Investigation On The Numerical Simulation For Motion Of Icebreaker During Icebreaking

With the exploitation of the polar resources and the development of the polar transportation, international and domestic academics have payed more and more attention to the studies on icebreakers. The characteristics of icebreakers sailing in ice and the interactions between the icebreaker and ice have become the research highlights. The thesis is based on the ideal assumptions of the icebreaking process, and the numerical simulations are done on the icebreaking motions. Investigations on the characteristics of icebreaking motions and icebreaking performance are done in the thesis.The main research contents are as follows:1、Based on the assumptions of ideal icebreaking motions process, the thesis presents the icebreaking pattern of the icebreaker and the characteristics of interactions between different parts of the icebreaker and ice. The equations of motions in six degrees of freedom are established.2、The numerical theory of the icebreaking motions is presented in detail, and the numerical model of the icebreaking motions is established. The repeated process composed of contact-crushing-bending failure is investigated.The position of the contact points and the crushing force between the icebreaker and ice are calculated. The bending failure of the ice is judged. The shape of the ice floes is calculated and the edge of the ice is updated.3、Based on the numerical theory of the interactions between the icebreaker and ice, the procedure is done using Fortran language. The numerical simulation of the icebreaking motions is done. The icebreaking motions involved transiting and turning operations are investigated. The trajectory of icebreaker and the shape of the ice edge and the time-varying curves of icebreaking forces are obtained. Based on the analysis of the image,the results of the numerical procedure are verified combined with the reality.4、 The effect of average crushing pressure on ice breaking motions and icebreaking force is investigated. The effect of the vertical motions and the transverse motions and the roll on icebreaking performance is investigated.