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Identification of ship propeller torsional vibrations

Rosłanowski J.

Journal of KONES

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2015

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Vol. 22, No. 2

177--184

EN

The article presents identification methods of ship propeller torsional vibrations in dimensional space and ways for their dumping. Propeller torsional vibrations are caused by static, dynamic and hydrodynamic unbalance of propeller itself and its operation in non-uniform velocity field of ship hull. The propeller working in uneven velocity field of the hull creates cyclic thrust forces, peripheral vibrations of shaft as well as flexural and torsional load of propeller shaft. Vibrations cause additional thrust load on shaft bearings and shaft bending moment. Vibrations of ship hull, particularly its stern section cause variation of pressure field created by propeller. Amplitude of particular parts of the hull comes from the action of cyclic forces created by working ship propeller. They can be very large. Therefore, the ways to reduce vibrations caused by running propeller are very important. Given in the article methods of vibration dumping calculations conduct to determination of vibration dumping coefficients. Calculation results are comparable to measuring results in spite of fact they were determined under assumption of different velocity fields of water flowing through propeller circle. Amplitudes of vibrations depend on number of propeller blades and pulsate with the basic frequency equal to product of the rotational speed and number of blades. Causes of such vibrations and additional load of vessel stern are described in the article. An attention was paid to assure the greatest possible uniformity of velocity field by adequate design of stern shape and accessories. The ways to reduce torsional vibrations of propeller by the appropriate selection of blades number and their accurately machining are also given in the article.

2

Parametric functions of ship propulsion engine operation

Roslanowski J.

Journal of KONES

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2010

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Vol. 17, No. 4

407-413

EN

The following article presents the method of determining the ship 's propulsion engine operation basing on the engines work parameters by means of dimensional analysis. The operation of engine is considered as effective energy transfer to ship propeller in the form of work during its operation. According to Girtler engine operation can be considered as, a new physical quantity of dimension Joul multiplied by second [2, 3J. A random type of combustion in engine cylinders makes possible to deal with engine operation as a random variable vectors in the Hilbert space isomorphic with dimension space. The analysis of stochastic engine workprocess is alternatively used as a set of determinist time functions by means dimension analysis. Parametric functions of engine work were determined on the basis of algebraic analysis scheme designed by S. Drobot. This scheme makes possible to control the correctness of conclusion rules regarding mathematics in digital functions describing operation of ship propulsion engine. Additionally the parametric form of function makes possible to investigate the influence of function parameters on correctness of engine operation. It makes possible to forecast the engine operation i given sailing conditions and to estimate steerability of ship during the voyage. It improves the safety of ship operation propelled by single engine propulsion plant.

3

Badania oleju smarowego metodą spektroskopii absorpcyjnej w podczerwieni

Litwiński M., Piec P.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2006

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z. 1/60

151--156

PL

Praca dotyczy badań oleju smarowego metodą spektroskopii absorpcyjnej w podczerwieni. W badaniach tych wykazano wpływ czasu eksploatacji silnika spalinowego na zmiany wartości absorpcji badanego oleju. W pracy zamieszczono, w formie wykresu, wybrane wyniki badań spektrometrycznych w podczerwieni określonych próbek oleju smarowego. Przedstawione w pracy wyniki badań oleju stanowią punkt odniesienia w aspekcie analizy wpływu warunków pracy badanego środka transportu na zmianę charakterystyki spektrometrycznej w podczerwieni. Analiza eksploatacyjnych warunków pracy prowadzona jest za pomocą programu komputerowego typu Volvo ROADRELAY.

EN

The paper concern the investigation of lubrication oil with infra-red absorption spectroscopy method. In this investigation the technical operation time influence of combustion engine on the absorption value change of investigated oil has been showed. In this paper, in graph form, choosen results of infra-red absorption spectroscopy investigation of lubrication oil samples have been presented. The investigation results of lubrication oil, presented in the paper, make the point in analysis aspect of means transportation work condition influence on the change of infra-red absorption spectroscopy characteristic. Analysis of operational work condition is performed by computer program of type Volvo ROADRELAY.