界面活性剤水溶液中の円柱の抵抗減少効果に関する研究(流体工学,流体機械)
2003 年 69 巻 687 号 p. 2424-2430
詳細
2003 年 69 巻 687 号 p. 2424-2430
The flow around a circular cylinder in surfactant solution was investigated in the Reynolds number range of 6000 to 50000 in several ways : by measuring the pressure around the cylinder, by visualizing flow and by measuring the velocity profiles in the wake. The test fluids were aqueous of the surfactant Oreyl-bishydroxyethyl-methyl-ammonium (trade name : Ethoquad O/12) with sodium salicylate added as a counterion. The pressure coefficient of surfactant solutions at the back of the cylinder was larger than that of tap water for Reynolds number above 6000. The separation point of surfactant solutions moves downstream, and the angle increases with surfactant concentration. The width of the velocity defect in the wake of surfactant solutions was less than that of tap water. For Reynolds number above 6000, a maximum drag reduction approximately 35% occurred with the surfactant solutions.
