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Drag-reduction Characteristics of Bionic-Based Structure Composed of Grooves and Mucous Membrane Acting on Turbulent Boundary Layer
Author(s): Kaisheng Zhang, Chaofan Ma, Jing Zhang, Baocheng Zhang, Bo Zhao
Keywords: mucous membrane; bionic drag reduction; viscoelastic fluid; turbulence statistics; coherent structure
The surface structure consisting of fish scale and mucous membrane has good turbulence drag-reduction ability. Inspired by this phenomenon, the bionic frictional drag-reduction model composed of groove structure and mucus membrane was first established. Based on this model, the drag-reduction performance of bionic-based structure acting on the classical wall turbulent boundary layer are investigated by large eddy simulation. Results show that the mucous membrane can be evenly distributed on the groove wall by secretion, which effectively improves the drag reduction rate on the groove wall. The bionic grooves and mucous membrane have inhibitory effects on turbulent kinetic energy, turbulence intensity and Reynolds stress. The groove structure can improve the shape of the Λ vortex structure and the mucous membrane can reduce the number of the three-dimensional (3D) vortex structure. Meanwhile, the streak structure near the bionic structure wall is reduced and the shape is regularized, which more intuitively shows that the turbulence is suppressed by this model. This paper presents a hydrodynamic analysis of the frictional drag reduction characteristics of the bionic structure consisting of grooves and viscous membranes acting on the turbulent boundary layer of the wall.

Journal of Applied Fluid Mechanics

The Journal of Applied Fluid Mechanics (JAFM) is an international, peer-reviewed journal which covers a wide range of theoretical, numerical and experimental aspects in fluid mechanics. The emphasis is on the applications in different engineering fields rather than on pure mathematical or physical aspects in fluid mechanics. Although many high quality journals pertaining to different aspects of fluid mechanics presently exist, research in the field is rapidly escalating.