微气泡与聚合物对水下航行体减阻特性影响试验研究

为研究微气泡与聚合物对水下航行体减阻特性影响，采用微孔材料并基于高速摄像系统和测力系统，针对微气泡与聚合物共同作用下水下航行体减阻特性开展水洞试验研究。基于高速摄像系统对比分析了不同速度和通气量下微气泡流形态变化规律；基于测力系统对比分析了微气泡和聚合物共同作用下航行体减阻特性变化规律。试验结果表明：采用微孔材料的航行体微气泡流均匀分布在航行体表面，模型尾部微气泡流上漂现象较为明显，且上漂的微气泡始终为离散形态；对于未通气状态下的聚合物减阻，在相同来流速度下，减阻效果随着聚合物浓度增加而增大，但存在聚合物饱和效应，且饱和聚合物浓度值随着来流速度增加而减小；聚合物和微气泡联合减阻效率大于单独一种减阻方式；在来流速度较小时，聚合物溶液减阻率随着通气量增加而逐渐增大，但随着聚合物溶液浓度增加，微气泡减阻率差异逐渐减小并最终趋于一致。

Influences of Microbubble and Homogeneous Polymer on Drag Reduction Characteristics of Axisymmetric Body

To reduce the drag of underwater vehicle, the experiment of axisymmetric body is conducted to study the combined drag reduction effect of microbubble injection and the homogeneous polymer solutions by using the high speed camera system and six-component balance system. The axisymmetric body is constructed with sintered porous material. The morphologic changes of microbubble flow are analyzed based on the high speed camera system, and the drag reduction characteristics of axisymmetric body are obtained by the six-component balance system. The experimental results show that the microbubbles are uniformly dispersed throughout the surface of the experimental model. The floating-upward phenomenon of microbubbles is distinct when the microbubbles reach the tail of the experimental model with the dispersed microbubbles. The drag reduction efficiency of combination of microbubbles and homogeneous polymer is larger than that of individual one. With the increase in air injection rate, the drag reduction rates of various homogeneous polymer solutions are all gradually increased but the difference among them declines. As the density of individual homogeneous polymer solution increases, the drag reduction rate of individual homogeneous polymer solution increases as well with the homogeneous polymer saturation effect. The saturation density decreases with the increase in free stream speed.