On-the-water Measurement of Laminar to Turbulent Boundary Layer Transition on Sailboat Appendages
Achievement of laminar boundary layer flow over sailboat appendages offers great potential for increased boat speed. Although some measurements of turbulence intensities and length scales in the upper ocean are available, it is unclear whether the local effects of wave action, high particulate content, and boat motions, would prohibit the development of large runs of laminar flow. In order to determine whether laminar boundary layers routinely develop at full-scale conditions, the laminar-toturbulent boundary layer transition region was measured on the keel fin and bulb of a sailboat going upwind, downwind, and under tow. The experimental approach described in this paper will be useful for the development and evaluation of various seawater drag reduction methods.