一种撬冰式破冰艏设计及静水阻力计算

基于近年来对X型艏与撬冰式船首的研究，设计一种能够兼顾无冰水域阻力特性的新型撬冰式破冰艏。通过数值模拟计算两型主尺度相同但分别具有新型破冰艏与传统球鼻艏的海工辅助船的静水阻力，并进行对比以及通过船模试验进行验证。结果表明，具有新型破冰艏的船舶在设计航速下的阻力更小，为破冰船静水阻力性能与破冰性能无法同时兼顾的问题提供了新的解决思路。     

极地船连续破冰阻力数值模拟研究

连续破冰是自破冰型极地船舶中最常用的破冰模式,连续破冰阻力精确计算是极地船舶航行性能预报和船型优化设计的基础。论文提出一种基于预设冰网格技术的连续破冰阻力数值模拟方法,预先对船体水线附近的线型进行分层离散及对冰场进行方形网格离散,通过几何计算和受力分析数值模拟连续破冰进程及产生的破冰阻力分量。进一步考虑连续破冰阻力与运动耦合效应,在时域内建立船体6自由度运动微分方程,数值求解获得连续破冰阻力时间历程结果。利用该数值模拟方法计算获得了一艘PC3级极地油船连续破冰阻力时间历程结果,并将冰阻力有义值与对应的模型试验结果进行了对比。研究表明,数值模拟获得的连续破冰阻力时历结果能够反映连续破冰进程,数值模拟获得的冰阻力有义值与模型试验结果的误差在12%以内。论文的数值模拟方法能够高效、精确地模拟连续破冰进程及冰阻力,具有一定的工程应用价值。     

破冰结构与冰载荷相互作用下的破坏模式和损伤机理研究

本文首先利用LS-DYNA建立各向同性粘塑性有限元数值模型,并结合ISO推荐压强-面积理论曲线和相关学者的实验数据,验证数值模型的可靠性。其次,比较两种典型破冰结构的破冰机理和破冰效果,对破冰船在行进方向受到的阻力分别与首部外板倾角和水线面首部夹角的关系做了讨论。最后,分析了普通船舶船首与冰层碰撞时的损伤特点。结果表明：冰刀式破冰结构的破冰作业效率比压溃式更高,而压溃式破冰结构的安全性要比冰刀式更好;船舶与冰排相撞时,船首的易受损部位主要分布在首柱后侧临近区域和两侧船-冰接触区域,其中外板吸能最多,横向骨材吸收撞击时所产生的能量多于纵向骨材。因此,要结合实际航行水域的冰情、船舶功能和主机功率等因素,才能选取合适的破冰结构以达到最好的破冰效果;在破冰船船首设计和建造时,应增加船-冰碰撞区域船首外板的厚度,船首结构尽量采用横骨架式结构。     

破冰船的破冰能力估算方法初探

目前在实际设计工作中 ,破冰能力的估算有多种方法。结合一条 2 940kW多用途工作船的设计工作 ,对破冰船破冰能力估算方法进行了试算比较。     

基于流固耦合方法的船舶破冰阻力参数敏感性研究

本文基于带有塑性应变失效准则的弹性断裂失效模型建立平整冰有限元模型,采用LS-Dyna流固耦合方法对船舶在平整冰条件下航行的冰载荷开展了数值模拟,选取航速和平整冰厚度作为敏感性参数,分析了参数变化对破冰阻力的影响。研究发现:各方向上的冰载荷在时域上均存在一定的周期性,冰层在船艏撞击和浮力作用下,通常以多种破坏模式的混合方式同时出现;船舶在平整冰环境下的破冰阻力随航速和冰厚的提高基本呈线性增加的趋势,不同航速及冰厚条件下的破冰阻力数值计算结果与Lindqvist经验值的误差分别在-7.5%～13.1%和-10.8%～19.4%范围内,采用LS-Dyna流固耦合方法对船舶破冰阻力进行预报具有较高精度。     

带破冰功能全回转拖船的设计

为满足拖船在北方港口冬季冰期的持续作业要求,根据冰期的特殊作业环境,设计研发了带破冰功能的全回转拖船。在分析破冰船特点的基础上,将带破冰功能的全回转拖船设计成勺型艏、斜艏柱、大圆角船艉,使拖船同时具备破冰功能,满足冰期港口内的破冰及拖船拖带顶推作业的要求,为维护港口持续稳定的发展保驾护航。     

