非イオン性界面活性剤水溶液の抵抗低減効果(流体工学,流体機械)

抄録

There are a few studies on the drag-reducing effect of nonionic surfactant solutions which are nontoxic and biodegradable, while a lot of investigations for cationic surfactant solution have been performed so far. First, the drag-reducing effects of nonionic surfactant solutions such as oleyldimethylamineoxide (ODMAO) and alkyl polyglycoside (APG) were investigated by measuring the pressure drop in the pipe flow. Second, we investigated the drag-reducing effect of a nonionic surfactant on the turbulent boundary layer using a two-component laser-Doppler velocimetry (LDV) and particle image velocimetry (PIV) systems. At the temperature of nonionic surfactant solutions T=25℃, the maximum drag reduction ratios for ODMAO 500ppm and APG 6000ppm were about 50% and 15%, respectively, in the boundary layer flow, although the drag reduction ratio for both surfactant solution was larger than 60% in pipe flow. Turbulence statistics and structures for ODMAO 500ppm showed the behavior of typical dragreducing flow such as suppression of turbulence and modification of near-wall vortices, while velocity fields for APG 6000ppm were similar to those of water.