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Browsing by Author Abramowski, Tomasz:

  • Abramowski, Tomasz (Scientific Journals of the Maritime University of Szczecin, Zeszyty Naukowe Akademii Morskiej w Szczecinie, 2010)
    The paper presents some selected results of research on applications of artificial intelligence to the optimization of main ship design parameters and hull shape coefficients with the ship transport efficiency as an objective function. Basics of ship transport formulation are concisely discussed, together with examples for different approaches to optimization. An example of neural network use for the determination of ship transport efficiency is given with an assessment of its ability for data generalization. Moreover, two optimization procedures are presented: one using genetic algorithms and the other with simulated annealing approach. Both procedures lead to the improvement of ship transport efficiency
  • Abramowski, Tomasz; Handke, Jakub (Scientific Journals of the Maritime University of Szczecin, Zeszyty Naukowe Akademii Morskiej w Szczecinie, 2010)
    The paper presents results of unsteady numerical analysis of propeller-rudder system. For the calculations the Ansys Fluent solver was employed. The governing equations are RANSE. The results of computed forces, pathlines and pressure distribution on propeller and rudder are given as a function of rudder deflection angle. Initial investigations point to a number of very interesting effects, e.g. the formation on the rudder for small angle of deflection, the resulting force coincident with the direction of ship speed moving ahead. For that reason the resulting force may be considered as an additional component of the thrust force. Presented analysis may be employed during design of ships which are expected to attain good manoeuvring performance (e.g. LNG carriers) or ships which are designed with diesel-electric propulsion installation where there is a possibility to recover energy from inertia when slowing down
  • Wilpiszewski, Wojciech; Abramowski, Tomasz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The analysis of the river-sea ships built over the past 15 years has been made; se-lected design parameters of the navigation region have been taken into particular con-sideration. The presented functions demonstrate the general trend of building this type of vessel and limited possibilities in changing the main dimensions, such as: length, beam, height and draught. The aim of this paper is to determine the possibilities of design changes for river-sea ships as there is a growing interest in this kind of transport.
  • Abramowski, Tomasz; , (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This study presents a wide range of possibilities resulting from the application of wing-in-ground boats as means of transport. Selected design and operation problems of this type of vessel are briefly discussed. The numerical example of calculations of viscous flow around the wing of a WIG craft gives a good view on the ground effect related with WIG craft motion.
  • Abramowski, Tomasz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The article presents an attempt at numerical wake determination of a ship moving with drift. For the calculation of viscous flow a numerical method based on the solving of RANS equations has been applied. A bulk carrier hull has been chosen for the analy-sis. The results show complex features of the flow in the stern area. Distributions of wake factor are strongly non-uniform both in radial and circumferential directions and the non-uniformity gets stronger as drift angle increases.
  • Abramowski, Tomasz; Sugalski, Karol (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This paper presents the general method for hull shape optimization of fishing boats with the objective of reducing resistance. In particular, it presents an example of the results of the application of resistance-reducing devices such as the ducktail, the cylindrical bulb and the streamlined bulbous bow. The resistance was determined using computational fluid dynamics (CFD). For the purpose of flow simulation, the OpenFoam system, distributed under an open source license, was used. The turbulent, unsteady flow with free surface liquid around the analyzed hulls was computed and investigated for potential resistance reduction. Ultimately, the calculation results were generalized by the parameterization of dimensionless geometric variables for the shape of a bulbous bow and were given in a form suitable for practical application in the hull design process.

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