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H. Mehdigholi, H. Rafsanjani and Behzad Mehdi

.: Damage mechanics approach for bearing lifetime prognostics , Journal of mechanical systems and signal processing, Vol. 16 No. 5, pp. 817-829, 2002 Li Y., Kurfess T., Liang S.: Stochastic prognostics for rolling element bearings , Journal of mechanical systems and signal processing, Vol. 14 No. 5, pp. 747-762, 2000 Lemaitre J., Desmorat R.: Engineering Damage Mechanics , Springer-verlag, Berlin, 2005.

Open access

Jianguang Zhao and Jingjing Fan

Sunil Vidya Bhooshan. Lifetime Optimization of a Multiple Sink Wireless Sensor Network through Energy Balancing .Journal of Sensors Volume 2015, Article ID 921250, 6 pages 4. Jiliang Wang, Wei Dong, Zhichao Cao, and Yunhao Liu. On the Delay Performance in a Large-Scale Wireless Sensor Network: Measurement, Analysis, and Implications. IEEE/ACM TRANSACTIONS ON NETWORKING, 5. Gabriel Mujica, Jorge Portilla, Teresa Riesgo. Performance evaluation of an AODV-based routing protocol implementation by using a novel in-field WSN diagnosis tool . Microprocessors

Open access

Wojciech Homik

Diagnostics, maintenance and regeneration of torsional vibration dampers for crankshafts of ship diesel engines

Periodically changeable gas and inertia forces which occur during operation of engine generate transverse, axial and torsional vibrations of crankshafts of multi-cylinder combustion engines. Torsional vibrations are those which endanger crankshafts of multicylinder combustion engines the most. In order to minimize their impact a torsional vibration damper is installed at crankshaft's free end. Its technical state directly influences lifetime and reliability of engine. In this paper methods of diagnosing, maintenance and regeneration of torsional vibration dampers used in shipbuilding, are discussed. Also, are presented results of multi-year statistical investigations carried out in cooperation with a firm maintaining and regenerating ship engine torsional vibration dampers, which illustrate types of failures occurring in viscous and spring torsional vibration dampers.

Open access

Zdzisław Stelmasiak, Jerzy Larisch, Jacek Pielecha and Dariusz Pietras

Abstract

The paper presents the results of examination of particulate matter emission from the Diesel engine FPT 1.3 MJT simultaneously fuelled with diesel oil and natural gas CNG. The basic premise for engine adaptation was the addition of a small amount of CNG to reduce exhaust gas opacity and particulate matter emission. At this assumption, diesel oil remained the basic fuel, with contribution amounting to 0,70-0,85 of total energy delivered to the engine. The dual fuel engine was examined using an original controller installed in the Diesel engine FPT 1.3 MJT which controlled the diesel fuel dose. The dose of the injected natural gas was controlled by changing the opening time of gas injectors at constant pressure in the gas collector. The examined issues included the exhaust gas opacity, and the total number and fractional distribution of the emitted particles. The measurements were performed at twenty selected measuring points corresponding to the New European Driving Cycle (NEDC) test. The performed tests have demonstrated a positive effect of gas addition on exhaust gas opacity and particulate matter emission. Depending on test conditions, the exhaust gas opacity was reduced by 10÷92%, and the total number of particles by 30÷40%. The performed tests have revealed that a small addition of gas can reduce the load of the DPF filter, extend its lifetime, and increase engine reliability. Longer time intervals between successive DPF filter regenerations improve ecological properties of the engine.

Open access

Leszek Matuszewski

Abstract

The article analyses properties of magnetic fluid seals installed in rotary sealing nodes which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals exposed to longterm utility water loads, at different water pressures and shaft revolutions. The basic seal durability criterion was the number of revolutions made by the sealing node shaft until the appearance of water tightness loss (leakage). It was found that the main factor leading to the wear of the seal is the relative speed of the magnetic fluid with respect to that of the utility water, and this process is heavily affected by the pressure acting on the seal. The reported test results are presented in the form of diagrams showing the seal durability (time until water tightness loss) as a function of rotational speed. The curves shown in the diagrams are regular, with two different rotational speed ranges: the highspeed range, when the tightness loss is relatively fast, and the low-speed range, with a clear tendency to prolong the seal lifetime. These diagrams were given the name of durability curves of the MF seal operating in water. The results of the performed tests suggest formal similarity between the experimental data distribution concerning tightness loss processes occurring in magnetic fluid seals operating in water environment and metal fatigue processes. The article proposes a preliminary simplified durability model to describe the examined phenomenon.

