Numerical investigation of wave attenuation by coupled flexible vegetation dynamic model and XBeach wave model

Abstract Quantitative investigation of wave attenuation by flexible vegetation is an increasingly prominent area in wave mechanics. Given that the existing XBeach non-hydrostatic wave model can only simulate wave attenuation by rigid vegetation, a mechanical model for simulating submerged flexible vegetation dynamics driven by waves and a coupling simulation method between the flexible vegetation dynamic model and the XBeach non-hydrostatic wave model were proposed. To assess the performance of the proposed coupled model, a wave flume experiment was conducted. This study demonstrates the validity of the new flexible vegetation dynamic model in simulating forces and motions of a single submerged flexible stem. The validation between modeled results and experimental data shown that the coupled model is capable of reproducing the wave attenuation in the presence of flexible vegetation. The above results further indicate that the coupling implementation is valid and reliable. Besides, this study further confirms that flexible vegetation is able to attenuate wave height, and the elasticity modulus of flexible vegetation plays a vital role in wave attenuation when all the other variables are invariant. This study can broaden the application of the XBeach model and provide technical support for the engineering practice of coastal nature-based solutions.