Abstract: 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. Key

Key words: underwatervehicle, dragreductioncharacteristic, microbubble, polymer, watertunnelexperiment