Drag Reduction Characteristics of Bionic Mucous Membrane Acting on the Turbulent Boundary Layer

The mucous membrane on the fish surface has excellent drag reduction performance. The mucous membrane can be regarded as the viscoelastic fluid, and a bionic friction drag reduction model is proposed with the consideration of a Carreau viscoelastic model-based mucus secretion process. Then, the drag reduction effect of the mucous membrane on the classical wall turbulence boundary layer is investigated by large-eddy simulations. Results show that the bionic mucous membrane is conducive to reducing the turbulence, and can achieve a drag reduction rate of about 14%. This study provides a hydrodynamics understanding of the drag reduction characteristics of the bionic mucous membrane.