Characterization of far-field wake instabilities of marine propellers with barnacles

This study investigates the impact of barnacle attachment on the wake characteristics of marine propellers, focusing on the evolution from the near-field to the far-field regions. Using the improved delayed detached-eddy simulation (IDDES) method on an unstructured grid with 50.7 × 106 cells, the research explores the specific effects and mechanisms of barnacle structures on propeller wake evolution by examining vortex dynamics, Reynolds stresses distribution, and energy transfer mechanisms in the wake. The results indicate that barnacle attachment significantly disrupts the coherence of the wake flow field, leading to premature wake instability as coherent vortical structures break up and evolve into the far wake. The simulations also reveal the instability mechanism caused by barnacles, where barnacles induce small-scale vortices that interact with tip vortices, intensifying the mutual inductance process, promoting turbulence generation and coherent structure instability. These findings provide valuable insights into the impact of biofouling on propeller wake dynamics.