. The ice cover is driven by prescribed displacements or pressures at the boundaries. Wind and water current drag are also included. The simulations address cases of ship moving at constant velocity through a uniform ice cover, of 200 m width and 1 km length. The geometry of the Canadian Coast Guard vessel, CCGS Louis S. St- Laurent, is used in the tests. The results give the evolution of the distributions of ice concentration, thickness and pressures. The ice force-time records are also produced. The predicted forces are compared to recently reported field measurements of ice forces on the CCGS Louis S. St-Laurent. The magnitude of the simulation forces are in agreement with the measurements. A parametric study examined the role of the following variables: velocity of the ship, ice concentration, ice thickness, and properties of the ice cover (angle of internal friction). The results indicate that velocity has the most pronounced effect on ice force. The concentration and thickness also had significant effects. The angle of internal friction has somewhat less significant effects. The simulations also examined ship transit under pressured ice, or convergence, conditions. Conditions at the lateral boundaries applied ice movements against the ship during transit. The simulations show the pressure build-up against the sides of the bow due to ice convergence, and the increase in the ice force on the ship. The results indicate that ice pressures on the ship are two orders of magnitude higher than the large-scale average stresses which are calculated over a 1 km length.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132889997","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}

{"title":"An Analysis of Sea Ice Conditions to Determine Ship Transits through the Northwest Passage","authors":"T. Mudge, D. Fissel, M. M. de Saavedra Álvarez, J. Marko","doi":"10.5957/icetech-2010-151","DOIUrl":"https://doi.org/10.5957/icetech-2010-151","url":null,"abstract":"An analysis was carried out to determine the duration of the summer shipping season for Deepwater vessels transiting through the Northwest Passage Route. The most likely route segment to obstruct shipping is in Viscount Melville Sound, which is typically characterized by the presence of high concentration mixtures of the deformed, thick first-year and multiyear ice. The period for ship transits through the Passage is determined from the computer-based analysis of digital Canadian Ice Service weekly ice charts which are available from the late 1960s to the present. Automated computer-based algorithms were developed to estimate the number of if any, weeks with ice conditions that would successfully allow transit. The results show a very large year-to-year variability in the duration of the summer shipping season with the trend towards slightly improving ice conditions. The possibility of future increases in old ice concentrations in western and central portions of Parry Channel due to an apparent trend towards more rapid passage of this old ice through the Queen Elizabeth Islands to the north may impede ship passages in the next decade by comparison with the last decade or two.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116662259","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}

{"title":"Global Ice Loads on Arctic Drillships","authors":"Bo Wang, C. Daley, M. Sayed, Jiancheng Liu","doi":"10.5957/icetech-2010-120","DOIUrl":"https://doi.org/10.5957/icetech-2010-120","url":null,"abstract":"This paper reports on an exercise to predict ice loads on Arctic drill ships using analytical, model ice basin test-based empirical, and numerical methods. An example drillship has been employed, and pack ice has been considered in theoretical and numerical analyses. Two analytical models for predicting the ice force have been employed for the head-on ice-ship interaction scenario with low ice concentration. One model is that the ice load is estimated as the average rate of momentum transfer between ice floes and ship hull. Another model is that the ice load is estimated based on the calculation of the motion and drag of ice floes as they move around the ship. In numerical modeling, a parametric study has been conducted to simulate different ice structure interaction scenarios using the Particle-In-Cell (PIC) method. Different parameters including ice thickness, ice concentration, ice movement velocity, and ice movement direction have been investigated in the interaction modeling. Based on numerical results, a formula for calculating the ice load has been developed to reflect the role of the pertinent parameters on expected ice forces and movements of the drillship. The comparison of results from all ice load models and numerical modeling shows a reasonable agreement. This study serves to help bound estimates of load and also provides insights into the different methods of global ice load prediction for this particular application.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126274665","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}

{"title":"MOERI’s Ice Model Test for Korean Icebreaking Research Vessel","authors":"C. Lee, Seong-Rak Cho, Seong-Yeob Jeong, Eun-Jee Chun","doi":"10.5957/icetech-2010-147","DOIUrl":"https://doi.org/10.5957/icetech-2010-147","url":null,"abstract":"In the near future, the number of ice-going breakers operating in the northern sea route will be increased, as potential international trade between the North Atlantic and the North Pacific region increases. Since many ice-going breakers are expected to be developed, various kinds of ice model tests will be carried out in order to improve their ice-going capability as well as their performance. This in turn leads to increased demand for physical model testing in ice to assist a design process and to improve a vessel’s ice-going capability and performance. The estimation of a ship’s resistance in ice-covered seas has been a very interesting topic to shipbuilders. Ice resistance is related to the propulsion of a ship, and it determines the engine power of the ship. Generally, ice resistance is related to ice conditions, such as ice thickness and ice flexural strength, and its operating condition (speed). In order to check the reliability and the accuracy of the ice test as a whole, some comparative studies were made. With the support of the Korean Government, the research community, and the ship-building industries, MOERI decided to build the next generation ice model basin at Daejeon. The MOERI ice model basin was completed at the end of September 2009 (see Figure 1). Since 2009, MOERI’s ice tank has produced more than 20 ice sheets, and a series of ice model tests for the Korean icebreaking research vessel was conducted. The test results are compared with those conducted in the Helsinki university ice model basin in 2004-2005.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128801024","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}

