Many surfactants and polymers are considered as excellent drag reducing agents. This phenomenon induces a significant head loss reduction compared to the pure solvent. In this study an aqueous solution of CTAC/NaSal (CetylTrimethyl Ammonium Chloride and Sodium Salicylate) is used in turbulent pipe flow system. Drag reduction experiments were carried out for different experimental conditions using pressure drop measurements. At the same time the spatial velocity distribution was measured and analysed using particle image velocimetry (PIV). 德國LaVision PIV/PLIF粒子成像測速場儀 Imager LX PIV相機 用于粒子成像測速(PIV)的熒光示蹤粒子