No 1/2002

This paper presents a proposal of classification of the engine room simulators. Its main subject is the relation between proposed simulator types and the learning objectives specified in the STCW International Convention.
It was also proved that in some cases the full mission simulator is not the best tool for the specific training tasks. Finally, the problem of simulator compliance with the provisions of STCW International Convention was discussed.
(POLISH MARITIME RESEARCH, No 1/2002)

        In the paper a model of heat exchange in the diesel engine cylinder - environment system was presented together with its application to 6ZA40S engine. The model, a component of the general model of energy transformation process in the engine, makes it possible to calculate instantaneous values of heat flow through cylinder walls. It can operate in real time mode within the entire range of engine load.
The model was verified by comparing the simulation results and data from engine bed test measurements as well as by assessing time course correctness of selected working parameters.
(POLISH MARITIME RESEARCH, No 1/2002)

Model tests of the Catenary Anchoring Leg Mooring (CALM) systems are often carried out in elongated tanks which makes it necessary to significantly distort catenary of the anchoring chains, and causes a complication when checking test results by numerical models, or alternatively - to reduce the model scale which leads to increasing scale effects.
In the paper a new model testing arragement is presented where all chains are placed in planes parallel to the tank axis which makes numerical calculations easier and modelling the system in a greater scale possible.
(POLISH MARITIME RESEARCH, No 1/2002)

In the paper different design solutions of refrigerating systems are considered, which are applicable to the universal refrigerated ships employed in shipping of refrigerated cargo within a wide range of temperature.
The example systems are analyzed and compared to each other with the use of the exoergic efficiency criterion. Example calculations of defrosting cycle influence on the exoergic efficiency of both analyzed systems are also presented.
(POLISH MARITIME RESEARCH, No 1/2002)

The paper presents the design of PID ship course-keeping autopilot of high steering performance and which is robust against ship dynamic motion variations. The basis for the design was a simple linear model of ship dynamic motion, but model's variations due to velocity were also considered.
The PID controller coefficients were selected by using the performance indices: the settling time and ITAE integral performance index. The designed PID controller was tested by means of computer simulations. For that aim a nonlinear, directionally unstable ship model was used.
(POLISH MARITIME RESEARCH, No 1/2002)

No 2/2002

This paper deals with fatigue assessment of metal beams under complex loading. Combined axial, bending and torsion loads are taken into account under assumption that the material complies with the Kelvin-Voigt's model and has a fatigue limit, and the stress components are stationary stochastic processes which are stationary correlated and differentiable in the mean-square sense.
By taking the power spectral densities of the stress components for known the criterion of infinite fatigue life of beams is formulated in the frequency domain. For this purpose the distortion-energy strength hypothesis and the theory of energy transformation systems are used.
(POLISH MARITIME RESEARCH, No 2/2002)

In this paper an attempt is presented to analyze real possibilities of safe evacuation of the casualties of marine accidents with the use of the Free-Fall Lifeboats (FFL). Major impediments are discussed and proposals of the relevant amendments to the current regulations are outlined.
The influence is analyzed of the dynamic behaviour of the FFLs on the casualties placed on a stretcher and differently located within the lifeboat. On the basis of the evacuation scenario some practical conclusions have been worked out leading to recommendations for safe evacuation of the casualties of marine accidents.
(POLISH MARITIME RESEARCH, No 2/2002)

In the paper assumptions for turbine seal modelling as well as the calculation results of the motion stability of a great-output turbo-set rotor are presented. The flow equation system was solved by using the linear perturbation method. On calculation of pressure distribution in the seal chambers it was possible to estimate values of the forces affecting the rotor in the seals.
Problems of turbo-set rotor dynamics were solved with the use of the transfer matrix method where influences of partial turbo-set systems (bearing oil film, foundation, turbine seals) were modeled by dynamic characteristics dependent on rotor rotational speed and vibration frequency. The theoretical results were partly confirmed by experimental investigations.The calculation results presented in the paper have been a part of the more thorough analysis of the great-output, energy-plant turbo-set [17,18].
(POLISH MARITIME RESEARCH, No 2/2002)

In the paper a non-linear model of hydraulic flow network as well as a way of its numerical solving is presented. The proposed flow network model can be applied to real-time simulation. In order to verify the model the simulation of main engine auxiliary systems was performed.
(POLISH MARITIME RESEARCH, No 2/2002)

The paper presents research aimed at implementation of Polish soda lime (produced by Chemical Company Oświęcim) as the absorbent in carbon dioxide canisters of Oxy-NG diving apparatus.
Results of this work were presented during Annual Meeting of Underwater Diving Working Group, NATO Standardization Agency, held at US Navy Experimental Diving Unit, Panama City, USA.
(POLISH MARITIME RESEARCH, No 2/2002)