Drag reduction of a small, man deployable buoy

Abstract

This paper is adapted from a Masters thesis completed by the author. Experimental wind tunnel studies were conducted in an attempt to reduce drag over a cylindrical buoy at low Reynolds numbers. Two high thickness to chord ratio sections were tested to determine their aerodynamic coefficients, aerodynamic centers, and stability about the mooring point. Results indicate that drag reduction on the order of 75 to 90% over the tested range of velocities is possible. Although promising, drag and stability results come with important caveats. One fairing section was found to be unstable if held at the thickest section, while demonstrating the best drag performance. The other section is sensitive to surface conditions and Reynolds number effects, yet is fully stable and has a compact form. Engineers are left with important decisions: attempt to stabilize the low drag section and realize the largest drag benefits, or use the stable section and accept higher drag for a more compact package. Although both solutions have associated risks, large performance gains and reduced costs are possible.