THE SKIN FRICTION OF A HYDROFOIL NEAR A FREE SURFACE

The effect of the free surface on the viscous boundary-layer around a two-dimensional hydrofoil is investigated both theoretically and experimentally. The methods of Giesing and Smith are used to calculate the potential flow for a hydrofoil moving near a free surface. This potential flow is then used as a basis for calculating the laminar boundary layer, transition and the turbulent layer. The calculations indicate that while the free surface affects the laminar skin friction near the nose of the foil strongly, the effect of Froude number and depth on the average skin friction coefficient is negligible, even for small depths and large Froude numbers. Experiments to measure the pressure distribution on both top and bottom surfaces of the foil, together with the wave patterns at several depths and Froude numbers are described.

• Corporate Authors:

  University of Michigan, Ann Arbor

  Department of Naval Architects and Marine Engineers
  Ann Arbor, MI  United States  48109
• Authors:
  • Gebhardt, J C
• Publication Date: 1968-10

Media Info

• Pagination: 204 p.

Subject/Index Terms

• TRT Terms: Boundary layer; Free surface; Froude number; Hydrofoils; Potential flow; Skin friction
• Old TRIS Terms: Boundary layer theory; Effects; Free surface effects
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00033633
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: 109 Tech Rpt, 08368-1-F
• Contract Numbers: N0014-67-A-01310002
• Files: TRIS
• Created Date: Aug 15 1972 12:00AM