In order to investigate the wake distribution of full ships, the measurement of the flow around the stern of a 200,000 DWT tanker together with its two model ships, 7m and 30m models respectively, was carried out using 5-hole spherical Pitot tubes. For both the ship and its 30m models, the measured section was forward to the propeller at a distance of 90% of the propeller diameter, while the 7m model was measured at several additional points, besides the foregoing allocation. In addition to these experiments, a detailed study of stern flow through boundary layer measurements of the 7m model was conducted with a 3-hole arrow type Pitot tube. The pressures through the 5-hole and 3-hole Pitot tubes were measured using autobalacing pressure transducers and a digital record system. The boundary layer measurement revealed the flow in the vicinity of the hull surface, the mechanism and growing process of the bilge vortex. From the wake measurement it was proven that the complicated flow, otherwise known as a bilge vortex, exists in a ship's wake as well as in its model wake, and a method of estimating the wake distribution of ships from their model is also applicable to full form ships. Moreover, when this method is applied to the estimation of the flow direction of a ship's wake, the estimated direction will prove itself to be in fairly close agreement with the experimental values.

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  • Corporate Authors:

    Ishikawajima-Harima Heavy Industries Co., Ltd.

    2-16, Toyosu 3 Chome, Koto-Ku
    Tokyo 135,   Japan 
  • Authors:
    • Namimatsu, M
    • Muraoka, K
  • Publication Date: 1974-9

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Filing Info

  • Accession Number: 00072525
  • Record Type: Publication
  • Source Agency: Ishikawajima-Harima Heavy Industries Co., Ltd.
  • Files: TRIS
  • Created Date: Dec 19 1974 12:00AM