ON AN ESTIMATION METHOD FOR PROPELLER EXCITING FORCE AND ITS APPLICATION-DEVELOPMENT OF FOUR BLADED PROPELLER WITH UNEQUAL ANGLES

To reduce the vibration of a hull that resonates with the second unbalanced moment of a main engine, a four-bladed propeller with un-equal angles between the blades, inducing the even order component of the bearing force, has been designed. When this propeller is installed with an apropriate phase lag for the exciting effect of the engine, the second components of the propeller and engine are counterbalanced and hull vibration is reduced. In this study of the development of such a propeller, the Author proposes a simple method for estimating the bearing forces in an effective wake. The method, which uses data from self-propulsion tests and the nominal wake pattern, is applied to a tanker and a cargo-ship, and the thrust variation is compared with results of model experiements and those from Kumai's method. The bearing force of four-bladed propellers with unequal blade-angles is then determined in this way. On the basis of sea trials and the bearing force determined by this method, the possible reduction, by a half, of the second order component of hull vibration of a 10,000-dwt cargo-ship at resonance frequency if a four-bladed propeller with unequal blade-angles is fitted, is discussed. Order form BSRA as No. 51,911.

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  • Corporate Authors:

    Kansai Zosen Kyokai, Osaka University

    Aza-yamadaue, Suitashi
    Osaka,   Japan 
  • Authors:
    • Yamaguchi, M
  • Publication Date: 1979-6

Language

  • Japanese

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00303886
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Feb 27 1980 12:00AM