【摘要】 本文应用PIV(ParticleImageVelocimetry)和PDA(PhaseDopplerAnemometry)在二维流道内对CTAC(CetyltrimethylAmmoniumChloride)减阻流体湍流流场进行试验研究,得到减阻流体湍流速度分布。研究表明:在完全减阻区内,减阻流体的减阻性能随雷诺数的增大而增大,在过渡减阻区内,减阻流体的摩擦系数则随着雷诺数的增大而逐渐回升,最终回到与溶剂相当的水平上;减阻流体的速度分布曲线在近壁面处与牛顿流体层状速度曲线趋近,但二者并不完全重合;在流道近壁面处,水湍流流动时所能观测到的强烈的旋涡波动在减阻流体中基本消失,与此同时,在此区域内减阻流体的速度轮廓线与流道几乎平行,且该平行轮廓线部分所占比例较牛顿流体湍流流动时相应部分要大很多,减阻流体的湍流强度受到了极大的抑制。更多还原

【Abstract】 An experimental study was conducted of the turbulent flow field of a CTAC drag reducing fluid in a two dimensional flow channel with the use of PIV (particle image velocimetry) and PDA (Phase Doppler Anemometry). As a result, the turbulent flow speed distribution of the drag reducing fluid was obtained. The results of the study indicate that in a fully drag reducing zone the drag reducing performance of the drag reducing fluid will increase with an increase in Reynolds number. In a transitional drag reducing zone the friction factor of the drag reducing fluid will gradually ascend with an increase in Reynolds number, and finally return to a level comparable to that of a solvent. The speed distribution curves of the drag reducing fluid at the near wall surface will tend to approximate to the laminar speed curves of a Newtonian fluid, but there lacks a total congruence of these two curves. At the near wall surface of the flow channel the intensive vortex fluctuations observable at the time of water turbulent flows will basically disappear in the drag reducing fluid. In the meantime the speed contour line of the drag reducing fluid in the above zone will be nearly parallel to the flow channel. In addition, the portion occupied by the parallel contour line is much greater than the corresponding portion taken up during the turbulent flow of the Newtonian fluid, thus drastically suppressing the turbulent flow intensity of the drag reducing fluid.更多还原