Publications
Sushmit Dhar, Eirik Mikal Samuelsen, Masoud Naseri, Karl Gunnar Aarsæther, Kåre Edvardsen, 2022. "Spray Icing on ONEGA Vessel – a Comparison of Liquid Water Content Expressions", Proceeding of the 41st International Conference on Ocean, Offshore, and Arctic Engineering (OMAE), June 5-10, Hamburg.
Available at The American Society of Mechanical Engineers and Munin UiT
Abstract
The risk of sea-spray icing on vessels and marine structures in cold regions highlights the need for an accurate and robust marine-icing estimation model. To develop such a model, it is crucial to accurately determine the quantity of liquid water available for freezing on the structure, as it directly influences ice formation. As sea spray constitutes the primary source of liquid water contributing to marine icing, researchers have often focused on measuring sea-spray flux from field campaigns to establish empirical expressions for icing estimation. However, due to the lack of standardised equipment or methods for such measurements and concerns regarding the generalisability and transferability of resulting empirical expressions, researchers have resorted to employing a variety of equipment and techniques tailored to their specific research requirements. Nevertheless, these approaches have inherent limitations. This paper introduces a novel spray collector device inspired by the cyclone separator, capable of performing real-time autonomous spray flux measurements on vessels and moving platforms. The collector is constructed using carbon fibre-infused nylon material, ensuring durability in harsh cold marine climates. Computational Fluid Dynamics (CFD) simulations and laboratory tests demonstrate that the design of the new collector is more efficient than that of the previously employed devices, particularly at higher wind speeds. The device is currently deployed on a fish farm in Northern Norway in order to assess its performance in field conditions. The paper also shares preliminary findings, experiences, and limitations encountered during the deployment period.
Sushmit Dhar, Masoud Naseri, Hassan Abbas Khawaja, Kåre Edvardsen, Tiantian Zhu, 2024. Design, development and deployment of a novel sea spray collector for sea-spray flux measurements, Cold Regions Science and Technology, February(2024), pp. 104096.
Available at Journal of Cold Regions Science and Technology and Munin UiT
Abstract
The risk of sea-spray icing on vessels and marine structures in cold regions highlights the need for an accurate and robust marine-icing estimation model. To develop such a model, it is crucial to accurately determine the quantity of liquid water available for freezing on the structure, as it directly influences ice formation. As sea spray constitutes the primary source of liquid water contributing to marine icing, researchers have often focused on measuring sea-spray flux from field campaigns to establish empirical expressions for icing estimation. However, due to the lack of standardised equipment or methods for such measurements and concerns regarding the generalisability and transferability of resulting empirical expressions, researchers have resorted to employing a variety of equipment and techniques tailored to their specific research requirements. Nevertheless, these approaches have inherent limitations. This paper introduces a novel spray collector device inspired by the cyclone separator, capable of performing real-time autonomous spray flux measurements on vessels and moving platforms. The collector is constructed using carbon fibre-infused nylon material, ensuring durability in harsh cold marine climates. Computational Fluid Dynamics (CFD) simulations and laboratory tests demonstrate that the design of the new collector is more efficient than that of the previously employed devices, particularly at higher wind speeds. The device is currently deployed on a fish farm in Northern Norway in order to assess its performance in field conditions. The paper also shares preliminary findings, experiences, and limitations encountered during the deployment period.
Sushmit Dhar, Hassan Abbas Khawaja, 2023. Real-Time Ship Draft Measurement and Optimal Estimation Using Kalman Filter. The International Journal of Multiphysics, 17(4), pp. 407-425.
Available at The International Journal of Multiphysics and Munin UiT
Abstract
Ship operators typically depend on the visual method for draft reading, which may lead to errors or approximations, and it further introduces draft survey calculation errors and can not provide continuous updates. Ensuring accurate real-time ship draft measurement becomes crucial for enhancing navigational safety, optimizing vessel performance, and achieving precise cargo and consumable measurements. With the current approach towards automation and remote operation of ships, the need to rely on the accuracy of the measurements provided by the sensors has increased. Although different sensor types are gradually being adopted for draft measurement, they encounter challenges in the demanding marine environment which may result in noisy and inaccurate readings. This paper aims to estimate the true draft of a ship in different conditions from noisy sensor measurements using the Kalman filter algorithm. The purpose of the algorithm is to reduce uncertainty in draft measurement that is generated from inaccuracies in the sensor or from the dynamic marine environment. The paper involves designing the Kalman Filter algorithm for draft measurement to work within the different conditions the ship may experience. Simulating different situations and analyzing the result, the application of the filter shows the advantage in real-time draft measurement in both static and dynamic conditions.
Sushmit Dhar, Masoud Naseri, Hassan Abbas Khawaja, Eirik Mikal Samuelsen, Kåre Edvardsen, Javad Barabady, 2024. Sea-spray measurement tools and technique employed in marine icing field expeditions: A critical literature review and assessment using CFD simulations. Cold Regions Science and Technology, 217(January). pp. 104029.
Available at the Journal of Cold Regions Science and Technology and Munin UiT.
Abstract
Sea-spray icing resulting from sea spray droplets accreting on exposed surfaces poses a significant safety concern for vessels and marine structures operating in cold climate regions. One of the key parameters determining the amount of ice accretion is the quantity of incoming sea spray, which eventually comes in contact with the structure in the presence of brine film freezing temperature. Hence, to develop marine icing estimation models, researchers have been inclined towards conducting field measurements to acquire data on sea spray and its key characteristics, such as liquid water content (LWC, mass of spray water per unit volume of air), spray frequency and duration, and droplet size distribution. This paper provides a critical review of various techniques used by researchers for sea spray field measurements. By employing Computational Fluid Dynamics (CFD) simulation, this paper also evaluates the performance of instruments for measuring sea-spray flux employed in such field campaigns. Design issues and potential areas for improvement are identified and discussed, based on which further recommendations for improvement of sea spray data collection are provided. The study provides valuable insights for researchers planning field measurement expeditions and exploring viable options to design an efficient system for collecting sea spray data.
Tiantian Zhu, Masoud Naseri, Yiliu Liu, 2023. A Concept of Information-Based Strategy for Accident Prevention, Proceedings of the The 33rd European Safety and Reliability Conference (ESREL 2023) 3 – 8 September 2023, Southampton, UK.
Available at ESREL-Research Publishing Services and Munin UiT. ,
Abstract
With the increasing use of sensor technology, it has become common practice to use collected data to reduce uncertainty and ensure safety. This paper presents the concept of an information-based strategy for accident prevention that puts more weight on hazard detection and monitoring and makes use of data obtained. The information-based strategy can be considered as a new barrier for safety management. The functionality of this strategy is neither to reduce the probability of an undesired event nor to reduce its consequence directly but to create a state of knowing for decision-making. The proposed concept can provide theoretical support for remote safety management of e.g., offshore installations. In addition, it can promote investigation about safety information environment in the organization and information behavior in resolving risk-related problems. In this article, some existing accident causation theories to provide the rationale for the proposed concept are elaborated. In addition, it gives an overview of typical types of information needs and measures to facilitate the information-based strategy. At the end, some challenges and problems which need to be solved to promote the application of the proposed concept are discussed.