A New Friction Coefficient Correction for Ship Model Scale Testing in Brash Ice Channel

The friction coefficient correction for model-scale testing in brash ice channel may have a significant impact on the power requirement for an ice class that is determined through model-scale testing. However, it is not clear how applicable the friction coefficient correction presented in the Finnish-Swedish Ice Class Rules (FSICR) guidelines is for ships having a vertical open water -optimized bow form, or if the tests are conducted in a brash ice channel formed from solid ice cubes as suggested by recent research.
This paper presents model-scale experiments in a brash ice channel conducted in Aalto Ice and Wave Tank. The experiments included resistance tests both with simplified hull forms and a conventional ship model with different friction coefficients. The brash ice channels were made either from common soft model ice or solid freshwater ice cubes. The tests results suggest that the friction coefficient correction given in the FSICR guidelines is applicable for hull forms having a vertical bow form (large buttock angle) when those are tested in typical (relatively soft) model ice. By contrast, when brash ice tests are conducted with solid freshwater ice cubes, the correction given by the rules does not appear directly applicable and further research is needed. This paper focuses on the tests in brash ice channel made from solid ice cubes.