{"title":"Assessment of Ship Ice Loads in Pack Ice","authors":"C. Daley, Jiancheng Liu","doi":"10.5957/icetech-2010-141","DOIUrl":"https://doi.org/10.5957/icetech-2010-141","url":null,"abstract":"World trade and exploration for natural gas/oil in the Arctic/Subarctic has greatly stimulated the development of shipping in arctic regions. More and larger commercial vessels have or will operate in the harsh environments. This stretches the validity of the existing ship design rules and raises concerns. To deal with this challenge, owners, designers, operators and regulators have been trying to develop more and better design scenarios. This paper addresses such scenarios. Impacts between ships and the discrete ice floes are unavoidable. This paper develops an approach for ice load assessments for a ship interacting with discrete ice floes on the bow and midbody area. One typical scenario in those interactions in considered in this paper: a midbody impact with a second flow, following a glancing impact between the bow and a first ice floe. The assessed ice loads of the two impacts within this scenario are compared to the current requirements of the hull structural strength at the bow and mid-body. From the hull strength point of view, the safe navigation speeds were estimated due to various factors (mass, velocity, geometry). The paper highlights some of the challenges of direct design and hull strength checking.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124425572","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}

{"title":"Structural Integrity Assessment for a Polar Class Arctic Tanker under Ice Loads","authors":"John Dolny, She-wen Liu, Dongki Won, Jae-Yeol. Lee, Joong-Hyo Choi, M. Kwak","doi":"10.5957/icetech-2010-119","DOIUrl":"https://doi.org/10.5957/icetech-2010-119","url":null,"abstract":"The recent surge of interest in potential oil and gas reserves in the Arctic has resulted in vital technological developments in the field of Arctic shipping. New, larger vessels of novel designs are entering the region where the industry has limited experience. The design of these large vessels presents new challenges for designers and operators. ABS, DSME, and BMT Fleet have collaborated in a joint project focusing on the development of a 107,000 DWT Arctic crude oil tanker designed to comply with the IACS Polar Class PC4. Structural strength assessments of the bow and three midbody configurations subject to ice loads derived from the PC rules and several other ship-ice interaction scenarios were conducted. This paper presents the procedure and results of static nonlinear finite element analysis (FEA) and plastic grillage analysis used to simulate several identified high-risk ship-ice interaction scenarios.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129181405","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}

{"title":"The Transportation of Large Modules through the Northwest Passage","authors":"Gareth Igloliorte, A. Kendrick","doi":"10.5957/icetech-2010-177","DOIUrl":"https://doi.org/10.5957/icetech-2010-177","url":null,"abstract":"A review of the feasibility of transporting large modules through the Northwest Passage (NWP) via heavy lift vessels or a tug barge arrangement is discussed in this paper. The review included an assessment of ice conditions during the late spring, through early fall months, navigation hazards, regulatory requirements and heavy lift vessels on the market. The ice conditions in the Northwest passage were developed based on data from the Canadian Ice Service. The study developed estimated transit times through the NWP using a transit model based on the Transport Canada AIRSS standard.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126305432","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}

{"title":"North Slope Trends in Sea Level, Storm Frequency, Duration and Intensity","authors":"Nels J. Sultan, Kenton W. Braun, Dempsey S. Thieman, Ajay Sampath","doi":"10.5957/icetech-2010-155","DOIUrl":"https://doi.org/10.5957/icetech-2010-155","url":null,"abstract":"The tide gage at Prudhoe Bay provides the only continuous long term direct measurement of sea level on the Alaska North Slope. In addition to trends in mean sea level, it provides a record of storm surges and setdowns. Analysis of the sea level time series from 1993 to 2010 reveals no statistically significant trends in relative sea level, storm frequency, intensity and duration. The return period of sea level extremes are estimated.","PeriodicalId":408230,"journal":{"name":"Day 2 Tue, September 21, 2010","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122697665","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}