Session: 06-04-02 Marine Engineering and Technology II

Paper Number: 79919

79919 - Spray Icing on ONEGA Vessel- A Comparison of Liquid Water Content Expressions 

The hazards associated with ice accretion primarily due to impinging freezing sea spray on ship structures are considered serious safety concerns for ships operating in the colder regions. Ice accumulation on the higher parts is significantly threatening for smaller vessels such as fishing vessels which can destabilize and eventually capsize it. An accurate sea spray icing estimation model to evaluate the amount of ice accumulation during operations in these regions can make marine operations safer and can aid in designing effective winterization techniques. The accuracy of the present icing models for estimating icing on ships is substantially dependent on the input parameter of incoming spray flux generated by the wave-ship interaction. Most of the icing models use spray-flux estimations based on past empirical observations mainly obtained from fishing trawlers. The spray flux consists of liquid water content (LWC), duration and the distribution of the spray associated with structure impingement, and spray generation frequency.

This paper focuses on the LWC, which is one of the significant parameters of spray flux and aims to analyze the dependency of the output of the spray icing models on it. To illustrate this, we consider the case of the ONEGA fishing vessel, which capsized and sank after encountering heavy icing in the west of Yuzhny Island, Novaya Zemlya Archipelago, on 28 December 2020, claiming 17 lives. In this case, we assume the vessel to have minimum stability criteria prior to icing and identify the potential locations of accreted ice to estimate the likely amount of ice accumulation that destabilized the vessel, which ultimately capsized while raising the catch. Then this estimation is contrasted against the weight of ice accretion evaluated by the MarineIcing model for the Norwegian COast Guard (MINCOG). In order to demonstrate the dependency of MINCOG output on the LWC parameter, an analysis is carried out applying different LWC formulations available in the literature proposed by different researchers. In conclusion, more considerations such as accounting for the contribution of wind-generated spray flux and collecting multiple real-time spray-flux measurements to develop a more realistic spray-flux formulation may improve the accuracy of icing estimations by such models.

Presenting Author: Sushmit Dhar UiT - The Arctic University of Norway

Authors:

Sushmit Dhar UiT - The Arctic University of Norway
Eirik Mikal Samuelsen UiT - The Arctic University of Norway
Masoud Naseri UiT - The Arctic University of Norway
Karl Gunnar Aarsæther UiT - The Arctic University of Norway
Kåre Edvardsen UiT - The Arctic University of Norway