DESIGN OF BULBOUS BOWS

There is no doubt that bulbous bows improve most of the properties of ships, but the correct design and power prediction for ships with bulbous bows are still difficult due to the lack of design data. In the paper, a quantitative design method is presented together with the necessary data providing relationships between performance and main parameters of ships and bulbs. The data, in the form of design charts, are derived from a statistical analysis of routine test results of the Hamburg and the Berlin Model Basins, HSVA and VWS, respectively, supplemented by results of additional tests to fill the gaps. Three main hull parameters are taken into account: block coefficient, length/beam ratio, and beam/draft ratio, while six bulb quantities are selected and reduced to bulb parameters, of which the volume, the section area at the fore perpendicular, and the protruding length of the bulb are the most important. For power evaluation, the total power is subdivided into a frictional and a residual part. Depending on bulb parameters and Froude number for each block coefficient of the main hull, six graphs of residual power reduction have been prepared. Because of the wide range of block coefficients, there are so many design charts that only one example is presented herein.

  • Supplemental Notes:
    • Paper presented at SNAME Annual Meeting, November 16-18, 1978.
  • Corporate Authors:

    Society of Naval Architects and Marine Engineers

    601 Pavonia Avenue
    Jersey City, NJ  United States  07306-2907
  • Authors:
    • Kracht, A M
  • Publication Date: 1978-9

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Filing Info

  • Accession Number: 00184808
  • Record Type: Publication
  • Source Agency: Society of Naval Architects and Marine Engineers
  • Report/Paper Numbers: Paper No. 7
  • Files: TRIS
  • Created Date: Jan 13 1979 12:00AM