Drag Reduction Characteristics of Bionic Structure Composed of Grooves and Mucous Membrane Acting on Turbulent Boundary Layer

Abstract

The biological surface structure comprising fish scales and a mucous membrane exhibits good turbulent drag reduction ability. Based on this structure, a bionic frictional drag reduction model composed of a grooved structure and mucous membrane was established herein, and its efficacy in reducing the resistance of a turbulent boundary layer was analyzed. Accordingly, the drag reduction performance of the bionic structure was investigated through large eddy simulations. The results revealed that the mucous membrane was evenly distributed on the groove wall through secretion, and effectively improved the drag reduction rate of the groove wall. The bionic grooves and mucous membrane structure successfully inhibited the turbulent kinetic energy, turbulence intensity, and Reynolds stress. The grooved structure improved the shape of the Λ vortex structure and the mucous membrane reduced the number of three-dimensional (3D) vortex structures. Furthermore, the streak structure near the bionic structure wall was reduced and its shape was regularized, which intuitively demonstrates the turbulence suppression ability of the proposed bionic structure. This paper presents the results of a hydrodynamic analysis of the frictional drag reduction characteristics of a bionic structure consisting of grooves and viscous membranes acting on the turbulent boundary layer of a wall.

Particle separation mechanisms in suspension-feeding fishes: key questions and future directions

“…Therefore, he concluded that menhaden use mechanical sieving to retain particles on the branchiospinules. Another productive future approach could be to incorporate synthetic hydrogels and other mucus analogues (e.g., Authimoolam and Dziubla, 2016;Bej and Haag, 2022) into computational models as done with drag-reducing agents and microgrooves (Zhang et al, 2022a), or into physical models as suggested by Witkop et al (2023).…”

Energy harvesting of flow induced vibration enhanced by bionic non-smooth surfaces

“…Research shows that the aerodynamics of PEHs can be changed by changing its surface structure, and its vibration mode can be signi cantly affected, thus improving its performance [30]. Zhang et al [31] studied the sh scale shape of the groove surface structure, designed its shape, and visually displayed the in uence of the structure on turbulence. Yang et al [32] studied the in uence and control of non-smooth body structure on vehicle tail vortex.…”