【作者】 刘德良；

【导师】 周力；

【作者基本信息】 大连理工大学 ， 船舶与海洋工程（专业学位）， 2018， 硕士

【摘要】 随着北极冰区的逐渐融化,人们对北极的兴趣也越来越浓厚。无论是科考船舶对北极的调查研究、资源的开发利用,还是商用船舶进行货物的贸易运输,这一切都离不开冰区船舶这一载体。由于航道内是冰水混合物,所以船舶避免不了与航道内碎冰产生相互作用,碎冰会增加船舶航行的阻力,这不仅会增加油耗和成本,同时也会增加航行的危险系数,严重影响船舶的航行性能。这就需要对冰区船舶的航行性能展开研究,然而目前我国对于冰区船舶的研究无论是从理论还是从工程上都尚处于初步阶段。因此,本文的主要目的是探究各种因素对船舶碎冰阻力的影响。对冰区船舶碎冰阻力的研究方法一般包括经验公式、数值仿真、模型试验等几种方法。经验公式需要经过多年的实地实时观测,然后按统计学知识总结归纳;模型试验需要在专门的冰试验水池中进行,试验条件较为苛刻;数值仿真方法整体操作性更强,更容易实现。本文主要利用ANSYS、LS-DYNA通过数值仿真的方法研究冰区船舶碎冰阻力,船冰结构与流体之间的相互作用采用的是流固耦合算法。通过柱状结构与单块碎冰的碰撞模拟,探究多种因素对柱状结构物与单块冰碰撞力的影响。通过模拟探究发现:摩擦系数越大,结构物与冰块之间得碰撞合力越大;碰撞速度越大,法向碰撞力越大;随着冰块厚度的增加,法向碰撞力呈增大趋势;对于各向同性断裂材料,截断失效压力的值越大,法向碰撞力越大。通过船艏与碎冰的碰撞仿真计算,探究了各种因素对碎冰阻力的影响。最终得出的结论是:在其他因素相同的情况下,随着航行速度的增大,碎冰阻力均值呈线性增加的趋势,随着碎冰覆盖率的增大,碎冰阻力均值呈现逐渐增加的趋势,随着碎冰尺寸的增大,碎冰阻力均值也呈现出逐渐增加的趋势。更多还原

【Abstract】 With the melting of the Arctic ice,people’s interest in the Arctic is becoming more and stronger.Whether we conduct scientific investigation and exploit the Arctic resources by scientific research ship,all these activities are always inseparable from ships.Because of filling with ice-water mixture in the channel,the ship interact with crushed ice inevitable.The crushed ice will increase the resistance acting on ship,which not only increases the oil consumption and cost,but also increases the dangerous coefficient of navigation,which seriously affects the navigation performance of the ship.So it is necessary to study the navigation performance of ships in ice area.However,at present,the research on the ice area ships is still in the preliminary stage in both theory and engineering.Therefore,the main purpose of this paper is to explore the influence of various factors on the resistance of ship from collision beteween ship and ice.The research methods of crushed-ice resistance on ships generally include empirical formula,numerical simulation,and model test.The empirical formula needs actual measurements for many years,and then summed up according to the statistical knowledge.The model test needs to carriy out in the special ice test pool,and the test conditions are harsher.The numerical simulation method is operational and easier to be realized.Therefore,this paper mainly uses ANSYS/LS-DYNA to study the resistance by numerical simulation,and the interaction between the ship or ice structure and the fluid adopte ALE mothod.Through the collision simulation of columnar structure and single crushed ice,the influence of various factors on the collision force between columnar structure and single ice is explored.It is found that the greater the friction coefficient,the greater the resultant force is;the greater the collision speed,the greater the normal force is;the greater the thickness of the ice,the greater the normal force is.The more the value of failure pressure for the isotropic fracture material,the greater the normal force is.Several of factors on the resistance of crushed ice is explored through the collision simulation of ship’s bow and crushed ice.The conclusion is that when other factors are in the same condition,with the increase of the speed of navigation,the collision resistance from the crushed ice is increasing gradually.In addition,with the increase of the coverage rate of the crushed ice,the collision resistance from the crushed ice also shows an increasing trend.更多还原