Title of article :
Drag Reduction Characteristics of Bionic Structure Composed of Grooves and Mucous Membrane Acting on Turbulent Boundary Layer
Author/Authors :
Zhang, K Department of Mechanical Engineering - College of Engineering - Ocean University of China - Qingdao 266100 - China - Key Laboratory of Ocean Engineering of Shandong Province - Ocean University of China - Qingdao 266100 - China , Ma, C Department of Mechanical Engineering - College of Engineering - Ocean University of China - Qingdao 266100 - China - Key Laboratory of Ocean Engineering of Shandong Province - Ocean University of China - Qingdao 266100 - China , Zhang, J Department of Chemistry - College of Chemistry and Chemical Engineering - Ocean University of China - Qingdao 266100, China , Zhang, B Department of Mechanical Engineering - College of Engineering - Ocean University of China - Qingdao 266100 - China - Key Laboratory of Ocean Engineering of Shandong Province - Ocean University of China - Qingdao 266100 - China , Zhao, B Department of Mechanical Engineering - College of Engineering - Ocean University of China - Qingdao 266100 - China - Key Laboratory of Ocean Engineering of Shandong Province - Ocean University of China - Qingdao 266100 - China
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.
Keywords :
Mucous membrane , Bionic drag reduction , Viscoelastic fluid , Turbulence statistics , Coherent structure
Journal title :
Journal of Applied Fluid Mechanics (JAFM)
