An experimental study was performed to investigate the effects of the extensional rheological properties of polymer solutions on vortex deformation in turbulent flow and turbulent statistics. To focus on the extensional properties, a self-standing two-dimensional (2D) turbulent flow was used as an experimental setup, and the flow was observed through interference patterns and particle image velocimetry (PIV). Vortex shedding and the resulting deformation in the 2D flow were categorized into three types. The vortex flow regime was defined by the shedding frequency and relaxation time of the polymer solution. Turbulent energy was suppressed by polymer additives; however, a characteristic peak reappeared with increasing concentration. The results imply that the characteristic turbulent energy peak is influenced by the relaxation process of the extended polymers in the flow.

进行了一项实验研究，以研究聚合物溶液的延伸流变特性对湍流和湍流统计中涡旋变形的影响。为了关注拉伸特性，将自立式二维（2D）湍流用作实验装置，并通过干涉图和粒子图像测速（PIV）观察了该流动。二维流中的涡旋脱落和所产生的变形可分为三种类型。涡流状态由聚合物溶液的脱落频率和弛豫时间定义。湍流能量被聚合物添加剂抑制；但是，随着浓度的增加，会出现一个特征峰。