A peridynamic-lattice Boltzmann-immersed boundary hybrid model for fluid interactions with low-density flexible structures

The coupling of peridynamics model and lattice Boltzmann method using immersed boundary method can effectively simulate strong fluid structure interactions. However, the current hybrid models fail to describe flow-induced large deformation, fracture and damage of low-density structures, which restricts their applications in engineering design simulations. To overcome this restriction, we propose an advanced algorithm that implements velocity correction points throughout the solid subdomains, where strong coupling through simultaneous velocity corrections in both solid structures modelled with peridynamics and fluid domains solved with lattice Boltzmann method is implemented at each time step, utilizing an implicit velocity correction scheme. Consequently, this method enables the simulation of large deformation and fracture of low-density flexible structures, as validated by a range of benchmark cases. Therefore, the proposed peridynamic-lattice Boltzmann-immersed boundary hybrid model is capable of simulating strong fluid structure interactions across a range of structural densities—whether greater than, less than, or equal to the fluid density. In addition, the present scheme significantly improves computational accuracy for fluid structure interactions with rotational structures.