A discrete element model for brash ice simulations

Most merchant ships operating in the cold regions are notable to break ice themselves, they can only navigate in the bro-ken ice, the so-called brash ice channels. Today’s standard re-quires a model test in real brash ice conditions to be carried outand realistic additional resistances to be estimat...

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Bibliographic Details
Main Authors: Behnen, Jonas, Hisette, Quentin, Ehlers, Sören, von Bock und Polach, Rüdiger Ulrich Franz
Format: Conference Object
Language:English
Published: 2020
Subjects:
Online Access:http://hdl.handle.net/11420/8436
Description
Summary:Most merchant ships operating in the cold regions are notable to break ice themselves, they can only navigate in the bro-ken ice, the so-called brash ice channels. Today’s standard re-quires a model test in real brash ice conditions to be carried outand realistic additional resistances to be estimated from this. Theproblem is that they can only be performed at the end of the de-sign process. The possibility of changing the ship design withinthe development process can only be guaranteed by using a simu-lation tool, based on the Discrete Element Method. The problemwith the development of this numerical simulation is the correct-ness of the mapping of the physical behaviour of brash ice. Thephysical models used are often simplified and not sufficient torepresent the complex mechanical behaviour of brash ice. Thus,another problem with the use of numerical simulation is the se-lection of the correct parameters to describe the mechanical be-haviour. A concrete definition of the used material parametersdoes not exist and the experimental tests for the determination ofthe physical properties are often complex and not standardized.This paper examines the mechanical behaviour of brash ice andthe descriptive parameters of each ice rubble. On this basis, thephysical behaviour in nature is compared with the model used innumerical simulation. As a result, physical inconsistencies aredetermined and new solution approaches are proposed, for ex-ample in the form of a new contact model, an extension of thefriction model or a change of the descriptive particle shape.