首艘破冰型三用工作船开工

<正>2015年9月24日,由上海船舶研究设计院(SDARI)为中海油服进行基本设计、详细设计以及生产设计的Tuna A100ice破冰型三用工作船在广新海工开工,共4艘,此次开工的是Tuna A系列中首艘破冰型三用工作船。Tuna A100ice是为海洋石油作业及开发生产提供服务,带有破冰功能的三用工作船,该船总长72 m,型宽14.4 m,破冰最大吃水5.25 m,可在厚度为0.6 m的层冰冰区内以8 kn速     

海洋石油支持船的破冰作业

文章对海洋石油支持船破冰作业进行了介绍,并阐述了作业前的准备工作、破冰方法以及在作业过程中和靠泊操纵期间应注意的事项。     

抗冰能力可与“雪龙”号匹敌破冰救助船“北海救118”开始“履职”

正2016年1月15日"北海救118"8 000 kW破冰型救助船交船。这是继"北海救117"之后,上海船舶研究设计院(SDARI)为交通运输部救捞局设计的第二艘破冰型救助船。"北海救118"是在此前8 000 kW海洋救助船的基础上,进行一系列抗冰功能的升级版。首部改为破冰型,确保首柱破冰、排冰;首部甲板采用蒸气伴热;尾部加装冰刀;上层建筑绝缘整体加厚,增强     

基于非线性有限元法的船舶冰区破冰数值模拟

应用非线性有限元法进行了破冰船冰区破冰数值模拟。通过比较数值模拟结果和试验结果,对冰体材料模型进行了验证;采用该冰体材料模型,对破冰船以不同航速在不同厚度的层冰中破冰航行时的动态响应进行了数值研究,给出了破冰过程中层冰的变形、冰力的大小以及冰的变形能和动能变化,分析了船速、冰层厚度对破冰阻力的影响。该研究结果对分析破冰船在层冰中破冰时的动态响应特性具有一定的参考价值。     

基于半经验公式方法的破冰船破冰阻力计算研究

传统Lindqvist半经验公式存在将不同船型阻力的计算结果均一化的缺点,本文基于船首不同区域的海冰破坏模式,采用船体纵向切片法对传统Lindqvist半经验公式进行了改进。通过将传统及改进后的半经验公式计算结果与模型实验结果进行比较,验证了改进的Lindqvist半经验公式计算结果的有效性和正确性。进而通过半经验公式计算方法,研究了船速和船舶吃水对船体所受破冰阻力的影响。结果表明,改进的Lindqvist半经验公式计算结果明显高于传统Lindqvist半经验公式,与实验值更为接近；船舶破冰阻力随船速呈近似线性增长的趋势,随船舶吃水的增加呈现减小的趋势。     

破冰技术在松花江流域栈桥保护中的应用

针对哈大铁路客运专线第二松花江特大桥1083号、1084号水中墩施工过程中钢栈桥在凌汛期间的防护工作,详述了破冰桩施工、流冰路开设、流冰的破碎与疏导等钢栈桥的综合防凌保护措施.这些措施的成功应用,使钢栈桥顺利度过凌汛期,并为今后类似工程提供了宝贵的经验.     

Dilated-polyhedron-based DEM analysis of the ice resistance on ship hulls in escort operations in level ice

The ice resistance on ships in escort operations in level ice are investigated using the discrete element method (DEM). A dilated polyhedron—generated by the Minkowski sum of a sphere and a polyhedron—is employed in the DEM; this dilated polyhedron-based DEM (DPDEM) is adopted to simulate the ship–ice interaction, wherein the contact force and bond-failure criterion are considered for the collision and fracture of sea ice, respectively. A three-point bending test was simulated with DPDEM, and a field test was conducted in the Bohai Sea to validate the DEM results. Further, a parametric analysis of flexural strength was conducted to identify the parameters involved in the bond-failure criterion. The ice resistance on icebreakers and cargo ships in level ice are simulated using DPDEM. The simulated ice resistances are compared with the Lindqvist and Riska formulas and the model test, which proves the validity of the DEM simulation. The interaction between ships and level ice is simulated parametrically to investigate the ice resistance on cargo ships with and without the icebreaker escort. Influencing factors such as ship speed, ice thickness, and ship breadth were examined to investigate the ice resistance on the escorted cargo ship. Analysis and change rules of the ice resistance on cargos affected by those factors were given.     

