An experimental investigation is to be carried out to explore one particular mechanism of drag reduction through polymer additives in liquids. This is the effect of the additive on streamwise, counter- rotating vortices near the wall. These are hypothesised to interact with concentrated polymer threads. The configuration to be utilized will be the annular gap between concentric rotating cylinders. Fluoresecnt dye and two-component Laser-Doppler anemometry will be used as diagnostic tools over a range of Reynolds number and rotation rates.
