SPH Simulation Of Hydrodynamic Responses For Silt Curtain Under Combined Wave-Current Conditions

Silt curtain,which is generally composed of a curtain body of flexible geotextile,is widely used as an isolation structure in dredging and land reclamation activities,aiming at preventing the spread of suspended matters.Now with the enhancement on its material strength of the geotextile,novel applications of the silt curtain were attempted in more violent hydrodynamic conditions,such as an isolation structure to prevent sediment transportation into channels and ports with a combined wave and current environment.The details are as follows:(1)Two kinds of silt curtain were considered in this study: one is the emerged mode which forms an entire barrier to the water body considering the impact of water pressure head(WPH)and WPH-wave,while the other is the submerged mode which resist the downside part of the water body considering current and current-wave.(2)A Smoothed Particle Hydrodynamics(SPH)model was applied to simulate the interaction between a flexible impermeable curtain system and fluid,in which the rigid module connected with flexible connector(RMFC)was used to simulate the curtain body,the numerical box was added to set up accurate WPHs automatically,the continuous open boundary was used to create a current condition and an activeabsorption wave paddle was adopted to generate waves.(3)A newly-developed overlapped particle method(OPM)was added to the model to calculate the fluid pressure around the flexible thin-walled structure more precisely.Through the simulation of the SCS under various working conditions,it was found that the modeled results of tensions in the curtain are in good consistence with the theoretical and experimental results,which demonstrates the accuracy and robustness of the improved model.(4)Comparing and analyzing the two modes,the SCS in submerged mode was found to be subject to much smaller tensions than in emerged mode and meanwhile the SCS in emerged mode imposes much more significant influence of reflection and energy dissipation on wave transmission than in submerged mode.