The 12th International Conference on Hydrodynamics
18 – 23 september 2016, Egmond aan Zee, The Netherlands
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STUDY OF MICROBUBBLES FOR SKIN-FRICTION DRAG REDUCTION


Go-down ichd2016 Tracking Number 139

Presentation:
Session: Cavitation and cavitating flows II
Room: Room 4
Session start: 16:00 Tue 20 Sep 2016

Yan Yao   yaoyanyy@163.com
Affifliation:

Jin-ling Luo   welcomji@vip.sina.com
Affifliation:

Kun Zhu   zhukun@163.com
Affifliation:

Hai-bo He   hehaibo@sina.com
Affifliation:

Rui Wu   279057081@qq.com
Affifliation: 279057081

Shi-jie Qin   qinshijie@zju.edu.cn
Affifliation: Institute of Process Equipment, Zhejiang University,


Topics: - Cavitation and cavitating flows

Abstract:

In this paper, the numerical simulation method and experimental test are applied to research and analyze the drag reduction performance of microbubbles. It presents numerical simulations of external flow over a flat porous surface with blowing crossflow that result in significant drag reduction at the interface between the boundary layer and the solid wall. Using the gas-liquid two-phase flow model to simulate the drag reduction efficiency. Through parametric numerical experiments it is demonstrated that it is fundamentally possible to achieve a reduction in the shear force on the wall. The influences between the drag reduction performance and factors of gas velocity, free-stream velocity, downstream distance from the injector are analyzed. And the streamwise velocity developing tendency and bubbles distribution of boundary layer are discussed. During the experimental testing, the equipment is tested in the water tunnel. The experimental results mutually coincide with the simulation analysis. It shows that the drag reduction technology of the microbubbles can significantly reduce frictional resistance of the solid wall. The results showed that when the gas velocity was increased, the friction resistance reduction increased.