Scaling principles for model testing in old brash ice channel

• Published in: Cold Regions Science and Technology
• Main Authors: Matala, Riikka, Suominen, Mikko
• Other Authors: Aker Arctic Technology Inc, Department of Mechanical Engineering, Aalto-yliopisto, Aalto University
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2023
• Subjects: Brash ice channel; Channel similitude number; Finnish-Swedish Ice Class Rules; Model scale test; Model test principle; Scaling law; Arctic; Kujala
• Online Access: https://aaltodoc.aalto.fi/handle/123456789/120557; https://doi.org/10.1016/j.coldregions.2023.103857

Funding Information: The research on model scale testing on brash ice channels was initiated by Aker Arctic Technology inc. This paper is strongly based on experiments, which were funded by Aker Arctic and Winter Navigation Research Board. The research and paper writing have been supported by K. Albin Johansson's Foundation. The authors thank professor Pentti Kujala for his advice and supervision of the research. Publisher Copyright: © 2023 The Author(s) Climate warming sets higher requirements for sustainability in ship industry, which fuels the introduction of stricter power restrictions and new types of ship hull design. The new designs invite us to reconsider the principles in model scale testing in ice, which is the state-of-the-art method to predict vessel's ice performance prior to its construction. Ice model testing principles were originally developed for the evaluation of performance in level ice at slow speed, but currently those principles are widely applied for ice model testing in other ice conditions as well. The forces forming the vessel resistance in a brash ice channel are different compared to forces forming the vessel resistance in level ice. In consequence, the current model scale testing principles are suboptimal when predicting vessel's performance in an old, frequently operated brash ice channel, as our earlier research indicates that the prediction is conservative especially for modern merchant ship bow shapes with high stem angles. An old brash ice channel is especially interesting, as it is the determining ice condition in Finnish-Swedish Ice Class Rules ice class granting process. This paper addresses the problem by introducing a new similitude number – a Channel number – to be applied alongside the currently applied Froude and Cauchy similitudes. The Channel number aims to realistically scale the dominating forces that form the resistance of the vessel in an old brash ice channel by developing further the modelling of the resistance component induced by displacing the ice ...