Public Defence in Marine and Arctic Technology, M.Sc. Zongyu Jiang

This thesis explores the complex interactions between ships and ice in Arctic conditions, a subject of growing importance due to increased maritime activity in the region driven by climate change. The reduction of sea ice has opened new routes in the Arctic region, presenting opportunities for shorter travel distances but significant risks due to harsh ice conditions and limited emergency response infrastructure. 

The study specifically focuses on evaluating the hydrodynamic influences on ice loads during ship-ice glancing impacts in the Marginal Ice Zone (MIZ). Traditional ice load assessment methods often overlook wave-induced motions and hydrodynamic interactions, leading to potential inaccuracies. To address these gaps, this thesis develops methodologies that incorporate effects of waves and ship-ice hydrodynamic interactions. 

This thesis introduces a potential flow approach to assess added mass and damping effects between ships and ice floes. This approach is supplemented by Computational Fluid Dynamics (CFD) models to analyze the physical significance of hydrodynamic coefficients. These highlight the importance of specific matrix sections of hydrodynamic coefficients in energy-based ice load evaluation. 

The main result of this research demonstrates that ice loads are significantly affected by both hydrodynamic interaction and wave-induced motions, which traditional models may underestimate. Notably, wave-induced motions showed a more pronounced influence. These findings suggest that accurate prediction models must consider these dynamic interactions to ensure the safety of vessels navigating in MIZ. 

This research provides a basis for more reliable design and operational strategies for ice-strengthened ships. The proposed methodologies can be applied in future research and practical applications related to ship navigation safety in icy regions.

Doctoral Student: Zongyu Jiang

Opponent: Prof. Yanlin Shao, Technical University of Denmark

Opponent: Prof. Wenjun Lu, Norwegian University of Science and Technology, Norway

Custos: Prof. Mikko Suominen, Aalto University School of Engineering, Department of Energy and Mechanical Engineering 

The public defense will be organized in Lecture Hall 216, Otakaari 4 and online on Zoom.

The thesis is publicly displayed 10 days prior to the defense in the publication archive Aaltodoc of Aalto University. 

Contact information of doctoral student: 

Doctoral theses in the School of Engineering: https://aaltodoc.aalto.fi/handle/123456789/49