船舶在平整冰区行进过程的离散元分析
2017-10-12狄少丞季顺迎薛彦卓
狄少丞,季顺迎,薛彦卓
(1. 哈尔滨工程大学 船舶工程学院,黑龙江 哈尔滨 150001;2. 大连理工大学 工业装备结构分析国家重点实验室,辽宁 大连 116024)
船舶在平整冰区行进过程的离散元分析
狄少丞1,季顺迎2,薛彦卓1
(1. 哈尔滨工程大学 船舶工程学院,黑龙江 哈尔滨 150001;2. 大连理工大学 工业装备结构分析国家重点实验室,辽宁 大连 116024)
船舶在冰区航行中,冰荷载是船舶结构设计和安全航行的重要影响因素。采用具有黏结破碎特征的离散单元法对船舶在平整冰区的航行过程进行了数值分析。在船舶破冰过程的离散元模拟中,平整冰由球形颗粒黏结而成,同时考虑了海水浮力和拖曳力对海冰单元的作用,颗粒间的黏结作用可在海冰与船体的相互作用过程中发生破碎;船体由三角形单元构造,分析了在海水浮力、推进器推力及海冰共同作用下船体的六自由度运动特性。通过船体与海冰相互作用的离散元分析,确定了船舶在破冰过程中海冰作用在船体上的冰荷载,探讨了船舶推进器推力和海冰厚度对冰荷载的影响,并与Lindqvist船体冰阻力经验公式进行了对比。
平整冰;船体;离散元方法;冰荷载;破冰过程;海冰厚度
Abstract: During the navigation of ship in ice covered regions, the ice load on ship hull is a significant factor for the structure design and safe maneuvering of ships. In this study, the discrete element method (DEM) is applied to simulate the interaction between level ice and ship hull. The level ice is constructed with bonded spherical elements under the buoyancy and drag force of current. The bonded elements can be broken in the process of the interaction between level ice and ship hull. The ship hull is constructed with triangular elements and treated as a six-degree of freedom system. With the DEM simulations of the interaction between level ice and ship hull, the global ice resistance on ship hull in the process of ice breaking can be determined. The influences of propulsive force and ice thickness on ice load are also discussed based on the simulation results. The comparison of ice load between DEM simulation results and the empirical formula proposed by Lindqvist is presented. This study can be an aid to the structure design of ship and the navigation security in ice-covered fields.
Keywords: level ice; ship hull; discrete element method; ice load; ice breaking process; ice thickness
近年来,受全球气候变暖的影响,北极海冰覆盖面积持续减少,北极航道的夏季通航也成为可能[1-2],北极东北航道和西北航道的开通对我国海上运输有着重要的战略意义[3-5]。为此,我国从2012年开始在北冰洋的考察中针对北极航道开通的可行性进行了系统的调查[4]。……
