Study on Drag Reduction Characteristic Around Bodies of Revolution with Bionic Non-smooth Surface

Bionic non-smooth structures on the bodies of revolution had characteristic of drag reduction. In this paper, oil flow visualization test were made in low speed wind tunnel between two bionic non-smooth surface models and smooth surface model. The results show that the oil flow pattern is significantly difference according to the configuration of non-smooth structures, and had obviously effect on the friction of the model. However, the total drag coefficient of BNNS model is reduced. It was found that the BNSS can decrease the pressure drag obviously. The mechanism of BNSS is through sacrifice small viscous force, early flow separation on the blunt body of revolution was restrained, and the pressure force reduced dramatically, so the total force reduced also. Key words: Oil flow visualization; drag reduction; non-smooth surface; bionic