Arctic Marine Technology and Ice Mechanics
Arctic marine operations are increasing with growth in sea transportation as well as off-shore wind energy and drilling operations. The Arctic is a harsh but sensitive environment that sets stringent requirements for safety and efficiency. Our group combines expertise in mechanical and safety engineering, naval architecture, applied and solid mechanics and risk management to ensure that future operations are able to meet these requirements.
Our multidisciplinary Arctic marine technology research creates knowledge on the interactions of sea ice with vessels for ship design and operational contexts. This knowledge is applied in practical applications while also supporting marine policy. The development of safety requirements has to rely on concepts, methods and frameworks for safe technological and socio-technological systems for design and operations, and for managing associated risks. This serves society by increasing our understanding of how maritime safety is created and maintained, and how maritime risks can be effectively managed.
One active research area is ship-ice interaction, which is of crucial importance for understanding both the resistance of ships in ice and the ice-induced loads on ships navigating sea ice environments. We conduct extensive experiments and measurements in full and model scale, including simultaneous ice thickness and ice load measurements onboard vessels and experimental programs in Aalto Ice Tank. We aim to improve our understanding of the critical elements for the safe design and operation of ships, including the effect of stochastic ice-induced loads on ship performance in dynamic and complex ice fields.
We also have a strong focus on numerical ice mechanics. As ice loads are caused by a complex ice-structure interaction process in which ice breaks into discrete ice blocks, novel research methods are needed. We use and develop tools for discrete element and combined finite-discrete element method (DEM and FEM-DEM) simulations. DEM and FEM-DEM allow us to model long ice loading processes, while accounting for ice failure and individual ice blocks.
Our simulation-based analysis has provided new insight on ice mechanics. We have, for example, showed that the so-called force chains have an important role on the ice loads and have been able to quantify their effect. We have also studied the effect of ice properties on ice loads. In addition, we have used DEM and FEM-DEM to study the statistics of ice loads and the behavior of ice rubble.
A central part of our research is Aalto Ice Tank, a unique 40 x 40-meter ice basin. Typical ice tank experiments include resistance, propulsion and manoeuvring tests on ships in ice, tests on ice loads on marine structures, and modelling of natural ice formations, such as ice ridges and ice rubble. Aalto Ice Tank also enables a wide range of other experiments on the physical phenomena related to sea ice, such as experiments on ice fracture, and offers a platform for rigorous validation of numerical models.
The group chairs the Centre of Excellence for Arctic Shipping and Operations funded by the Lloyds Register Foundation and is a member of SAMCoT, the Center for Research-based Innovation on Sustainable Arctic Marine and Coastal Technology led by the Norwegian University of Science and Technology and funded by the Norwegian Research Council and international industry. The group has also other close international partners in USA, China and Japan.
Personnel: Professor Jukka Tuhkuri, Professor Pentti Kujala, Professor Arttu Polojärvi