Velocity error and consequences of the feedback immersed boundary method*

This talk presents a study on velocity error and consequences of the feedback immersed boundary method (IBM), which is implemented with the lattice Boltzmann method for solving the fluid dynamics. The IBM is implemented in non-iterative (with and without velocity prediction step) and iterative ways. A few benchmark cases will be introduced to demonstrate the performance of the three implementations. Results show that both the IBM with prediction step, the iterative IBM and one iteration IBM with proper feedback coefficients can suppress the spurious flow penetration on the solid wall. While the velocity error does not significantly affect the force production and structure deformation for external flows, reducing it significantly improves the prediction of the force distribution and structure deformation for internal flows. In addition, the iterative IBM with smaller feedback coefficient has better numerical stability.