Open access

Piotr Bzura

lubricating oil quantity and quality on operational correctness of crankshaft slide bearings (in Polish. Publishing House of Maritime Academy of Szczecin, Szczecin 2016, pp.30-36. 7. Beek A. V.: Machine lifetime performance and reliability , TU Delft, Delft, 2004. 8. Rudnicki J.: Evaluation of compression realization in diesel engine based on performance indicator changes. Journal of Polish CIMEEAC, Vol. 7, No. 1, Gdańsk 2012 9. Designation: ASTM D5183 – 05(2016) Standard Test Method for Determination of the Coefficient of Friction of Lubricants Using

Open access

Leszek Knopik, Klaudiusz Migawa and Andrzej Wdzięczny

14. Kleyle, R.M. and Dahiyam R.L.: Estimation of parameters of mixed failure time distribution from censored data, Communications Statistics, Theory and Method, vol. 4, pp. 873−882, 1975 15. Knopik, L.: Mixture of distributions as a lifetime distribution of a technical object, Scientific Problems of Machines Operation and Maintenance, vol. 45, 2(165), pp. 53−60, 2010 16. Knopik, L.: Model for instantaneous failures, Scientific Problems of Machines Operation and Maintenance vol. 46, 2(166), pp. 37−48, 2011 17. Knopik

Open access

Andrzej Banaszek, Zbigniew Łosiewicz and Wojciech Jurczak

Science, 49 (2007) pp.4308-4338 17. Mannesmann Rexroth GmbH, Vademecum of hydraulics. Volume 3, Design and structure of hydraulic systems (in Polish). Mannesmann Rexroth Verlag (Polish edition), RPL 00281/10.88, Lohr a. Main, Germany 1992 18. Hobbit, Karlsson, Soersen Inc.: ABAQUS ver.6.7 User’s manual, Pawtucket, USA 2006 19. Stocznia Szczecinska SA: Technical documentation of B578-I/542-1 (Shipyard internal materials) (in Polish), Szczecin 1997 20. Kucheryavyi V. I., Mil’kov S. N.: Probabilistic prediction of the residual lifetime of a gas

Open access

Henryk Tomaszek, Mariusz Zieja and Mariusz Ważny

aircraft operation (in Polish). Wydawnictwo Naukowe Instytutu Technologii Eksploatacji, Warszawa 2008. 21. Woch M., Kurdelski M., Matyjewski M.: Reliability at the checkpoints of an aircraft supporting structure. Eksploatacja i Niezawodnosc – Maintenance and Reliability. Vol. 17, No 3, 2015, pp. 457 – 462. 22. Żurek J., Tomaszek H., Zieja M.: Analysis of structural component’s lifetime distribution considered from the aspect of the wearing with the characteristic function applied. Safety, Reliability and Risk Analysis: Beyond the Horizon. CRC Press

Open access

Jerzy Girtler

.: Background for stochastic model of friction wear in issues of lifetime of machine elements (in Polish). Zeszyty Naukowe, Mechanika, No. 19, Politechnika Radomska 1989. 26. Piotrowski I.: Ship combustion engines (in Polish). WM, Gdańsk 1971. 27. Piotrowski I., Witkowski K.: Operation of ship combustion engines (in Polish). Maritime Academy, Gdynia, 2002. 28. Plewiński L.: Accidents at sea. Collisions of ships (in Polish). Publ. WSM, Szczecin, 2000. 29. Rozanov Ju.A.: Stacionarnye slučajnye processy (in Russian