• Title/Summary/Keyword: Low-speed full ship

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An Experimental Study on the Characteristics of Propeller and Rudder in Oblique Towing Conditions (사항상태(斜航狀態)에서 프로펠러와 타(舵)의 특성(特性)에 관한 실험적 연구)

  • S.K. Lee;H.S. Kim;S.J. Kim;M.J. Song;S.H. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.4
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    • pp.66-72
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    • 1994
  • For the reliable prediction of maneuverability of a ship, lots of captive model tests have been carried out for over 10 years. But the parameters appearing in the mathematical model are so versatile and showing complex characteristics, and it is still hard to establish the useful formulae that we can adopt directly in the design stage. In this paper, the most important parameters in the mathematical model. i.e.($1-\omega_P$) the effective wake fraction at propeller, and $\delta_R(\beta_R)$), the effective rudder inflow angles are investigated by the captive model tests at the circulating water channel. The model is tested at designed speed and at low speed, and the drafts at both full load and ballast load conditions are taken. Propeller thrusts and rudder normal forces are measured at the given drift angle and propeller revolution. These forces are used for the analysis of the effective flow velocity or flow direction, to the propeller or rudder.

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Comparison of emission characteristics between fuel injection systems with echanical cam and electric control type on low speed 2 stroke diesel engine for ship propulsion (선박추진용 기계적 캠 구동식 및 전자제어식 연료분사 시스템을 가진 저속 2행정 디젤엔진의 배기특성 비교)

  • Lee, Sang Deuk;Koh, Dae Kwon;Jung, Suk Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.6
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    • pp.611-616
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    • 2013
  • Many researches have been carried out consistently for the green ship owing to its economic increasement, efficiency and convenience. One of them is an electronic controlled marine diesel engine. However, we are suffered from dissemination of above engine, due to its anxiety about safety and reliability. In order to solve these problems in this study, emission characteristics test of main propulsive two-stroke diesel engine, equipped both electronic control and cam drive fuel injection systems, has been performed and evaluated under the various load conditions. From the test results, we have confirmed that exhaust gas emission characteristics of the electronic control system is similar to the cam drive system in eco-mode operation, but NOx in emission mode has been decreased 100ppm or more in full load condition. HC emission from the electronic control system is decreased 10~20ppm at 50% load, and 35~40ppm at 25% load in comparison to cam drive system. In fuel consumption, it is considered that 7g/kWh is decreased than the value of cam drive system at 700bar of injection pressure, which is 200bar higher than cam drive system.