THE SMALL FROUDE NUMBER PARADOXES AND WAVE RESISTANCE AT LOW SPEEDS

Two basic asymptotic expansions of the equations of two-dimensional free-surface gravity flow past a body are first discussed: (i) the thin body, and (ii) the naive small Froude number expansions. It is shown that different solutions are obtained for small Froude number and thin body from (i) and (ii) (the first paradox), because (ii) is not uniform in the downstream region of the flow domain, where waves are concentrated. Moreover, the thin body expansion, which leads at first order to the usual linearized wavemaking approximation, is not uniform as the Froude number tends to zero (the second paradox). By using the exact solution of a model problem, linearized free-surface conditions leading to uniform small Froude number solutions have been derived.

• Corporate Authors:

  Hydronautics, Incorporated

  7210 Pindel School Road
  Laurel, MD  United States  20810
• Authors:
  • Dagan, G
• Publication Date: 1972-6

Media Info

• Pagination: 65 p.

Subject/Index Terms

• TRT Terms: Free surface; Froude number; Two dimensional flow; Wave resistance
• Old TRIS Terms: Effects; Free surface effects
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00040932
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: TR-7103-4 Tech Rpt
• Contract Numbers: N00014-71-C-0080
• Files: TRIS
• Created Date: Feb 23 1973 12:00AM