This publication comprises a summing up of available pro- cedures for the estimation of propeller induced excitation forces and a critical examination of their ability to assess such forces acting on the ship. Reasons are given why hull wakes cannot be applied for estimation of cavitation performance and hull forces without correction for scale, propeller induction effects and operation in waves. Methods are suggested for estimation of such effects. By the concept of equivalent wake it is shown that the propeller induction effects for the test case considered does not alter the hull wake with propeller blade in vertical upwards position. Means are illustrated by which the propeller may transfer large amounts of energy to the hull under conditions for cavitation inception. It is demonstrated that the blade frequency part of the forces may be properly assessed by direct application of hull wakes only. The random part of the wake, however, needs to be included by application of statistical methods. Most of the methods discussed appear to be able to provide us with reasonable results at the projecting stage if the wake input to the computer resembles the velocity distribution actually experienced by the propeller.

  • Corporate Authors:

    Scandinavian Ship Technical Society

    Radhusgt 8, Box 162
    Oslo,   Norway 
  • Authors:
    • Sontvedt, T
  • Publication Date: 1971-5

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 3-21
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00028767
  • Record Type: Publication
  • Source Agency: United States Merchant Marine Academy
  • Files: TRIS
  • Created Date: Mar 28 1972 12:00AM