PARTIAL FORM FACTORS FROM EQUIVALENT BODIES OF REVOLUTION FOR THE FROUDE METHOD OF PREDICTING SHIP RESISTANCE

The role of partial form factors is described in improving the Froude method of extrapliating the resistance measurements of ship models to full-scale conditions. "Partial form factors" convert the equivalent flat-plate resistance into the part of the viscous resistance of ship hulls which varies with Reynolds number. In contrast, "whole form factors," sometimes called Hughes form factors, convert the equivalent flat-plate resistance into a viscous resistance which varies completely with Reynolds number. The use of a partial form factors results in a full-scale resistance less than that predicted by the traditional method of zero form factor and greater than that predicted by the whole form factor (Hughes) method. It is advocated that partial form factors tailored to the particular ship be obtained from boundary-layer calculations of the viscous resistance of equivalent bodies of revolution. Some numerical examples are given and a rough correlation of calculated partial form factors with hull geometry is also presented.

  • Supplemental Notes:
    • Presented at the First Ship Technology and Research (STAR) Symposium, Washington, D.C., August 26-29, 1975.
  • Corporate Authors:

    Society of Naval Architects and Marine Engineers

    601 Pavonia Avenue
    Jersey City, NJ  United States  07306-2907
  • Authors:
    • Granville, P S
  • Publication Date: 1975-8

Media Info

  • Features: References;
  • Pagination: 8 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00126937
  • Record Type: Publication
  • Source Agency: Society of Naval Architects and Marine Engineers
  • Report/Paper Numbers: #9
  • Files: TRIS
  • Created Date: Nov 5 1975 12:00AM