Session MA - Turbulent Boundary Layers V.
MIXED session, Tuesday afternoon, November 23
Grand I, Westin Seattle
Skin friction constitutes a considerable proportion of the total drag on a ship. The flow mechanisms giving rise to friction drag occur mostly in a thin region near the solid surface. A HIgh Reynolds number, smooth, flat PLATE (HIPLATE) model is used to conduct equilibrium boundary layer experiments at scales approaching prototype applications. The plate measures 3 m wide by 12.9 m long, and Reynolds numbers (based on downstream distance) of 200 million have been achieved. This talk reports on a friction-drag-reduced flow study by means of injecting long-chain, water-soluble polymer into the boundary layer. We describe the details of a particle imaging velocimetry (PIV) system to measure the mean and fluctuating velocity profiles in the inner region of the boundary layer (y < 2 mm, or y+ < 400), with a vector spacing of approximately 40 microns. A laser induced fluorescence (LIF) system is also used to measure the mean and fluctuating concentration profiles of the injected polymer. Preliminary results are discussed. [Sponsored by DARAPA]