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  • Author: Gheorghe Samoilescu x
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Abstract

This paper presents the design of a watercraft that will be made under a cross-border project. It shows the detailed construction plans of the hull, the basic requirements that any marine vehicle must meet, the hydrostatic and stability calculations for the watercraft in order to determine how its weight and the shape of the hull can affect its performance and safety; the assessment of the efforts developed within the hull are calculated with SolidWorks.

Abstract

The paper presents the evolution of electric motors from the point of view of the materials used. Magnetic materials and composite materials, which are used in the construction of electrical machines, are analysed. Composite materials based on magnetic materials have a large coercive field, a wider hysteresis cycle, they cannot be easily demagnetized and they absorb better the vibration energy - therefore the noise is reduced. In the design of electric machines, the aim is to obtain a higher magnetic permeability across the frequency spectrum and to reduce the losses in iron and copper. We analysed the radial electric motors with cylindrical magnets, electric motors in discoidal form with axial field and motors with magnets with transverse flux. Hard magnetic materials were presented and the advantage of their use was highlighted - they retain a significant residual magnetization which translates into a significant saturation magnetization. The synthesis of Fe nanoparticles is performed and the composite materials obtained from iron powders with organic or inorganic binders are analysed with the purpose of reducing iron losses in electric motors.

Abstract

This paper presents variants of propulsion systems as the main factor in the analysis and design of the power system of a sea-going or river vessel; this topic is also under research study within two doctoral theses. The analysis of the ship - main propulsion- thruster assembly is made according to the requirements imposed by the market economy. The parameters to be considered when choosing a propulsion system are: the cost of the investment, the specific cost of transport that depends both on the specific fuel consumption and on the number and level of pay of the crew members operating the propulsion system, the propulsion efficiency, the high safety in handling, and the control accessibility during operation. The Pod and Azipod propulsion systems are analyzed in terms of advantages and disadvantages compared to conventional propulsion systems. The azimuth thrusters can ensure maximum push in any direction regardless the speed of the ship, and thus can change the course of the ship according to its handling needs. The azimuth thrusters do not only operate in horizontal but also in oblique angles, providing the ship with great maneuverability, even at low speeds, where classical rudder systems have poor performance

Abstract

This paper presents aspects of the steering gear onboard a merchant ship by analyzing aft and bow systems based on automation and use of modern propulsion. The choice of the transverse propeller is based on several economic considerations (its price, consumption, efficiency, etc.), technical considerations (positioning, size, vibrations induced in the ship’s hull), and maneuverability considerations (the ship’s turning rate under the action of the propeller. Accordingly, the propulsion system can come in various sizes, power values, shapes of the tunnel, and can present fixed or variable pitch propellers. Depending on the maneuverability of the ship, the transverse propulsion is analyzed by taking into account two tests: the turning of the transverse propulsion system test in calm and windy weather, and the steering test. The automation system is designed to control and monitor the on-board operational systems and equipment, and it encompasses a wide range of control, monitor and alarm. The integrated navigational equipment includes the following sub-systems: navigation consoles, ship handling consoles, dynamic positioning consoles, anchoring and deck operations consoles, and propulsion system control consoles. The propulsion control system is especially dedicated to the propeller and thruster control system, resulting in a joint control system, and the cables are reduced in number since the communication lines are used in series. The mandatory condition for successfully solving the problem with the complex automation of naval installations and equipment is the construction of complex automatic control systems (ACS), consisting of: automated commands or remote controls, a system of collecting, processing and displaying information, as well as a system of control, fault detection and diagnosis

Abstract

The paper analyses the role of control and monitoring of electro-energetic equipment in order to reduce operational costs, increase profits and reduce carbon emissions. The role of SCADA and EcoStruxure Power systems is presented and analysed taking into account the energy consumption and its savings. The paper presents practical and modern solutions to reduce energy consumption by up to 53%, mass by up to 47% and increase the life of the equipment by adjusting the electrical parameters. The Integrated Navigation System has allowed an automatic control and an efficient management. For ships, the implementation of an energy efficiency design index and new technologies was required for the GREEN SHIP project.

Abstract

The paper analyzes, starting from the Integrated Management System, the role of automation, the role of the officer and the role of the Energy Management System on board the ship. The implementation of an EnMS establishes the structure and discipline of identifying energy flows, implementing management actions and, finally, applying technical solutions, which significantly reduce energy costs, reduce non-productive time in production, and reduce emissions. of Greenhouse Gases in the environment. The steps to be highlighted in the realization of energy management are analyzed.

Abstract

Different methods of dispersion magnetic fields solutions for single phase transformers are presented in this paper. The transformers are with cylinder windings placed onto a single column. The transformer construction transformer is in the mantle. The analytic equation expression of finding dispersion magnetic fields have been delivered and the obtained solution has been verified by the experimental field measurements.

Abstract

In this paper, the authors present the modelling methods and numerical calculation of the dispersion magnetic field of electrical machines, as well as the results of their validation through practical measurements. An adequate analytic formula for magnetic induction calculation is proposed by the authors. The experimental results validate the proposed analytic model. Moreover, the proposed model is valid for both near and far field regions.

Abstract

The paper analyses the results of performed measurements regarding the density of electromagnetic power at various points on board a ship, the noise level determined by the operation of certain broadcasting stations and the intensity of the radiated electric field by a station of 250 MHz. We have presented thereby the sources triggering natural and artificial electromagnetic disturbances with their pertaining components.

Abstract

Screening is one of the main ways to achieve the Electromagnetic Compatibility (EMC) in the electric and electronic devices and equipments onboard a vessel. The present paper analyses the results of certain measurements made in order to determine the screen efficiency from the point of view of damping the induction magnetic field. Starting from the calculus for the screen efficiency, measurements of the intensity and level of the electric field, of the power density, of the damping and of the screening factor were made. These measurements were made both in the presence and in the absence of the screen.