艏艉破冰模式极地船冰区划分及冰载荷弯矩剪力对总纵强度的影响

对于首尾破冰模式的极地船舶，规范中并没有详细给出其冰带划分的方法，仅仅提到尾部破冰参考艏部破冰区域划分，但由于船体尾部线型和艏部线型差距较大，故并不能很好的适用，本论文以一艘PC4级110kt极地原油船为例，就此针对尾破冰模式进行冰区带划分。 另外冰载荷产生的弯矩剪力对船体总体强度的影响也在本文中论述。     

Ship resistance when operating in floating ice floes: A combined CFD&DEM approach

Whilst climate change is transforming the Arctic into a navigable ocean where small ice floes are floating on the sea surface, the effect of such ice conditions on ship performance has yet to be understood. The present work combines a set of numerical methods to simulate the ship-wave-ice interaction in such ice conditions. Particularly, Computational Fluid Dynamics is applied to provide fluid solutions for the floes and it is incorporated with the Discrete Element Method to govern ice motions and account for ship-ice/ice-ice collisions, by which, the proposed approach innovatively includes ship-generated waves in the interaction. In addition, this work provides two algorithms that can implement computational models with natural ice-floe fields, which takes floe size distribution and randomness into consideration thus achieving high-fidelity modelling of the problem. Following validation against experiments, the model is shown accurate in predicting the ice-floe resistance of a ship, and then a series of simulations are performed to investigate how the resistance is influenced by ship speed, ice concentration, ice thickness and floe diameter. This paper presents a useful approach that can provide power estimates for Arctic shipping and has the potential to facilitate other polar engineering purposes.     

Ship resistance when operating in floating ice floes: Derivation,validation, and application of an empirical equation

With the effects of global warming, the Arctic is presenting a new environment where numerous ice floes are floating on the open sea surface. Whilst this has improved Arctic shipping navigability in an unprecedented way, the interaction of such floes with ships is yet to be understood to aid the designing of ships and route planning for this region. To further explore this topic, the present work develops a procedure to derive an empirical equation that can predict the effects of such floes on ship resistance. Based on a validated computational approach, extensive data are extracted from simulations of three different ships with varying operational and environmental conditions. The ice-floe resistance is shown to strongly correlate with ship beam, ship buttock angle, ship waterline angle, ship speed, ice concentration, ice thickness and floe diameter, and the regression powers of each of the parameters on resistance are ascertained. This leads to a generic empirical equation that can swiftly predict ice-floe resistance for a given ship in a given condition. Subsequently, demonstrations are given on the incorporation of the derived equation into a set of real-time Arctic ship performance model and voyage planning tool, which can predict a ship's fuel consumption in ice-infested seas and dynamically suggest a route with the least safety concern and fuel consumption. Moreover, the equation is validated by providing ice resistance prediction for experimental and full-scale conditions from multiple sources, showing high accuracy. In conclusion, the empirical equation is shown to give valid and rapid estimates for ice-floe resistance, providing valuable insights into ship designs for the region, as well as facilitating practical applications for polar navigation.     

Numerical Study of the Ice Breaking Resistance of the Icebreaker in the Yellow River Through Smoothed-Particle Hydrodynamics

A ship–ice–water interaction model is established using smoothed-particle hydrodynamics (SPH) to predict the ice breaking resistance of the icebreaker in the Ye...     

Full scale ice sea trials of Korean ice breaking research vessel ‘Araon’ on the big floes near Antarctica

A speed sea trial was performed in the Amundsen Sea in February and March of 2012. The Korean ice breaking research vessel “Araon” was used to check speed performance on the big floes. Two of ice trial cases were carried out. We describe the time history of location, the engine power, and the revolutions per minute during the ice trial, and the trajectory of the ship. Additionally, the measured ice properties are considered and discussed. The ice trial results were analyzed according to variation in ice thicknesses, ice strength, propulsion power, and the speed level of the ship. Our analysis results are compared to model test results and ice trial results. A correction to the target ice thickness was used to compare the power and speed relation in the same ice thickness because it is easy to know the relative speed performance of the ship. The Hamburgische Schiffbau-Versuchs Anstalt method was applied for the correction. The speed of Araon in big floes was higher than the speed in level ice. The speed after the correction at 10 MW of power and 103 cm of ice thickness was 5.4 knots based on analysis results.     

极地物探船冰载荷有限元计算方法

采用LS-DYNA有限元软件建立极地物探船的船-水域-海冰有限元模型，计算得到该型船在设计破冰厚度和设计航速下的冰载荷量和冰载荷时程曲线，并进一步研究冰体单元尺寸对冰载荷计算结果的影响。研究表明，冰载荷最大值随冰体有限元单元尺寸减小而减小。对比相关冰载荷经验公式计算结果，最终确定合理的冰体单元尺寸。研究结果对极地物探船的结构设计和结构安全性评估具有重要意义。