Accession Number : AD0736631

Title :   The Skin Friction of a Hydrofoil Near a Free Surface.

Descriptive Note : Technical rept.,

Corporate Author : MICHIGAN UNIV ANN ARBOR DEPT OF NAVAL ARCHITECTURE AND MARINE ENGINEERING

Personal Author(s) : Gebhardt,John C.

Report Date : OCT 1968

Pagination or Media Count : 204

Abstract : 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. (Author)

Descriptors :   (*SKIN FRICTION, *HYDROFOILS), BOUNDARY LAYER, SURFACES, LAMINAR FLOW, PRESSURE

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE