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Browsing by Title: 71 Scientific Journals of the Maritime University of Szczecin

  • Buse, Hauke; Spangemacher, Lars; Fröhlich, Siegmund; Schüning, Thomas (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The current article describes the basics and prospects of the ultrasound-assisted cleaning of shell and tube heat exchangers that are used, e.g., on ships. A main issue of seawater heat exchangers is their clogging. After a certain operating time, the fouling process (barnacles, algae, etc.) starts, which results in a decreased performance that produces a noticeably reduced flow rate and a declining transmission of heat energy. Based on the current state of the art, heat exchangers are cleaned by mechanical or chemical (CIP, cleaning in place) methods. Especially on ship-based systems, a mechanical cleaning in very narrow spaces can be difficult and the usage of chemicals for CIP may generally be prohibited. An ultrasound-assisted cleaning would significantly save time and manning. Based on previous experiments, a test reactor represented by a shell and tube heat exchanger with ultrasound-assisted cleaning has been designed. A FEM (finite element method) simulation is performed to provide information about the ultrasound power distribution inside the reactor. Further, the assembly and commissioning of the test reactor with associated comparative measurements were carried out, which are also reported here.
  • Gucma, Michalina; Deja, Agnieszka (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This paper discusses the use of satellite tracking during an environmental disaster at sea, and it assesses the possibility of using remote sensing imagery captured by satellites using multispectral cameras and synthetic-aperture radar (SAR). This study is based on scientific literature and satellite tracking of the X-Press Pearl container ship disaster, which involved the EO-Browser platform. The purpose of this paper is to assess selected remote sensing methods for detecting and tracking marine pollution. The first part of the paper discusses satellite tracking of the X-Press Pearl disaster. The second part focuses on evaluation of the quality of remote sensing imagery from satellites and aircraft, when taking weather conditions into consideration. It should be noted that the research was conducted in real time when the incident occurred. News about the accident was also tracked in real time, allowing for a thorough analysis of the incident and, thus, an assessment of the different sensing systems. Although research on such disasters is crucial for the protection of the marine environment, scientific literature on this topic remains limited. This research area is very important for the protection of the marine environment, in the context of looking for solutions to these issues.
  • Czapliński, Wojciech; Gąsowski, Wojciech (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The Automatic Identification System (AIS) device is mandatory for ships that comply with the International Convention for the Safety of Life at Sea (SOLAS). AIS is intended for vessel traffic monitoring to improve shipping safety. In the examined area, the base station received 22 128 345 messages in April 2019. Approximately 80% of these messages included position reports, which were subjected to geospatial analysis. One possible utilization of AIS messages is used in an intelligent maritime transport statistics production system called TranStat in the Gospostrateg project. This specific study compares the speed of executing geospatial queries in a relational PostgreSQL database engine and a non-relational MongoDB database engine. For the purpose of this research, we have defined four AIS datasets, four test polygons of varied number of vertices, and a reference point on a fairway. The tests were used to assess the execution of the queries in a database that returns the number of ships located in a predefined area and the number of ships located at a preset distance from the defined point. It has been determined from the test results that test queries are performed faster and data stored in the database occupy less disk space in MongoDB than in PostgreSQL. Faster geospatial analysis of AIS messages may improve the navigation safety by earlier detection of dangerous situations.
  • Wiaterek, Daniel; Chybowski, Leszek (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The purpose of this paper is to present the results of a query aimed at assessing the validity of the topic of crankcase explosions prevention in the main marine engines. The study takes into account the engine type, engine manufacturer, ship’s age, accident severity, ship’s location at the time of the incident, and the share of fatal accidents in the analyzed population of crankcase explosions. One of the primary hazards associated with offshore and deep-sea ship operations – and primarily ship power plants – are fires and explosions that result in accidents and incidents with an average frequency of 60 days. This paper discusses the actuality of crankcase explosion hazards in the main propulsion engines of various types of sea vessels. The assessment was made based on the results of a statistical analysis of historical data from 1972 to 2018. The methodology consisted of three stages: (1) a selection query to obtain the source data, (2) analysis of the obtained results (data separation, extraction of additional information, and statistical analysis), (3) synthesis of the obtained information, and drawing conclusions about the numerical indicators describing the statistical distribution of individual events for the given evaluation criteria. The analysis showed that the risk of crankcase explosions affects ships of all ages – both in crosshead (31%) and trunk piston engines (61%) – and that the number of serious incidents (67%) remained constant over the investigated period. Half of all incidents occurred on vessels younger than 15 years old. 58% of explosions took place in engines of the most popular prime movers manufacturers. The probability that a main engine crankcase explosion will result in injury or death is 17.34%.
  • Ganjgani, Arman Aghaei; Ghassemi, Hassan; Ghiasi, Mahmoud (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This paper investigates the effect of buoys and a clump weight on the mooring lines and the dynamic response of the floating platform. The full-scale of the OC4-DeepCwind semisubmersible FOWT platform is analyzed using the boundary element method (BEM) with ANSYS-AQWA software, when considering regular wave conditions. Platform motions and mooring line tension in the surge, heave, and pitch are presented and discussed in the time domain analyses (TDA) and frequency domain analyses (FDA). Validation is performed by compression of the platform motion RAO and the fairlead tension RAO magnitudes in the surge, heave, and pitch (for both numerical and experimental data) under seven sea states’ regular waves. The results show that increasing the number of buoys at a constant volume decreases the surge and pitch motion amplitude, while the heave motion increases slightly. Adding the buoy and clump weight (type 1) to the mooring line reduces the oscillation amplitude tension. In addition, raising the number of buoys increases the oscillation tension.

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