CALCULATION OF THE MANEUVERABILITY OF FAST WATER-DISPLACING SHIPS

New relationships for the coefficient of the transverse force and of its moment on the hull of the ship carrying out a steady turn are presented. A good agreement has been established between the experimental data following a more complete accounting of the influence of the speed with which the ship enters the turn. The magnitude of the ships motion is limited by transition to a skimming motion. The calculation of the transverse force is carried out using the hypothesis of plane sections. The shape of the diametric ship surface is approximated by a polygon, thus simplifying the calculational part. In the work the author used experimental data determining the correction to the moment and taking into account the negative load in the region of the undercut of the stern deadwood. Relationships for the determination of the gradient of the transverse force and the gradient of the moment are given. An analysis of the influence of trim on the stability of the ships course was carried out. The presence of angular velocities and drift angle increases substantially the trim angle and the sagging of the ship relative to the values encountered during straight motion. A formula for the calculation of the nonlinear parts of the transverse force and momentum coefficient are given. By taking into account the nonlinearity of these coefficients due to resistance to the transverse flow on the ribs, one finds their quadratic dependence on the parameters of motion, while taking into account the influence of the free surface of the liquid yields a cubic dependence. An equation for the calculation of the transfer rolling forces is also obtained and its graphical solution is given. A sharp decrease in the angular velocity (the increase in circulation radius) is encountered within the 0.3 less than F less than 0.5 range. With a further increase in speed the circulation radius changes only a little.

• Corporate Authors:

  Trudy Leningrad Korablestroitelnyy Instituta

  Leningrad,   USSR 
• Authors:
  • Sobolev, G V
• Publication Date: 1966

Media Info

• Pagination: p. 143-154
• Serial:
  • Publication of: Trudy Leningrad Korablestroitelnyy Instituta
  • Issue Number: n25
  • Publisher: Trudy Leningrad Korablestroitelnyy Instituta

Subject/Index Terms

• TRT Terms: Maneuverability; Moments (Mechanics); Rolling; Ship motion; Stability (Mechanics)
• Old TRIS Terms: Rolling moment
• Subject Areas: Marine Transportation; Materials; Vehicles and Equipment;

Filing Info

• Accession Number: 00014909
• Record Type: Publication
• Source Agency: Joint Publications Research Service
• Files: TRIS
• Created Date: May 7 1973 12:00AM