Prøveforelesning og disputas – Ane Solbakken Sæterdal / Trial lecture and defense – Ane Solbakken Sæterdal

“Marine winterization – Measures to abate sea-spray icing”.

Avhandlingen er tilgjengelig her / The doctoral thesis is available here.

Auditoriet er åpent for publikum. Prøveforelesningen og disputasen vil også bli strømmet. Tilsvarende lenker til strømningen er tilgjengelig på forespørsel hos Diana Thordarson. Opptak av disputasen vil være tilgjengelig i en måned.
The auditorium is open to the public. The trial lecture and the defense will be streamed. Corresponding links are available upon request at Diana Thordarson. A recording of the defense will be available for one month.

Prøveforelesningen starter kl. 10:15 / The trial lecture starts at 10:15. Tittel / title:

“Winter navigation systems and ice classes - an introduction and comparison”.

Disputasen starter kl. 12:15 / The defense starts at 12:15.

Sammendrag av avhandlingen / Summary of the thesis:

This thesis includes the topic of sea-spray icing on vessels and structures and dives further into methods of ice management. Sea-spray icing is a challenge in cold waters, particularly for small and mid-sized vessels. Excessive ice accretion is hazardous for vessel stability, operations and personnel safety. Sea-spray icing from wave-vessel-wind interaction is a complex phenomenon. No measuring technique currently exists to fully capture the distribution of the incoming water flux over a moving vessel. Measuring the incoming flux as the fluid simultaneously undergoes a solidification process, adds even more challenges. Some records of the resulting ice thickness occur, but the research field generally lacks data. Creating tools to predict ice accumulation is a developing field of study, where tools e.g. computational fluid dynamics and machine learning have potential. Experimental data is crucial for model verification, and this thesis contributes with a comprehensive parameter study under laboratory conditions that could support further development of prediction models. Data from the parameter study was extended to investigate the threshold between melting and freezing. When the thermal capacity of the incoming water flux exceeds the freezing capacity of the existing ice or substrate, melting occurs. This threshold became a key principle for investigating an alternative way to mitigate ice accretion, deicing with flushing seawater.

Implementing the Polar Code in the SOLAS Convention 2017 was a great international step towards increasing the safety of vessels sailing in polar waters. The code requires an operational risk assessment and the individual vessel is obliged to carry systems for e.i., ice removal, that meet the requirements. The function-based requirements in the Polar Code detail end goals, but do not generally instruct how the goals should be met. Multiple methods for deicing and anti-icing are needed. Resource scarcity like electricity and personnel limits current solutions, and a larger toolbox at our disposal can increase flexibility, environmental performance, efficiency and safety.

Experiments were carried out to determine if flushing seawater could be a tool against sea-spray ice accumulation. Using seawater is not common practice, and this thesis is, therefore, a first approach to evaluate the method. Full-scale tests of deicing with seawater were performed on vessels and structures in varying meteorological conditions typical of larger parts of the Barents Sea. Seawater is an abundant resource, and the preliminary test from this thesis shows that utilizing seawater should be explored as a deicing and/or anti-icing method. Further work should include expanding the tested operating range and surface area, with distribution systems designed specifically for the purpose.

Veiledere / Supervisors:

Hovedveileder / Main supervisor:

Professor Per-Arne Sundsbø, Department of Building, Energy and Material Technology, Faculty of Engineering Science and Technology, UiT The Arctic University of Norway,

Biveileder / Co-supervisor:

As. Professor Eirik Mikal Samuelsen, Department of Physics and Technology, Faculty of Science and Technology, UiT The Arctic University of Norway.

Bedømmelseskomité / Evaluation committee:

• Professor Søren Ehlers, Institute for Ship Structural Design and Analysis, Hamburg University of Technology, 1. opponent,
• Dr. Olga Shipilova, Principal spesialist ved Det Norske Veritas, 2. opponent,
• Dr. Eirik Gjerløw, Department of Building, Energy and Material Technology, UiT The Arctic University of Norway, internt medlem og komiteens administrator / leader of the committee.

Prøveforelesning og disputas ledes av prodekan for forskning, Svein-Erik Sveen /

The trial lecture and defense are led by Vice Dean of research, Svein-Erik Sveen.

De som ønsker å opponere ex auditorio kan sende e-post til Svein-Erik Sveen / Opponents ex auditorio should contact Svein-Erik Sveen.