Hydrodynamic Effects and Scour Protection of a Geotextile Mattress with a Floating Plate

In this study, the evolution of the flow field near a Geotextile Mattress with a Floating Plate (GMFP) are numerically investigated, with a specific focus on the influence of the Froude number and the dynamic response of the floating plate. Key findings identify a critical Froude number that separates two protection regimes. Below this critical flow condition, the bottom vortex and the protective zone remain stable. Above it, the vortex contracts upstream, and the protection efficacy becomes substantial but diminished due to the competing effects of vortex development and a reduction in plate obstruction height. The bed shear stress over a considerable distance leeward of the GMFP is significantly reduced compared to unprotected conditions. Due to the blockage of the GMFP, upstream backup and downstream drawdown were observed in the water surface over the GMFP. These results provide valuable insights for the design and application of GMFPs, particularly in optimizing structural parameters to enhance protection effectiveness under varying flow conditions.