EXPERIMENTAL INVESTIGATION ON DRAG REDUCTION OF MIXED PEO AND CTAC/NASAL AQUEOUS SOLUTION IN A ROTATING DISK APPARATUS

Drag reduction (DR) by the additive of mixed surfactant and polymer is investigated in detail in a rotating disk apparatus (RDA). Polyethylene oxide (PEO) and Cetyltrimethyl ammonium chloride (CLAC)/sodium salicylate (NaSal) are chosen as polymer and surfactant, respectively. It is investigated on the influence of combination concentration of polymer & surfactant, temperature and Reynolds number on the drag-reducing rate. The present experimental results show that the drag-reducing rate of the mixed solution is definitely higher than that of the pure PEO or CTAC/NaSal solutions. This phenomenon is especially sharp at the high temperature andior the large Reynolds number. When the temperature is higher than 30 degrees C, the net enhancement of DR is the sharpest for the mixed solutions of any CTAC/NaSal concentration and 30 ppm PEO. However, for the mixed solutions of the fixed PEO concentration, the combination concentration of PEO & CTAC/NaSal, which causes the sharpest enhancement of the DR, depends on temperature. In short, comparing with the only addition of PEO or CTAG/NaSal, the coupled addition of PEO & CTAC/NaSal can obtain the very good drag-reducing effect for the rotating disk apparatus at the high temperature and/or the great Reynolds number.