Airfoil profile surface drag reduction characteristics based on the structure of the mantis shrimp abdominal segment

To reduce the drag of fluid on a surface, the parameterized structure of the mantis shrimp abdominal segment was analyzed to design the airfoil profile, and a calculation model was established based on the biological characteristics of the mantis shrimp. By using a numerical simulation method, the change in the viscous sublayer and drag reduction of the biological surface under different flow velocities and with different numbers of airfoil profiles was analyzed, and the mechanism of the drag reduction of the biological airfoil profile was revealed. The results show that the biological surface with airfoil profiles exhibited a better drag reduction effect. With an increase in airfoil profile numbers, the drag reduction rate first decreased and then increased. When the flow velocity was 10 m/s and the number of airfoil profiles was 5, the drag reduction rate exhibited the largest value of 15.33%. This result showed that the biological airfoil profile could affect the structure of the wall turbulent boundary layer and diminish the velocity gradient of the boundary layer, which finally changed the interaction pattern between the fluid and wall. In addition, the vortex cushioning effect was created to change the friction between the fluid and the wall into a rolling friction with a lower friction coefficient, thus reducing the shear stress on the wall, which achieved drag reduction.