Drag Reducing Effect of Surfactant Solution on a Piping System and its Application for Saving Energy Consumption

本课题的目的是阐明表面活性剂溶液在管道系统中具有显著减阻作用的流动机理。为了达到这一目的，我们制作了一根直圆形截面管和曲率比（弯曲曲率除以管道内半径）为4的弯头的实验装置，并进行了流变特性研究、压力测量和WV测量。最后，我们试图解释与这些结果相关的药物减少作用。这些将对新的药物还原技术的创新有价值。流变特性研究结果表明，我们研究的表面活性剂溶液（LSP-01M）也可以成为许多表面活性剂溶液中常见的剪切诱导态（SIS）。在直管实验中，阐明了表面活性剂溶液中边界层的发展过程。我们还发现，在质量浓度为50 ppm时，随着雷诺数的增加，最大dr…More ug还原率超过70%，药物还原效果并未完全消失。给出了壁面坐标系下的速度分布。进行了详细的速度测量，通过对向外相互作用和抛射、向内相互作用和扫掠的概率密度函数的对称分布进行细化，抑制了轴向和径向速度波动的相关性——雷诺剪应力。还发现离壁稍远的表观黏度与SIS相吻合，且在壁附近存在较小的表观黏度区域。利用表观黏度梯度解释了抑制雷诺数剪切应力的原因。在弯折试验中发现，弯折引起的扰动在强减阻情况下不易消失，高速和低速两个区域的存在一直持续到发生强剪切。我们还发现，在弯曲的外部部分几乎没有扰动。少

The purpose of our project is to clarify the flow mechanism of surfactant solution, which exhibits drastic drag reduction in a piping system. 'lb achieve this purpose, we made the experimental apparatus containing a straight circular cross sectional pipe and the bend with the curvature ratio (bend curvature divided by inner radius of pipe) of four, and conducted the investigation of rheological characteristics, pressure measurement, and WV measurement. Finally, we fried to explain the drug reducing effect relating with those results. These would to be valuable for an innovation of the new drug reduction technique. The result of the rheological characteristics investigation showed that our examining surfactant solution (LSP-01M) could also become the shear induced state(SIS)that was common in many surfactant solutions. In the experiment using a straight pipe, the developing process of the boundary layer was clarified in the case of surfactant solution. We also showed that the maximum dr … More ug reduction ratio exceeded over 70%, and that drug reduction effect did not completely disappear in the case of weight concentration of 50 ppm when increasing Reynolds number. The velocity distribution in the wall coordinate system was also provided. Velocity measurement were carried out in detail, and it was hind that the Reynolds shear stress, which is correlation of axial and radial velocity fluctuations, were suppressed by malting the symmetric distribution of the probability density function against outward interaction and ejection, inward interaction and sweep, respectively. It was also found that the apparent viscosity slightly apart from the wall coincided with that of SIS, and there was the region with smaller apparent viscosity adjacent to the wall. We explained the reason of suppression of Reynolds shear stress, utilizing this gradient of apparent viscosity. In the experiment using the bend, it was found that the disturbance induced by the bend could not vanish easily in the case of strong drag reduction, and that the existence of two regions with high and low velocities lasted until they made strong shear. We also found that there was little disturbance in the outer part of the bend. Less